diff --git a/libs/vr/libvrflinger/Android.mk b/libs/vr/libvrflinger/Android.mk
new file mode 100644
index 0000000..6b5e7cc
--- /dev/null
+++ b/libs/vr/libvrflinger/Android.mk
@@ -0,0 +1,87 @@
+# Copyright (C) 2008 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+LOCAL_PATH := $(call my-dir)
+
+sourceFiles := \
+	acquired_buffer.cpp \
+	compositor.cpp \
+	debug_hud_data.cpp \
+	debug_hud_view.cpp \
+	display_manager_service.cpp \
+	display_service.cpp \
+	display_surface.cpp \
+	epoll_event_dispatcher.cpp \
+	hardware_composer.cpp \
+	screenshot_service.cpp \
+	surface_channel.cpp \
+	video_compositor.cpp \
+	video_mesh_surface.cpp \
+	vr_flinger.cpp \
+	vsync_service.cpp
+
+includeFiles := $(LOCAL_PATH)/include
+
+staticLibraries := \
+	libsurfaceflingerincludes \
+	libhwcomposer-command-buffer \
+	libbufferhub \
+	libbufferhubqueue \
+	libeds \
+	libdisplay \
+	libdvrcommon \
+	libdvrgraphics \
+	libperformance \
+	libsensor \
+	libpdx_default_transport \
+
+sharedLibraries := \
+	android.dvr.composer@1.0 \
+	android.hardware.graphics.allocator@2.0 \
+	android.hardware.graphics.composer@2.1 \
+	libbinder \
+	libbase \
+	libcutils \
+	liblog \
+	libhardware \
+	libutils \
+	libEGL \
+	libGLESv1_CM \
+	libGLESv2 \
+	libvulkan \
+	libui \
+	libgui \
+	libsync \
+	libhidlbase \
+	libhidltransport \
+	libfmq \
+
+include $(CLEAR_VARS)
+LOCAL_SRC_FILES := $(sourceFiles)
+LOCAL_C_INCLUDES := $(includeFiles)
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(includeFiles)
+
+LOCAL_CFLAGS += -DLOG_TAG=\"vr_flinger\"
+LOCAL_CFLAGS += -DTRACE=0
+LOCAL_CFLAGS += -DATRACE_TAG=ATRACE_TAG_GRAPHICS
+LOCAL_CFLAGS += -DGL_GLEXT_PROTOTYPES -DEGL_EGLEXT_PROTOTYPES
+ifeq ($(TARGET_USES_QCOM_BSP), true)
+    LOCAL_C_INCLUDES += hardware/qcom/display/libgralloc
+    LOCAL_C_INCLUDES += hardware/qcom/display/libqdutils
+    LOCAL_SHARED_LIBRARIES += libqdutils
+endif
+LOCAL_SHARED_LIBRARIES := $(sharedLibraries)
+LOCAL_WHOLE_STATIC_LIBRARIES := $(staticLibraries)
+LOCAL_MODULE := libvrflinger
+include $(BUILD_STATIC_LIBRARY)
diff --git a/libs/vr/libvrflinger/acquired_buffer.cpp b/libs/vr/libvrflinger/acquired_buffer.cpp
new file mode 100644
index 0000000..5a3aa7f
--- /dev/null
+++ b/libs/vr/libvrflinger/acquired_buffer.cpp
@@ -0,0 +1,100 @@
+#include "acquired_buffer.h"
+
+#include <log/log.h>
+#include <sync/sync.h>
+
+using android::pdx::LocalHandle;
+
+namespace android {
+namespace dvr {
+
+AcquiredBuffer::AcquiredBuffer(const std::shared_ptr<BufferConsumer>& buffer,
+                               LocalHandle acquire_fence, uint64_t /*sequence*/)
+    : buffer_(buffer), acquire_fence_(std::move(acquire_fence)) {}
+
+AcquiredBuffer::AcquiredBuffer(const std::shared_ptr<BufferConsumer>& buffer,
+                               int* error) {
+  LocalHandle fence;
+  const int ret = buffer->Acquire(&fence);
+
+  if (error)
+    *error = ret;
+
+  if (ret < 0) {
+    ALOGW("AcquiredBuffer::AcquiredBuffer: Failed to acquire buffer: %s",
+          strerror(-ret));
+    buffer_ = nullptr;
+    // Default construct sets acquire_fence_ to empty.
+  } else {
+    buffer_ = buffer;
+    acquire_fence_ = std::move(fence);
+  }
+}
+
+AcquiredBuffer::AcquiredBuffer(AcquiredBuffer&& other)
+    : buffer_(std::move(other.buffer_)),
+      acquire_fence_(std::move(other.acquire_fence_)) {}
+
+AcquiredBuffer::~AcquiredBuffer() { Release(LocalHandle(kEmptyFence)); }
+
+AcquiredBuffer& AcquiredBuffer::operator=(AcquiredBuffer&& other) {
+  if (this != &other) {
+    Release(LocalHandle(kEmptyFence));
+
+    buffer_ = std::move(other.buffer_);
+    acquire_fence_ = std::move(other.acquire_fence_);
+  }
+  return *this;
+}
+
+bool AcquiredBuffer::IsAvailable() const {
+  if (IsEmpty())
+    return false;
+
+  // Only check the fence if the acquire fence is not empty.
+  if (acquire_fence_) {
+    const int ret = sync_wait(acquire_fence_.Get(), 0);
+    ALOGD_IF(TRACE || (ret < 0 && errno != ETIME),
+             "AcquiredBuffer::IsAvailable: acquire_fence_=%d sync_wait()=%d "
+             "errno=%d.",
+             acquire_fence_.Get(), ret, ret < 0 ? errno : 0);
+    if (ret == 0) {
+      // The fence is completed, so to avoid further calls to sync_wait we close
+      // it here.
+      acquire_fence_.Close();
+    }
+    return ret == 0;
+  } else {
+    return true;
+  }
+}
+
+LocalHandle AcquiredBuffer::ClaimAcquireFence() {
+  return std::move(acquire_fence_);
+}
+
+std::shared_ptr<BufferConsumer> AcquiredBuffer::ClaimBuffer() {
+  return std::move(buffer_);
+}
+
+int AcquiredBuffer::Release(LocalHandle release_fence) {
+  if (buffer_) {
+    // Close the release fence since we can't transfer it with an async release.
+    release_fence.Close();
+    const int ret = buffer_->ReleaseAsync();
+    if (ret < 0) {
+      ALOGE("AcquiredBuffer::Release: Failed to release buffer %d: %s",
+            buffer_->id(), strerror(-ret));
+      if (ret != -ESHUTDOWN)
+        return ret;
+    }
+
+    buffer_ = nullptr;
+    acquire_fence_.Close();
+  }
+
+  return 0;
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/acquired_buffer.h b/libs/vr/libvrflinger/acquired_buffer.h
new file mode 100644
index 0000000..050cd5f
--- /dev/null
+++ b/libs/vr/libvrflinger/acquired_buffer.h
@@ -0,0 +1,82 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_ACQUIRED_BUFFER_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_ACQUIRED_BUFFER_H_
+
+#include <pdx/file_handle.h>
+#include <private/dvr/buffer_hub_client.h>
+
+#include <memory>
+
+namespace android {
+namespace dvr {
+
+// Manages the ACQUIRE/RELEASE ownership cycle of a BufferConsumer.
+class AcquiredBuffer {
+ public:
+  static constexpr int kEmptyFence = pdx::LocalHandle::kEmptyFileHandle;
+
+  AcquiredBuffer() : buffer_(nullptr), acquire_fence_(kEmptyFence) {}
+
+  // Constructs an AcquiredBuffer from a BufferConsumer pointer and an acquire
+  // fence. The BufferConsumer MUST be in the ACQUIRED state prior to calling
+  // this constructor; the constructor does not attempt to ACQUIRE the buffer
+  // itself.
+  AcquiredBuffer(const std::shared_ptr<BufferConsumer>& buffer,
+                 pdx::LocalHandle acquire_fence, uint64_t sequence);
+
+  // Constructs an AcquiredBuffer from a BufferConsumer. The BufferConsumer MUST
+  // be in the POSTED state prior to calling this constructor, as this
+  // constructor attempts to ACQUIRE the buffer. If ACQUIRING the buffer fails
+  // this instance is left in the empty state. An optional error code is
+  // returned in |error|, which may be nullptr if not needed.
+  AcquiredBuffer(const std::shared_ptr<BufferConsumer>& buffer, int* error);
+
+  // Move constructor. Behaves similarly to the move assignment operator below.
+  AcquiredBuffer(AcquiredBuffer&& other);
+
+  ~AcquiredBuffer();
+
+  // Move assignment operator. Moves the BufferConsumer and acquire fence from
+  // |other| into this instance after RELEASING the current BufferConsumer and
+  // closing the acquire fence. After the move |other| is left in the empty
+  // state.
+  AcquiredBuffer& operator=(AcquiredBuffer&& other);
+
+  // Accessors for the underlying BufferConsumer, the acquire fence, and the
+  // use-case specific sequence value from the acquisition (see
+  // dreamos/buffer_hub_client.h).
+  std::shared_ptr<BufferConsumer> buffer() const { return buffer_; }
+  int acquire_fence() const { return acquire_fence_.Get(); }
+
+  // When non-empty, returns true if the acquired fence was signaled (or if the
+  // fence is empty). Returns false when empty or if the fence is not signaled.
+  bool IsAvailable() const;
+
+  bool IsEmpty() const { return buffer_ == nullptr; }
+
+  // Returns the acquire fence, passing ownership to the caller.
+  pdx::LocalHandle ClaimAcquireFence();
+
+  // Returns the buffer, passing ownership to the caller. Caller is responsible
+  // for calling Release on the returned buffer.
+  std::shared_ptr<BufferConsumer> ClaimBuffer();
+
+  // Releases the BufferConsumer, passing the release fence in |release_fence|
+  // to the producer. On success, the BufferConsumer and acquire fence are set
+  // to empty state; if release fails, the BufferConsumer and acquire fence are
+  // left in place and a negative error code is returned.
+  int Release(pdx::LocalHandle release_fence);
+
+ private:
+  AcquiredBuffer(const AcquiredBuffer&) = delete;
+  void operator=(const AcquiredBuffer&) = delete;
+
+  std::shared_ptr<BufferConsumer> buffer_;
+  // Mutable so that the fence can be closed when it is determined to be
+  // signaled during IsAvailable().
+  mutable pdx::LocalHandle acquire_fence_;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_ACQUIRED_BUFFER_H_
diff --git a/libs/vr/libvrflinger/compositor.cpp b/libs/vr/libvrflinger/compositor.cpp
new file mode 100644
index 0000000..5a111d4
--- /dev/null
+++ b/libs/vr/libvrflinger/compositor.cpp
@@ -0,0 +1,873 @@
+#include "compositor.h"
+
+#include <EGL/eglext.h>
+#include <GLES/gl.h>
+#include <GLES/glext.h>
+#include <GLES2/gl2.h>
+
+#include <memory>
+
+#include <cutils/properties.h>
+
+#include <dvr/graphics.h>
+#include <private/dvr/buffer_hub_client.h>
+#include <private/dvr/clock_ns.h>
+#include <private/dvr/debug.h>
+#include <private/dvr/display_types.h>
+#include <private/dvr/dummy_native_window.h>
+#include <private/dvr/gl_fenced_flush.h>
+#include <private/dvr/graphics/blur.h>
+#include <private/dvr/graphics/gpu_profiler.h>
+#include <private/dvr/lucid_metrics.h>
+#include <private/dvr/native_buffer.h>
+#include <private/dvr/platform_defines.h>
+#include <utils/Log.h>
+#include <utils/Trace.h>
+
+#include "debug_hud_data.h"
+#include "debug_hud_view.h"
+#include "display_surface.h"
+
+#define BINNING_CONTROL_HINT_QCOM 0x8FB0
+
+// Accepted by the <hint> parameter of glHint:
+#define BINNING_QCOM 0x8FB1
+#define VISIBILITY_OPTIMIZED_BINNING_QCOM 0x8FB2
+#define RENDER_DIRECT_TO_FRAMEBUFFER_QCOM 0x8FB3
+
+#ifndef EGL_CONTEXT_MAJOR_VERSION
+#define EGL_CONTEXT_MAJOR_VERSION 0x3098
+#define EGL_CONTEXT_MINOR_VERSION 0x30FB
+#endif
+
+using android::pdx::LocalHandle;
+
+static const int kDistortionMeshResolution = 40;
+
+static std::shared_ptr<int64_t> eds_gpu_duration_ns =
+    std::make_shared<int64_t>(0);
+
+static constexpr char kDisableLensDistortionProp[] =
+    "persist.dreamos.disable_distort";
+
+static constexpr char kEnableEdsPoseSaveProp[] =
+    "persist.dreamos.save_eds_pose";
+
+namespace android {
+namespace dvr {
+
+namespace {
+
+// An implementation of ANativeWindowBuffer backed by a temporary IonBuffer.
+// Do not hold on to this kind of object, because the IonBuffer may become
+// invalid in other scopes.
+class TemporaryNativeBuffer
+    : public ANativeObjectBase<ANativeWindowBuffer, TemporaryNativeBuffer,
+                               LightRefBase<TemporaryNativeBuffer>> {
+ public:
+  explicit TemporaryNativeBuffer(const IonBuffer* buffer) : BASE() {
+    ANativeWindowBuffer::width = buffer->width();
+    ANativeWindowBuffer::height = buffer->height();
+    ANativeWindowBuffer::stride = buffer->stride();
+    ANativeWindowBuffer::format = buffer->format();
+    ANativeWindowBuffer::usage = buffer->usage();
+    // TODO(eieio): Update NYC to support layer_count.
+    // ANativeWindowBuffer::layer_count = 1;
+    handle = buffer->handle();
+  }
+
+ private:
+  friend class android::LightRefBase<TemporaryNativeBuffer>;
+
+  TemporaryNativeBuffer(const TemporaryNativeBuffer&) = delete;
+  void operator=(TemporaryNativeBuffer&) = delete;
+};
+
+std::vector<uint8_t> ReadTextureRGBA(GLuint texture_id, int width, int height) {
+  std::vector<uint8_t> data(width * height * 4);
+  GLuint fbo;
+  glGenFramebuffers(1, &fbo);
+  glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+  glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
+                         texture_id, 0);
+  // Using default GL_PACK_ALIGNMENT of 4 for the 4 byte source data.
+  glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data.data());
+  glBindFramebuffer(GL_FRAMEBUFFER, 0);
+  glDeleteFramebuffers(1, &fbo);
+  CHECK_GL();
+  return data;
+}
+
+}  // namespace
+
+class Compositor::Texture {
+ public:
+  Texture(std::shared_ptr<BufferConsumer> consumer, EGLDisplay display,
+          int index);
+  ~Texture();
+
+  std::shared_ptr<BufferConsumer> consumer() const { return consumer_; }
+  GLuint texture_id() const { return texture_id_; }
+  vec2i size() const {
+    return vec2i(native_buffer_.get()->width, native_buffer_.get()->height);
+  }
+  int index() const { return index_; }
+
+  bool Initialize();
+
+ private:
+  Texture(const Texture&) = delete;
+  void operator=(const Texture&) = delete;
+
+  std::shared_ptr<BufferConsumer> consumer_;
+
+  android::sp<NativeBufferConsumer> native_buffer_;
+
+  EGLDisplay display_;
+  EGLImageKHR image_;
+  GLuint texture_id_;
+  int index_;
+};
+
+Compositor::Texture::Texture(std::shared_ptr<BufferConsumer> consumer,
+                             EGLDisplay display, int index)
+    : consumer_(consumer),
+      display_(display),
+      image_(nullptr),
+      texture_id_(0),
+      index_(index) {}
+
+Compositor::Texture::~Texture() {
+  glDeleteTextures(1, &texture_id_);
+  eglDestroyImageKHR(display_, image_);
+}
+
+bool Compositor::Texture::Initialize() {
+  native_buffer_ = new NativeBufferConsumer(consumer_, index_);
+
+  CHECK_GL();
+  image_ = eglCreateImageKHR(
+      display_, EGL_NO_CONTEXT, EGL_NATIVE_BUFFER_ANDROID,
+      static_cast<ANativeWindowBuffer*>(native_buffer_.get()), nullptr);
+  if (!image_) {
+    ALOGE("Failed to create EGLImage\n");
+    return false;
+  }
+
+  glGenTextures(1, &texture_id_);
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_2D, texture_id_);
+  glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, image_);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+  CHECK_GL();
+  return true;
+}
+
+Compositor::RenderTarget::RenderTarget()
+    : buffer_texture_id_(0),
+      buffer_framebuffer_id_(0),
+      buffer_image_(nullptr) {}
+
+Compositor::RenderTarget::~RenderTarget() { Destroy(); }
+
+void Compositor::RenderTarget::Destroy() {
+  glDeleteFramebuffers(1, &buffer_framebuffer_id_);
+  glDeleteTextures(1, &buffer_texture_id_);
+  eglDestroyImageKHR(eglGetDisplay(EGL_DEFAULT_DISPLAY), buffer_image_);
+  buffer_texture_id_ = 0;
+  buffer_framebuffer_id_ = 0;
+  buffer_image_ = nullptr;
+}
+
+void Compositor::RenderTarget::Initialize(int width, int height) {
+  LOG_ALWAYS_FATAL_IF(buffer_texture_id_ || buffer_framebuffer_id_ ||
+                      buffer_image_);
+  constexpr int usage = GRALLOC_USAGE_HW_FB | GRALLOC_USAGE_HW_COMPOSER |
+                        GRALLOC_USAGE_HW_RENDER |
+                        GRALLOC_USAGE_QCOM_FRAMEBUFFER_COMPRESSION;
+  buffer_ = std::make_shared<IonBuffer>(width, height,
+                                        HAL_PIXEL_FORMAT_RGBA_8888, usage);
+
+  native_buffer_ = new NativeBuffer(buffer_);
+
+  buffer_image_ = eglCreateImageKHR(
+      eglGetDisplay(EGL_DEFAULT_DISPLAY), EGL_NO_CONTEXT,
+      EGL_NATIVE_BUFFER_ANDROID,
+      static_cast<ANativeWindowBuffer*>(native_buffer_.get()), nullptr);
+
+  glGenTextures(1, &buffer_texture_id_);
+  glBindTexture(GL_TEXTURE_2D, buffer_texture_id_);
+  CHECK_GL();
+
+  glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, buffer_image_);
+  CHECK_GL();
+
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  glBindTexture(GL_TEXTURE_2D, 0);
+
+  // Generate a framebuffer.
+  glGenFramebuffers(1, &buffer_framebuffer_id_);
+  glBindFramebuffer(GL_FRAMEBUFFER, buffer_framebuffer_id_);
+  CHECK_GL();
+
+  // Attach the color buffer
+  glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
+                         buffer_texture_id_, 0);
+  CHECK_GL();
+  GLenum result = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+  CHECK_GL();
+  if (result != GL_FRAMEBUFFER_COMPLETE) {
+    ALOGE("Framebuffer incomplete: %d", result);
+  }
+
+  // Clear the render target to black once. In direct render mode we never draw
+  // the corner pixels.
+  glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+  glClear(GL_COLOR_BUFFER_BIT);
+  glFlush();
+
+  glBindFramebuffer(GL_FRAMEBUFFER, 0);
+  CHECK_GL();
+}
+
+void Compositor::RenderTarget::BindFramebuffer() {
+  glBindFramebuffer(GL_FRAMEBUFFER, buffer_framebuffer_id_);
+}
+
+void Compositor::RenderTarget::DiscardColorAttachment() {
+  GLenum attachment = GL_COLOR_ATTACHMENT0;
+  glDiscardFramebufferEXT(GL_FRAMEBUFFER, 1, &attachment);
+  CHECK_GL();
+}
+
+class Compositor::RenderPoseBufferObject {
+ public:
+  RenderPoseBufferObject(LocalHandle&& render_pose_buffer_fd) {
+    // Create new pose tracking buffer for this surface.
+    glGenBuffers(1, &render_pose_buffer_object_);
+    glBindBuffer(GL_UNIFORM_BUFFER, render_pose_buffer_object_);
+    if (render_pose_buffer_fd) {
+      LOG_ALWAYS_FATAL_IF(!glBindSharedBufferQCOM);
+      if (glBindSharedBufferQCOM)
+        glBindSharedBufferQCOM(GL_UNIFORM_BUFFER,
+                               sizeof(DisplaySurfaceMetadata),
+                               render_pose_buffer_fd.Get());
+      else
+        ALOGE("Error: Missing gralloc buffer extension");
+      CHECK_GL();
+    }
+    glBindBuffer(GL_UNIFORM_BUFFER, 0);
+  }
+
+  ~RenderPoseBufferObject() { glDeleteBuffers(1, &render_pose_buffer_object_); }
+
+  GLuint object_id() const { return render_pose_buffer_object_; }
+
+ private:
+  // Render pose buffer object. This contains an array of poses that corresponds
+  // with the surface buffers.
+  GLuint render_pose_buffer_object_;
+
+  RenderPoseBufferObject(const RenderPoseBufferObject&) = delete;
+  void operator=(const RenderPoseBufferObject&) = delete;
+};
+
+HeadMountMetrics CreateDefaultHeadMountMetrics() {
+  const bool enable_distortion =
+      property_get_bool(kDisableLensDistortionProp, 0) == 0;
+  return enable_distortion ? CreateHeadMountMetrics()
+                           : CreateUndistortedHeadMountMetrics();
+}
+
+Compositor::Compositor()
+    : head_mount_metrics_(CreateDefaultHeadMountMetrics()),
+      display_(0),
+      config_(0),
+      surface_(0),
+      context_(0),
+      active_render_target_(0),
+      is_render_direct_(false),
+      compute_fbo_(0),
+      compute_fbo_texture_(0),
+      hmd_metrics_requires_update_(false),
+      eds_pose_capture_enabled_(false) {}
+
+Compositor::~Compositor() {}
+
+bool Compositor::Initialize(const DisplayMetrics& display_metrics) {
+  ATRACE_NAME("Compositor::Initialize");
+  if (!InitializeEGL())
+    return false;
+
+  display_metrics_ = display_metrics;
+  const int width = display_metrics_.GetSizePixels().x();
+  const int height = display_metrics_.GetSizePixels().y();
+
+  render_target_[0].Initialize(width, height);
+  render_target_[1].Initialize(width, height);
+
+  // EDS:
+  GpuProfiler::Get()->SetEnableGpuTracing(true);
+
+  eds_pose_capture_enabled_ = property_get_bool(kEnableEdsPoseSaveProp, 0) == 1;
+
+  CheckAndUpdateHeadMountMetrics(true);
+
+  debug_hud_.reset(new DebugHudView(*composite_hmd_.get()));
+  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+  return true;
+}
+
+void Compositor::UpdateHeadMountMetrics(
+    const HeadMountMetrics& head_mount_metrics) {
+  // Recalculating the mesh must be done in the draw loop, defer until then.
+  std::lock_guard<std::mutex> _lock(mutex_);
+  head_mount_metrics_ = head_mount_metrics;
+  hmd_metrics_requires_update_ = true;
+}
+
+void Compositor::CheckAndUpdateHeadMountMetrics(bool force_update) {
+  std::lock_guard<std::mutex> _lock(mutex_);
+  if (hmd_metrics_requires_update_ || force_update) {
+    hmd_metrics_requires_update_ = false;
+    composite_hmd_.reset(
+        new CompositeHmd(head_mount_metrics_, display_metrics_));
+    CHECK_GL();
+    eds_renderer_.reset(new DistortionRenderer(
+        *composite_hmd_.get(), display_metrics_.GetSizePixels(),
+        kDistortionMeshResolution, true, false, false, true, true));
+  }
+}
+
+bool Compositor::InitializeEGL() {
+  ATRACE_NAME("Compositor::InitializeEGL");
+  display_ = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+  if (!display_) {
+    ALOGE("Failed to get egl display\n");
+    return false;
+  }
+
+  eglInitialize(display_, nullptr, nullptr);
+
+  EGLint attribs[] = {
+      EGL_BUFFER_SIZE,
+      32,
+      EGL_ALPHA_SIZE,
+      0,
+      EGL_BLUE_SIZE,
+      8,
+      EGL_RED_SIZE,
+      8,
+      EGL_GREEN_SIZE,
+      8,
+      EGL_DEPTH_SIZE,
+      0,
+      EGL_SURFACE_TYPE,
+      EGL_WINDOW_BIT,
+      EGL_RENDERABLE_TYPE,
+      EGL_OPENGL_ES2_BIT,
+      EGL_NONE,
+  };
+
+  EGLint num_configs;
+  if (!eglChooseConfig(display_, attribs, &config_, 1, &num_configs)) {
+    ALOGE("Couldn't find config");
+    return false;
+  }
+
+  std::unique_ptr<DummyNativeWindow> window(new DummyNativeWindow());
+
+  surface_ = eglCreateWindowSurface(display_, config_, window.get(), nullptr);
+  if (surface_ == EGL_NO_SURFACE) {
+    ALOGE("Failed to create egl surface");
+    return false;
+  }
+  window.release();
+
+  EGLint context_attribs[] = {EGL_CONTEXT_MAJOR_VERSION,
+                              3,
+                              EGL_CONTEXT_MINOR_VERSION,
+                              1,
+                              EGL_CONTEXT_PRIORITY_LEVEL_IMG,
+                              EGL_CONTEXT_PRIORITY_HIGH_IMG,
+                              EGL_NONE};
+  context_ = eglCreateContext(display_, config_, nullptr, context_attribs);
+  if (!eglMakeCurrent(display_, surface_, surface_, context_)) {
+    ALOGE("Unable to create GLESv2 context");
+    return false;
+  }
+
+  load_gl_extensions();
+
+  glEnable(BINNING_CONTROL_HINT_QCOM);
+  glHint(BINNING_CONTROL_HINT_QCOM, RENDER_DIRECT_TO_FRAMEBUFFER_QCOM);
+  is_render_direct_ = true;
+  CHECK_GL();
+
+  // Initialize the placeholder 1x1 framebuffer that we bind during compute
+  // shader instances to avoid accesses to other framebuffers.
+  glGenFramebuffers(1, &compute_fbo_);
+  glGenTextures(1, &compute_fbo_texture_);
+  glBindFramebuffer(GL_FRAMEBUFFER, compute_fbo_);
+  glBindTexture(GL_TEXTURE_2D, compute_fbo_texture_);
+  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE,
+               nullptr);
+  glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
+                         compute_fbo_texture_, 0);
+  CHECK_GL();
+  CHECK_GL_FBO();
+  glBindTexture(GL_TEXTURE_2D, 0);
+  glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+  return true;
+}
+
+void Compositor::Shutdown() {
+  render_target_[0].Destroy();
+  render_target_[1].Destroy();
+  layers_.clear();
+  glDeleteFramebuffers(1, &compute_fbo_);
+  glDeleteTextures(1, &compute_fbo_texture_);
+
+  debug_hud_.reset();
+  eds_renderer_.reset();
+
+  if (context_) {
+    eglDestroyContext(display_, context_);
+    context_ = 0;
+  }
+
+  if (surface_ != EGL_NO_SURFACE) {
+    eglDestroySurface(display_, surface_);
+    surface_ = EGL_NO_SURFACE;
+  }
+}
+
+void Compositor::RemoveAllBuffers() { layers_.clear(); }
+
+void Compositor::UpdateSurfaces(
+    const std::vector<std::shared_ptr<DisplaySurface>>& surfaces) {
+  // Delete the removed surfaces.
+  layers_.erase(
+      std::remove_if(layers_.begin(), layers_.end(),
+                     [&surfaces](const AppFrame& layer) {
+                       for (const auto& surface : surfaces)
+                         if (surface->surface_id() == layer.surface_id())
+                           return false;
+                       return true;
+                     }),
+      layers_.end());
+  // New surfaces are added on-demand as buffers are posted.
+}
+
+Compositor::AppFrame::AppFrame()
+    : surface_id_(-1),
+      blur_(0.0f),
+      z_order_(0),
+      vertical_flip_(false),
+      enable_cac_(true),
+      render_buffer_index_(0) {}
+
+Compositor::AppFrame::~AppFrame() {}
+
+const Compositor::Texture* Compositor::AppFrame::GetGlTextureId(
+    EGLDisplay display, int index) {
+  auto buffer_consumer = buffer_.buffer();
+  if (!buffer_consumer) {
+    return nullptr;
+  }
+  auto texture_it = std::find_if(
+      textures_.begin(), textures_.end(),
+      [buffer_consumer, index](const std::shared_ptr<Texture>& t) {
+        return t->consumer() == buffer_consumer && t->index() == index;
+      });
+
+  if (texture_it != textures_.end()) {
+    return (*texture_it).get();
+  }
+
+  textures_.push_back(
+      std::make_shared<Texture>(buffer_consumer, display, index));
+  if (!textures_.back()->Initialize()) {
+    textures_.pop_back();
+    return nullptr;
+  }
+  return textures_.back().get();
+}
+
+bool Compositor::AppFrame::UpdateSurface(
+    const std::shared_ptr<DisplaySurface>& surface) {
+  int surface_id = surface->surface_id();
+  float blur = surface->manager_blur();
+  bool need_sort = false;
+  if (z_order_ != surface->layer_order()) {
+    need_sort = true;
+    z_order_ = surface->layer_order();
+  }
+
+  surface_id_ = surface_id;
+  if (!render_pose_buffer_object_) {
+    render_pose_buffer_object_.reset(
+        new RenderPoseBufferObject(surface->GetMetadataBufferFd()));
+  }
+
+  blur_ = blur;
+  vertical_flip_ =
+      !!(surface->flags() & DVR_DISPLAY_SURFACE_FLAGS_VERTICAL_FLIP);
+  enable_cac_ =
+      !(surface->flags() & DVR_DISPLAY_SURFACE_FLAGS_DISABLE_SYSTEM_CAC);
+
+  AcquiredBuffer skipped_buffer;
+  AcquiredBuffer buffer =
+      surface->AcquireNewestAvailableBuffer(&skipped_buffer);
+  if (!skipped_buffer.IsEmpty()) {
+    DebugHudData::data.SkipLayerFrame(z_order_);
+    ATRACE_NAME("DropToCatchUp");
+    ATRACE_ASYNC_END("BufferPost", skipped_buffer.buffer()->id());
+  }
+  if (!buffer.IsEmpty()) {
+    DebugHudData::data.AddLayerFrame(z_order_);
+    // Buffer was already ready, so we don't need to wait on the fence.
+    buffer.ClaimAcquireFence().Close();
+    ATRACE_ASYNC_END("BufferPost", buffer.buffer()->id());
+
+    render_buffer_index_ = surface->GetRenderBufferIndex(buffer.buffer()->id());
+
+#ifdef TRACE
+    const volatile DisplaySurfaceMetadata* data =
+        surface->GetMetadataBufferPtr();
+#endif
+    ALOGE_IF(TRACE, "read pose index %d %f %f", render_buffer_index_,
+             data->orientation[render_buffer_index_][0],
+             data->orientation[render_buffer_index_][1]);
+
+    // Move the new buffer over the old. AcquiredBuffer releases the old one.
+    buffer_ = std::move(buffer);
+  }
+  return need_sort;
+}
+
+void Compositor::AppFrame::UpdateVideoMeshSurface(
+    const std::shared_ptr<DisplaySurface>& surface) {
+  // Update |video_compositors_| with |video_surface|. Note that
+  // |UpdateVideoMeshSurface| should only be called on the PostThread before
+  // |DrawFrame| is called. Thus, no synchronization is required for
+  // |video_compositors_|.
+  if (!surface->video_mesh_surfaces_updated())
+    return;
+
+  // TODO(jwcai) The following loop handles adding new surfaces; video mesh
+  // removal logic shall be handled by listening to |OnChannelClose| event from
+  // DisplayService.
+  for (const auto& video_surface : surface->GetVideoMeshSurfaces()) {
+    // Here we assume number of |video_surface|s is relatively small, thus, the
+    // merge should be efficient enough.
+    auto video_compositor_it = std::find_if(
+        video_compositors_.begin(), video_compositors_.end(),
+        [video_surface](const std::shared_ptr<VideoCompositor>& c) {
+          return c->surface_id() == video_surface->surface_id();
+        });
+
+    if (video_compositor_it == video_compositors_.end()) {
+      // This video surface is new, create a new VideoCompositor.
+      video_compositors_.push_back(std::make_shared<VideoCompositor>(
+          video_surface, surface->GetMetadataBufferPtr()));
+    } else {
+      // There is a compositor in |video_compositors_| is already set up for
+      // this |video_surface|.
+      ALOGW("Duplicated video_mesh_surface: surface_id=%d",
+            video_surface->surface_id());
+    }
+  }
+}
+
+void Compositor::AppFrame::ResetBlurrers() { blurrers_.clear(); }
+
+void Compositor::AppFrame::AddBlurrer(Blur* blurrer) {
+  blurrers_.emplace_back(blurrer);
+}
+
+void Compositor::PostBuffer(const std::shared_ptr<DisplaySurface>& surface) {
+  int surface_id = surface->surface_id();
+
+  ALOGD_IF(TRACE, "Post surface %d", surface_id);
+
+  auto layer_it = std::find_if(layers_.begin(), layers_.end(),
+                               [surface_id](const AppFrame& frame) {
+                                 return frame.surface_id() == surface_id;
+                               });
+
+  bool need_sort = false;
+  if (layer_it == layers_.end()) {
+    layers_.push_back(AppFrame());
+    layer_it = layers_.end() - 1;
+    need_sort = true;
+  }
+
+  need_sort |= layer_it->UpdateSurface(surface);
+  layer_it->UpdateVideoMeshSurface(surface);
+
+  if (need_sort) {
+    std::stable_sort(layers_.begin(), layers_.end());
+  }
+}
+
+std::vector<uint8_t> Compositor::ReadLayerPixels(size_t index, int* width,
+                                                 int* height) {
+  if (index >= layers_.size()) {
+    return {};
+  }
+
+  const Texture* texture = layers_[index].GetGlTextureId(display_, 0);
+  if (!texture) {
+    return {};
+  }
+
+  *width = texture->size()[0];
+  *height = texture->size()[1];
+  return ReadTextureRGBA(texture->texture_id(), *width, *height);
+}
+
+std::vector<uint8_t> Compositor::ReadBufferPixels(const IonBuffer* buffer) {
+  android::sp<TemporaryNativeBuffer> native_buffer =
+      new TemporaryNativeBuffer(buffer);
+
+  // Finish to make sure the GL driver has completed drawing of prior FBOs.
+  // Since we are creating an EGL image here, the driver will not know that
+  // there is a dependency on earlier GL draws.
+  glFinish();
+
+  EGLImageKHR image = eglCreateImageKHR(
+      display_, EGL_NO_CONTEXT, EGL_NATIVE_BUFFER_ANDROID,
+      static_cast<ANativeWindowBuffer*>(native_buffer.get()), nullptr);
+  if (!image) {
+    ALOGE("Failed to create EGLImage\n");
+    return {};
+  }
+
+  GLuint texture_id;
+  glGenTextures(1, &texture_id);
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_2D, texture_id);
+  glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, image);
+
+  int width = buffer->width();
+  int height = buffer->height();
+  std::vector<uint8_t> data = ReadTextureRGBA(texture_id, width, height);
+
+  glBindTexture(GL_TEXTURE_2D, 0);
+  glDeleteTextures(1, &texture_id);
+  eglDestroyImageKHR(display_, image);
+  return data;
+}
+
+bool Compositor::DrawFrame(uint32_t target_vsync_count,
+                           LocalHandle* buffer_fence_fd) {
+  CheckAndUpdateHeadMountMetrics(false);
+
+  ATRACE_NAME("Compositor::DrawFrame");
+  GpuProfiler::Get()->PollGlTimerQueries();
+
+  if (buffer_fence_fd)
+    buffer_fence_fd->Close();
+
+  int num_layers = 0;
+  const int kMaxLayers = 4;
+  GLuint texture_id[2][kMaxLayers] = {{0}};
+  GLuint render_pose_buffer_id[kMaxLayers] = {0};
+  uint32_t render_buffer_index[kMaxLayers] = {0};
+  bool vertical_flip[kMaxLayers] = {false};
+  bool separate_eye_textures[kMaxLayers] = {false};
+  bool enable_cac[kMaxLayers] = {};
+  CHECK_GL();
+  for (auto& layer : layers_) {
+    if (!layer.buffer().buffer()) {
+      ATRACE_NAME("no_buffer");
+      continue;
+    }
+
+    // Extract surface parameters.
+    render_buffer_index[num_layers] = layer.render_buffer_index();
+    render_pose_buffer_id[num_layers] =
+        layer.render_pose_buffer_object()->object_id();
+    vertical_flip[num_layers] = layer.vertical_flip();
+    enable_cac[num_layers] =
+        head_mount_metrics_.supports_chromatic_aberration_correction() &&
+        layer.enable_cac();
+
+    // Extract per-eye textures. These may be separate or joined (atlased).
+    vec2i size(0, 0);
+    int view_count = layer.buffer().buffer()->slice_count();
+    ALOGE_IF(view_count > 2, "Error: more than 2 views not supported");
+    view_count = std::min(2, view_count);
+    separate_eye_textures[num_layers] = (view_count > 1);
+    bool is_missing_texture = false;
+    for (int eye = 0; eye < 2; ++eye) {
+      // If view_count is 1, each eye texture is the 0th.
+      int view_index = (view_count == 2) ? eye : 0;
+      const Texture* texture = layer.GetGlTextureId(display_, view_index);
+      // Texture will be null if the EGL image creation fails (hopefully never).
+      if (!texture) {
+        is_missing_texture = true;
+        break;
+      }
+      // All views are currently expected to have the same size.
+      size = texture->size();
+      texture_id[eye][num_layers] = texture->texture_id();
+    }
+    if (is_missing_texture) {
+      continue;
+    }
+
+    // Perform blur if requested.
+    if (fabs(layer.blur()) > 0.001f) {
+      // No need for CAC on blurred layers.
+      enable_cac[num_layers] = false;
+      if (layer.blurrer_count() < 1 || layer.blurrer(0)->width() != size[0] ||
+          layer.blurrer(0)->height() != size[1]) {
+        // Blur is created with the left eye texture, but the same instance
+        // can be used for the right eye as well.
+        layer.ResetBlurrers();
+        layer.AddBlurrer(new Blur(size[0], size[1], texture_id[0][num_layers],
+                                  GL_TEXTURE_2D, GL_TEXTURE_2D, true, display_,
+                                  view_count));
+      }
+      // Reset blur instances to prepare for drawing.
+      layer.blurrer(0)->StartFrame();
+      layer.blurrer(0)->set_scale(layer.blur());
+      // Perform blur and replace source texture with blurred output texture.
+      if (view_count == 1) {
+        // Single wide buffer for both eyes, blur both eyes in one operation.
+        texture_id[0][num_layers] = texture_id[1][num_layers] =
+            layer.blurrer(0)->DrawBlur(texture_id[0][num_layers]);
+      } else {
+        // Split eye buffers in a single frame, blur each framebuffer.
+        texture_id[0][num_layers] =
+            layer.blurrer(0)->DrawBlur(texture_id[0][num_layers]);
+        texture_id[1][num_layers] =
+            layer.blurrer(0)->DrawBlur(texture_id[1][num_layers]);
+      }
+    }
+
+    ++num_layers;
+    if (num_layers >= kMaxLayers)
+      break;
+  }
+
+  CHECK_GL();
+  // Set appropriate binning mode for the number of layers.
+  if (num_layers > 1 && is_render_direct_) {
+    is_render_direct_ = false;
+    glDisable(BINNING_CONTROL_HINT_QCOM);
+  } else if (num_layers <= 1 && !is_render_direct_) {
+    is_render_direct_ = true;
+    glEnable(BINNING_CONTROL_HINT_QCOM);
+    glHint(BINNING_CONTROL_HINT_QCOM, RENDER_DIRECT_TO_FRAMEBUFFER_QCOM);
+  }
+
+  // Workaround for GL driver bug that causes the currently bound FBO to be
+  // accessed during a compute shader pass (DoLateLatch below). Based on an
+  // analysis with systrace, the best pattern here was to run the compute shader
+  // with a *different* FBO than what will be drawn to afterward. So we bind
+  // a dummy 1x1 FBO here and discard it. If instead, the current render target
+  // is bound during the compute shader, the following draw calls will be forced
+  // into direct mode rendering.
+  glBindFramebuffer(GL_FRAMEBUFFER, compute_fbo_);
+  GLenum attachment = GL_COLOR_ATTACHMENT0;
+  glDiscardFramebufferEXT(GL_FRAMEBUFFER, 1, &attachment);
+
+  // Double buffer the render target.  Get the render target we're drawing into,
+  // and update the active buffer to the next buffer.
+  RenderTarget& render_target = GetRenderTarget();
+  SetNextRenderTarget();
+
+  if (num_layers > 0) {
+    // This trace prints the EDS+Warp GPU overhead and prints every 5 seconds:
+    TRACE_GPU_PRINT("GPU EDS+Warp", 5 * 60);
+    CHECK_GL();
+    eds_renderer_->DoLateLatch(target_vsync_count, render_buffer_index,
+                               render_pose_buffer_id, vertical_flip,
+                               separate_eye_textures, num_layers);
+
+    render_target.BindFramebuffer();
+
+    // Discard to avoid unresolving the framebuffer during tiled rendering.
+    render_target.DiscardColorAttachment();
+
+    // For tiled mode rendering, we clear every frame to avoid garbage showing
+    // up in the parts of tiles that are not rendered.
+    if (!is_render_direct_) {
+      glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+      glClear(GL_COLOR_BUFFER_BIT);
+    }
+
+    for (int eye = kLeftEye; eye <= kRightEye; ++eye) {
+      eds_renderer_->PrepGlState(static_cast<EyeType>(eye));
+      for (int layer_i = 0; layer_i < num_layers; ++layer_i) {
+        bool blend_with_previous = layer_i > 0;
+        uint32_t current_buffer_index = render_buffer_index[layer_i];
+
+        // Render video mesh in the background of each graphics layer.
+        layers_[layer_i].ForEachVideoCompositor([this, eye, layer_i,
+                                                 current_buffer_index,
+                                                 &blend_with_previous](
+            const std::shared_ptr<VideoCompositor>& video_compositor) mutable {
+          eds_renderer_->DrawVideoQuad(
+              static_cast<EyeType>(eye), layer_i,
+              video_compositor->GetActiveTextureId(display_),
+              video_compositor->GetTransform(eye, current_buffer_index));
+          blend_with_previous = true;
+        });
+
+        // Apply distortion to frame submitted from the app's GL context.
+        eds_renderer_->SetChromaticAberrationCorrectionEnabled(
+            enable_cac[layer_i]);
+        eds_renderer_->ApplyDistortionCorrectionToTexture(
+            static_cast<EyeType>(eye), &texture_id[eye][layer_i],
+            &vertical_flip[layer_i], &separate_eye_textures[layer_i], &layer_i,
+            1, blend_with_previous, false);
+      }
+    }
+    eds_renderer_->ResetGlState(1);
+    CHECK_GL();
+  } else {
+    ALOGI("No buffers for compositing, clearing to black.");
+    render_target.BindFramebuffer();
+    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+    glClear(GL_COLOR_BUFFER_BIT);
+  }
+
+  debug_hud_->Update();
+  debug_hud_->Draw();
+
+  LocalHandle fence_fd = CreateGLSyncAndFlush(display_);
+
+  if (buffer_fence_fd)
+    *buffer_fence_fd = std::move(fence_fd);
+
+  if (eds_pose_capture_enabled_) {
+    std::lock_guard<std::mutex> _lock(mutex_);
+    eds_renderer_->GetLastEdsPose(&eds_pose_capture_);
+  }
+
+  return true;
+}
+
+bool Compositor::GetLastEdsPose(LateLatchOutput* out_data) {
+  if (eds_pose_capture_enabled_) {
+    std::lock_guard<std::mutex> _lock(mutex_);
+    *out_data = eds_pose_capture_;
+    return true;
+  } else {
+    ALOGE("Eds pose capture is not enabled.");
+    return false;
+  }
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/compositor.h b/libs/vr/libvrflinger/compositor.h
new file mode 100644
index 0000000..be26d31
--- /dev/null
+++ b/libs/vr/libvrflinger/compositor.h
@@ -0,0 +1,233 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_COMPOSITOR_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_COMPOSITOR_H_
+
+#include <EGL/egl.h>
+#include <log/log.h>
+#include <utils/StrongPointer.h>
+
+#include <memory>
+#include <mutex>
+#include <queue>
+#include <vector>
+
+#include <pdx/file_handle.h>
+#include <private/dvr/clock_ns.h>
+#include <private/dvr/composite_hmd.h>
+#include <private/dvr/display_metrics.h>
+#include <private/dvr/distortion_renderer.h>
+#include <private/dvr/frame_time_history.h>
+#include <private/dvr/ion_buffer.h>
+#include <private/dvr/native_buffer.h>
+
+#include "acquired_buffer.h"
+#include "video_compositor.h"
+struct DvrPose;
+
+namespace android {
+namespace dvr {
+
+class Blur;
+class BufferConsumer;
+class CompositeHmd;
+class DebugHudView;
+class DisplaySurface;
+
+// This is a GPU compositor for software EDS and lens warp on buffers provided
+// by HardwareComposer.
+class Compositor {
+ public:
+  Compositor();
+  ~Compositor();
+
+  bool Initialize(const DisplayMetrics& display_metrics);
+  void UpdateHeadMountMetrics(const HeadMountMetrics& head_mount_metrics);
+  void Shutdown();
+
+  // Renders a frame with the latest buffers with EDS and warp applied.
+  // buffer_fence_fd can be used to get a fence for the rendered frame. It can
+  // be set to null if the fence isn't needed.
+  bool DrawFrame(uint32_t target_vsync_count,
+                 pdx::LocalHandle* buffer_fence_fd);
+
+  // Remove all buffers.
+  void RemoveAllBuffers();
+
+  // Synchronize compositor layers with in given surfaces.
+  void UpdateSurfaces(
+      const std::vector<std::shared_ptr<DisplaySurface>>& surfaces);
+
+  // This must be called for each surface before DrawFrame is called.
+  void PostBuffer(const std::shared_ptr<DisplaySurface>& surface);
+
+  std::shared_ptr<IonBuffer> GetBuffer() const {
+    return render_target_[active_render_target_].buffer();
+  }
+
+  // Returns the number of layers being rendered by the compositor.
+  size_t GetLayerCount() const { return layers_.size(); }
+
+  // Returns the source buffer at the given layer index or nullptr if none is
+  // available.
+  std::shared_ptr<BufferConsumer> PeekAtLayer(size_t index) const {
+    if (index >= GetLayerCount())
+      return nullptr;
+    return layers_[index].buffer().buffer();
+  }
+
+  // Expensive operation to transfer the pixels of the given layer index into
+  // unformatted memory and return as a RGBA buffer.
+  // On success, returns non-zero sized vector and sets width and height.
+  // On failure, returns empty vector.
+  std::vector<uint8_t> ReadLayerPixels(size_t index, int* width, int* height);
+
+  // Expensive operation to transfer the pixels of the given buffer into
+  // unformatted memory and return as a RGBA buffer.
+  // On success, returns non-zero sized vector.
+  // On failure, returns empty vector.
+  std::vector<uint8_t> ReadBufferPixels(const IonBuffer* buffer);
+
+  bool GetLastEdsPose(LateLatchOutput* out_data);
+
+  const HeadMountMetrics& head_mount_metrics() const {
+    return head_mount_metrics_;
+  }
+
+ private:
+  class Texture;
+  class RenderPoseBufferObject;
+
+  // A rendered frame from an application.
+  class AppFrame {
+   public:
+    AppFrame();
+    ~AppFrame();
+
+    AppFrame(AppFrame&& other) = default;
+    AppFrame& operator=(AppFrame&&) = default;
+
+    // Gets a GL texture object for the current buffer. The resulting texture
+    // object will be cached for future calls. Returns a pointer for temporary
+    // access - not meant to hold on to.
+    const Texture* GetGlTextureId(EGLDisplay display, int index);
+
+    bool operator<(const AppFrame& rhs) const {
+      return z_order_ < rhs.z_order_;
+    }
+    int z_order() const { return z_order_; }
+    // Return true if this surface z order has been changed.
+    bool UpdateSurface(const std::shared_ptr<DisplaySurface>& surface);
+    void UpdateVideoMeshSurface(const std::shared_ptr<DisplaySurface>& surface);
+    void ResetBlurrers();
+    void AddBlurrer(Blur* blurrer);
+
+    const AcquiredBuffer& buffer() const { return buffer_; }
+    int surface_id() const { return surface_id_; }
+    float blur() const { return blur_; }
+    bool vertical_flip() const { return vertical_flip_; }
+    bool enable_cac() const { return enable_cac_; }
+    size_t blurrer_count() const { return blurrers_.size(); }
+    Blur* blurrer(size_t i) {
+      return blurrers_.size() < i ? nullptr : blurrers_[i].get();
+    }
+    uint32_t render_buffer_index() const { return render_buffer_index_; }
+    const RenderPoseBufferObject* render_pose_buffer_object() const {
+      return render_pose_buffer_object_.get();
+    }
+
+    template <class A>
+    void ForEachVideoCompositor(A action) const {
+      for (auto& c : video_compositors_) {
+        action(c);
+      }
+    }
+
+   private:
+    int surface_id_;
+    float blur_;
+    int z_order_;
+    bool vertical_flip_;
+    bool enable_cac_;
+    std::vector<std::unique_ptr<Blur>> blurrers_;
+    AcquiredBuffer buffer_;
+    std::vector<std::shared_ptr<Texture>> textures_;
+    uint32_t render_buffer_index_;
+    std::unique_ptr<RenderPoseBufferObject> render_pose_buffer_object_;
+
+    // Active video mesh compositors
+    std::vector<std::shared_ptr<VideoCompositor>> video_compositors_;
+
+    AppFrame(const AppFrame& other) = delete;
+    AppFrame& operator=(const AppFrame&) = delete;
+  };
+
+  class RenderTarget {
+   public:
+    RenderTarget();
+    ~RenderTarget();
+
+    void Initialize(int width, int height);
+    void Destroy();
+    void BindFramebuffer();
+    void DiscardColorAttachment();
+
+    std::shared_ptr<IonBuffer> buffer() const { return buffer_; }
+
+   private:
+    std::shared_ptr<IonBuffer> buffer_;
+    android::sp<NativeBuffer> native_buffer_;
+
+    GLuint buffer_texture_id_;
+    GLuint buffer_framebuffer_id_;
+    EGLImageKHR buffer_image_;
+  };
+
+  Compositor(const Compositor&) = delete;
+  void operator=(const Compositor&) = delete;
+
+  bool InitializeEGL();
+
+  void UpdateHudToggle();
+  void PrintStatsHud();
+  void CheckAndUpdateHeadMountMetrics(bool force_update);
+
+  RenderTarget& GetRenderTarget() {
+    return render_target_[active_render_target_];
+  }
+
+  void SetNextRenderTarget() {
+    active_render_target_ = (active_render_target_ + 1) & 1;
+  }
+
+  std::vector<AppFrame> layers_;
+
+  DisplayMetrics display_metrics_;
+  HeadMountMetrics head_mount_metrics_;
+
+  EGLDisplay display_;
+  EGLConfig config_;
+  EGLSurface surface_;
+  EGLContext context_;
+  int active_render_target_;
+  RenderTarget render_target_[2];
+  bool is_render_direct_;
+
+  // FBO for compute shader.
+  GLuint compute_fbo_;
+  GLuint compute_fbo_texture_;
+
+  std::unique_ptr<DebugHudView> debug_hud_;
+
+  // EDS:
+  std::unique_ptr<CompositeHmd> composite_hmd_;
+  bool hmd_metrics_requires_update_;
+  std::unique_ptr<DistortionRenderer> eds_renderer_;
+
+  bool eds_pose_capture_enabled_;
+  std::mutex mutex_;
+  LateLatchOutput eds_pose_capture_;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_COMPOSITOR_H_
diff --git a/libs/vr/libvrflinger/debug_hud_data.cpp b/libs/vr/libvrflinger/debug_hud_data.cpp
new file mode 100644
index 0000000..d387bba
--- /dev/null
+++ b/libs/vr/libvrflinger/debug_hud_data.cpp
@@ -0,0 +1,9 @@
+#include "debug_hud_data.h"
+
+namespace android {
+namespace dvr {
+
+DebugHudData DebugHudData::data;
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/debug_hud_data.h b/libs/vr/libvrflinger/debug_hud_data.h
new file mode 100644
index 0000000..778169d
--- /dev/null
+++ b/libs/vr/libvrflinger/debug_hud_data.h
@@ -0,0 +1,110 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_DEBUG_HUD_DATA_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_DEBUG_HUD_DATA_H_
+
+#include <stdint.h>
+
+#include <private/dvr/clock_ns.h>
+#include <private/dvr/frame_time_history.h>
+
+namespace android {
+namespace dvr {
+
+// Tracks debug stats for the displayd debug HUD. Unless otherwise noted,
+// there is no synchronization of data accesses to avoid performance impact.
+// All accesses to this data are on the displayd HWC post thread. Accesses from
+// other threads will need to be duly protected from races.
+// This is a lightweight struct to make it easy to add and remove
+// tracking data.
+struct DebugHudData {
+  // Maximum supported layers for the debug HUD.
+  enum { kMaxLayers = 4 };
+
+  // The global singleton HUD data instance.
+  static DebugHudData data;
+
+  // Tracks framerate and skipped frames.
+  struct FrameStats {
+    void AddFrame() {
+      int64_t now = GetSystemClockNs();
+      frame_time.AddSample(now - last_frame_ts);
+      last_frame_ts = now;
+    }
+
+    void SkipFrame() {
+      AddFrame();
+      ++drops;
+    }
+
+    int drops = 0;
+    int64_t last_frame_ts = 0;
+    FrameTimeHistory frame_time;
+  };
+
+  // Debug data for compositor layers (applications, system UI, etc).
+  struct LayerData {
+    void Reset() {
+      ResetStats();
+      width = 0;
+      height = 0;
+      is_separate = false;
+    }
+
+    void ResetStats() { frame_stats.drops = 0; }
+
+    FrameStats frame_stats;
+    int width = 0;
+    int height = 0;
+    bool is_separate = false;
+  };
+
+  // Resets the stats.
+  void ResetStats() {
+    hwc_frame_stats.drops = 0;
+    hwc_latency = 0;
+    for (auto& l : layer_data)
+      l.ResetStats();
+  }
+
+  // Resets the layer configuration.
+  void ResetLayers() {
+    num_layers = 0;
+    for (auto& l : layer_data)
+      l.Reset();
+  }
+
+  // Tracks a frame arrival for the given layer.
+  void AddLayerFrame(size_t layer) {
+    if (layer < kMaxLayers) {
+      num_layers = std::max(layer + 1, num_layers);
+      layer_data[layer].frame_stats.AddFrame();
+    }
+  }
+
+  // Tracks a frame skip/drop for the given layer.
+  void SkipLayerFrame(size_t layer) {
+    if (layer < kMaxLayers) {
+      num_layers = std::max(layer + 1, num_layers);
+      layer_data[layer].frame_stats.SkipFrame();
+    }
+  }
+
+  // Sets the resolution and other details of the layer.
+  void SetLayerInfo(size_t layer, int width, int height, bool is_separate) {
+    if (layer < kMaxLayers) {
+      num_layers = std::max(layer + 1, num_layers);
+      layer_data[layer].width = width;
+      layer_data[layer].height = height;
+      layer_data[layer].is_separate = is_separate;
+    }
+  }
+
+  FrameStats hwc_frame_stats;
+  int64_t hwc_latency = 0;
+  size_t num_layers = 0;
+  LayerData layer_data[kMaxLayers];
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_DEBUG_HUD_DATA_H_
diff --git a/libs/vr/libvrflinger/debug_hud_view.cpp b/libs/vr/libvrflinger/debug_hud_view.cpp
new file mode 100644
index 0000000..4936ac6
--- /dev/null
+++ b/libs/vr/libvrflinger/debug_hud_view.cpp
@@ -0,0 +1,91 @@
+#include "debug_hud_view.h"
+
+#include <dvr/pose_client.h>
+
+#include "debug_hud_data.h"
+
+namespace android {
+namespace dvr {
+
+DebugHudView::DebugHudView(const CompositeHmd& hmd) {
+  pose_client_ = dvrPoseCreate();
+
+  display_size_ = hmd.GetDisplayMetrics().GetSizePixels();
+  vec2 display_size_meters = hmd.GetDisplayMetrics().GetSizeMeters();
+  inter_lens_dist_screen_space_ =
+      2.0f * hmd.GetHeadMountMetrics().GetInterLensDistance() /
+      std::max(display_size_meters[0], display_size_meters[1]);
+}
+
+DebugHudView::~DebugHudView() {
+  if (pose_client_)
+    dvrPoseDestroy(pose_client_);
+  pose_client_ = nullptr;
+}
+
+void DebugHudView::Update() {
+  // Check for gesture that enables the debug stats HUD.
+  if (!pose_client_)
+    return;
+  DvrPoseAsync pose;
+  dvrPoseGet(pose_client_, 0, &pose);
+  float32x4_t q = pose.orientation;
+  quat orientation(q[3], q[0], q[1], q[2]);
+  vec3 up = orientation * vec3(0, 1, 0);
+  if (up[1] < -0.8f) {
+    ++switch_timer_;
+  } else {
+    switch_timer_ = 0;
+  }
+  // A few seconds upside down => toggle stats HUD.
+  if (switch_timer_ > 200) {
+    switch_timer_ = 0;
+    enabled_ = !enabled_;
+    DebugHudData::data.ResetStats();
+    ALOGE("Toggle debug stats HUD: %s", enabled_ ? "ON" : "OFF");
+  }
+}
+
+void DebugHudView::Draw() {
+  if (!enabled_)
+    return;
+  if (!debug_text_)
+    debug_text_.reset(new DebugText(400, display_size_[0], display_size_[1]));
+
+  const DebugHudData& data = DebugHudData::data;
+  const size_t layer_char_count = 50;
+  char layer_data[DebugHudData::kMaxLayers][layer_char_count];
+  for (size_t i = 0; i < data.num_layers; ++i) {
+    float fps = data.layer_data[i].frame_stats.frame_time.GetAverageFps();
+    snprintf(layer_data[i], layer_char_count,
+             "Layer %d %dx%d%s FPS: %.2f Drops: %d\n", static_cast<int>(i),
+             data.layer_data[i].width, data.layer_data[i].height,
+             data.layer_data[i].is_separate ? "x2" : "", fps,
+             data.layer_data[i].frame_stats.drops);
+  }
+
+  float hwc_fps = data.hwc_frame_stats.frame_time.GetAverageFps();
+
+  char text[400];
+  float hwc_latency_ms = static_cast<float>(data.hwc_latency) / 1000000.0f;
+  snprintf(text, sizeof(text), "HWC FPS: %.2f Latency: %.3f ms Skips: %d\n",
+           hwc_fps, hwc_latency_ms, data.hwc_frame_stats.drops);
+
+  for (size_t i = 0; i < data.num_layers; ++i) {
+    strncat(text, layer_data[i], sizeof(text) - strlen(text) - 1);
+  }
+
+  // Ensure text termination.
+  text[sizeof(text) - 1] = '\0';
+
+  glViewport(0, 0, display_size_[0], display_size_[1]);
+  glEnable(GL_BLEND);
+  // No stereo, because you can see the HUD OK in one eye. Stereo actually
+  // makes it more difficult to focus sometimes. To enable stereo:
+  // replace the second to last parameter with inter_lens_dist_screen_space_.
+  debug_text_->Draw(0.0f, -0.7f * inter_lens_dist_screen_space_, text, 0.0f, 1);
+  glDisable(GL_BLEND);
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/debug_hud_view.h b/libs/vr/libvrflinger/debug_hud_view.h
new file mode 100644
index 0000000..50f38a8
--- /dev/null
+++ b/libs/vr/libvrflinger/debug_hud_view.h
@@ -0,0 +1,48 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_DEBUG_HUD_VIEW_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_DEBUG_HUD_VIEW_H_
+
+#include <stdint.h>
+
+#include <utils/Log.h>
+
+#include <private/dvr/composite_hmd.h>
+#include <private/dvr/graphics/debug_text.h>
+
+struct DvrPose;
+
+namespace android {
+namespace dvr {
+
+class CompositeHmd;
+
+// The view and the controller for the displayd debug HUD.
+// The HUD is enabled and disabled by internally tracking the head pose.
+// When the head pose is upside down for ~3 seconds, the enabled state toggles.
+// See DebugHudData for the data that is reported.
+class DebugHudView {
+ public:
+  DebugHudView(const CompositeHmd& hmd);
+  ~DebugHudView();
+
+  // Updates HUD state.
+  void Update();
+
+  // Draws HUD into the current framebuffer if it is currently enabled.
+  void Draw();
+
+ private:
+  DebugHudView(const DebugHudView&) = delete;
+  DebugHudView& operator=(const DebugHudView&) = delete;
+
+  DvrPose* pose_client_ = nullptr;
+  vec2i display_size_;
+  bool enabled_ = false;
+  int switch_timer_ = 0;
+  float inter_lens_dist_screen_space_ = 0.0f;
+  std::unique_ptr<DebugText> debug_text_;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_DEBUG_HUD_VIEW_H_
diff --git a/libs/vr/libvrflinger/display_manager_service.cpp b/libs/vr/libvrflinger/display_manager_service.cpp
new file mode 100644
index 0000000..6730ba8
--- /dev/null
+++ b/libs/vr/libvrflinger/display_manager_service.cpp
@@ -0,0 +1,225 @@
+#include "display_manager_service.h"
+
+#include <pdx/channel_handle.h>
+#include <pdx/default_transport/service_endpoint.h>
+#include <private/dvr/display_rpc.h>
+#include <sys/poll.h>
+
+#include <array>
+
+using android::pdx::Channel;
+using android::pdx::LocalChannelHandle;
+using android::pdx::Message;
+using android::pdx::default_transport::Endpoint;
+using android::pdx::rpc::DispatchRemoteMethod;
+using android::pdx::rpc::IfAnyOf;
+
+namespace {
+
+// As a first line of defense, the display manager endpoint is only accessible
+// to the user and group.
+
+// TODO(dnicoara): Remove read/write permission for others. This is in here just
+// to allow us to experiment with cast functionality from a plain old app.
+constexpr mode_t kDisplayManagerEndpointFileMode =
+    S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
+
+constexpr size_t kMaxSurfacesPerRequest = 32;
+
+}  // anonymous namespace
+
+namespace android {
+namespace dvr {
+
+void DisplayManager::SetNotificationsPending(bool pending) {
+  int ret = service_->ModifyChannelEvents(channel_id_, pending ? 0 : POLLIN,
+                                          pending ? POLLIN : 0);
+  ALOGE_IF(ret < 0,
+           "DisplayManager::SetNotificationPending: Failed to modify channel "
+           "events: %s",
+           strerror(-ret));
+}
+
+DisplayManagerService::DisplayManagerService(
+    const std::shared_ptr<DisplayService>& display_service)
+    : BASE("DisplayManagerService",
+           Endpoint::Create(DisplayManagerRPC::kClientPath,
+                            kDisplayManagerEndpointFileMode)),
+      display_service_(display_service) {
+  display_service_->SetDisplayConfigurationUpdateNotifier(
+      std::bind(&DisplayManagerService::OnDisplaySurfaceChange, this));
+}
+
+std::shared_ptr<pdx::Channel> DisplayManagerService::OnChannelOpen(
+    pdx::Message& message) {
+  // Prevent more than one display manager from registering at a time.
+  if (display_manager_)
+    REPLY_ERROR_RETURN(message, EPERM, nullptr);
+
+  display_manager_ =
+      std::make_shared<DisplayManager>(this, message.GetChannelId());
+  return display_manager_;
+}
+
+void DisplayManagerService::OnChannelClose(
+    pdx::Message& /*message*/, const std::shared_ptr<pdx::Channel>& channel) {
+  // Unregister the display manager when the channel closes.
+  if (display_manager_ == channel)
+    display_manager_ = nullptr;
+}
+
+int DisplayManagerService::HandleMessage(pdx::Message& message) {
+  auto channel = std::static_pointer_cast<DisplayManager>(message.GetChannel());
+
+  switch (message.GetOp()) {
+    case DisplayManagerRPC::GetSurfaceList::Opcode:
+      DispatchRemoteMethod<DisplayManagerRPC::GetSurfaceList>(
+          *this, &DisplayManagerService::OnGetSurfaceList, message);
+      return 0;
+
+    case DisplayManagerRPC::GetSurfaceBuffers::Opcode:
+      DispatchRemoteMethod<DisplayManagerRPC::GetSurfaceBuffers>(
+          *this, &DisplayManagerService::OnGetSurfaceBuffers, message);
+      return 0;
+
+    case DisplayManagerRPC::UpdateSurfaces::Opcode:
+      DispatchRemoteMethod<DisplayManagerRPC::UpdateSurfaces>(
+          *this, &DisplayManagerService::OnUpdateSurfaces, message);
+      return 0;
+
+    default:
+      return Service::DefaultHandleMessage(message);
+  }
+}
+
+std::vector<DisplaySurfaceInfo> DisplayManagerService::OnGetSurfaceList(
+    pdx::Message& /*message*/) {
+  std::vector<DisplaySurfaceInfo> items;
+
+  display_service_->ForEachDisplaySurface([&items](
+      const std::shared_ptr<DisplaySurface>& surface) mutable {
+    DisplaySurfaceInfo item;
+
+    item.surface_id = surface->surface_id();
+    item.process_id = surface->process_id();
+    item.type = surface->type();
+    item.flags = 0;  // TODO(eieio)
+    item.client_attributes = DisplaySurfaceAttributes{
+        {DisplaySurfaceAttributeEnum::Visible,
+         DisplaySurfaceAttributeValue{surface->client_visible()}},
+        {DisplaySurfaceAttributeEnum::ZOrder,
+         DisplaySurfaceAttributeValue{surface->client_z_order()}},
+        {DisplaySurfaceAttributeEnum::Blur, DisplaySurfaceAttributeValue{0.f}}};
+    item.manager_attributes = DisplaySurfaceAttributes{
+        {DisplaySurfaceAttributeEnum::Visible,
+         DisplaySurfaceAttributeValue{surface->manager_visible()}},
+        {DisplaySurfaceAttributeEnum::ZOrder,
+         DisplaySurfaceAttributeValue{surface->manager_z_order()}},
+        {DisplaySurfaceAttributeEnum::Blur,
+         DisplaySurfaceAttributeValue{surface->manager_blur()}}};
+
+    items.push_back(item);
+  });
+
+  // The fact that we're in the message handler implies that display_manager_ is
+  // not nullptr. No check required, unless this service becomes multi-threaded.
+  display_manager_->SetNotificationsPending(false);
+
+  return items;
+}
+
+std::vector<LocalChannelHandle> DisplayManagerService::OnGetSurfaceBuffers(
+    pdx::Message& message, int surface_id) {
+  std::shared_ptr<DisplaySurface> surface =
+      display_service_->GetDisplaySurface(surface_id);
+  if (!surface)
+    REPLY_ERROR_RETURN(message, ENOENT, {});
+
+  std::vector<LocalChannelHandle> consumers;
+  int ret = surface->GetConsumers(&consumers);
+  if (ret < 0) {
+    ALOGE(
+        "DisplayManagerService::OnGetDisplaySurfaceBuffers: Failed to get "
+        "consumers for surface %d: %s",
+        surface_id, strerror(-ret));
+    REPLY_ERROR_RETURN(message, -ret, {});
+  }
+
+  return consumers;
+}
+
+int DisplayManagerService::OnUpdateSurfaces(
+    pdx::Message& /*message*/,
+    const std::map<int, DisplaySurfaceAttributes>& updates) {
+  for (const auto& surface_update : updates) {
+    const int surface_id = surface_update.first;
+    const DisplaySurfaceAttributes& attributes = surface_update.second;
+
+    std::shared_ptr<DisplaySurface> surface =
+        display_service_->GetDisplaySurface(surface_id);
+
+    if (!surface)
+      return -ENOENT;
+
+    for (const auto& attribute : attributes) {
+      const auto& key = attribute.first;
+      const auto* variant = &attribute.second;
+      bool invalid_value = false;
+      switch (key) {
+        case DisplaySurfaceAttributeEnum::ZOrder:
+          invalid_value =
+              !IfAnyOf<int32_t>::Call(variant, [&surface](const auto& value) {
+                surface->ManagerSetZOrder(value);
+              });
+          break;
+        case DisplaySurfaceAttributeEnum::Visible:
+          invalid_value = !IfAnyOf<int32_t, int64_t, bool>::Call(
+              variant, [&surface](const auto& value) {
+                surface->ManagerSetVisible(value);
+              });
+          break;
+        case DisplaySurfaceAttributeEnum::Blur:
+          invalid_value = !IfAnyOf<int32_t, int64_t, float>::Call(
+              variant, [&surface](const auto& value) {
+                surface->ManagerSetBlur(value);
+              });
+          break;
+        default:
+          ALOGW(
+              "DisplayManagerService::OnUpdateSurfaces: Attempt to set invalid "
+              "attribute %u on surface %d",
+              key, surface_id);
+          break;
+      }
+
+      if (invalid_value) {
+        ALOGW(
+            "DisplayManagerService::OnUpdateSurfaces: Failed to set display "
+            "surface attribute '%s' because of incompatible type: %d",
+            DisplaySurfaceAttributeEnum::ToString(key).c_str(),
+            variant->index());
+      }
+    }
+  }
+
+  // Reconfigure the display layers for any active surface changes.
+  display_service_->UpdateActiveDisplaySurfaces();
+  return 0;
+}
+
+void DisplayManagerService::OnDisplaySurfaceChange() {
+  if (display_manager_) {
+    display_manager_->SetNotificationsPending(true);
+  } else {
+    // If there isn't a display manager registered, default all display surfaces
+    // to visible.
+    display_service_->ForEachDisplaySurface(
+        [](const std::shared_ptr<DisplaySurface>& surface) {
+          surface->ManagerSetVisible(true);
+        });
+    display_service_->UpdateActiveDisplaySurfaces();
+  }
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/display_manager_service.h b/libs/vr/libvrflinger/display_manager_service.h
new file mode 100644
index 0000000..46401fa
--- /dev/null
+++ b/libs/vr/libvrflinger/display_manager_service.h
@@ -0,0 +1,73 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_DISPLAY_MANAGER_SERVICE_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_DISPLAY_MANAGER_SERVICE_H_
+
+#include <pdx/service.h>
+#include <private/dvr/display_rpc.h>
+
+#include "display_service.h"
+
+namespace android {
+namespace dvr {
+
+class DisplayManagerService;
+
+// The display manager is a client of the display manager service. This class
+// represents the connected client that the display manager service sends
+// notifications to.
+class DisplayManager : public pdx::Channel {
+ public:
+  DisplayManager(DisplayManagerService* service, int channel_id)
+      : service_(service), channel_id_(channel_id) {}
+
+  int channel_id() const { return channel_id_; }
+
+  // Sets or clears the channel event mask to indicate pending events that the
+  // display manager on the other end of the channel should read and handle.
+  // When |pending| is true the POLLIN bit is set in the event mask; when
+  // |pending| is false the POLLIN bit is cleared in the event mask.
+  void SetNotificationsPending(bool pending);
+
+ private:
+  DisplayManager(const DisplayManager&) = delete;
+  void operator=(const DisplayManager&) = delete;
+
+  DisplayManagerService* service_;
+  int channel_id_;
+};
+
+// The display manager service marshalls state and events from the display
+// service to the display manager.
+class DisplayManagerService : public pdx::ServiceBase<DisplayManagerService> {
+ public:
+  std::shared_ptr<pdx::Channel> OnChannelOpen(pdx::Message& message) override;
+  void OnChannelClose(pdx::Message& message,
+                      const std::shared_ptr<pdx::Channel>& channel) override;
+  int HandleMessage(pdx::Message& message) override;
+
+ private:
+  friend BASE;
+
+  explicit DisplayManagerService(
+      const std::shared_ptr<DisplayService>& display_service);
+
+  std::vector<DisplaySurfaceInfo> OnGetSurfaceList(pdx::Message& message);
+  std::vector<pdx::LocalChannelHandle> OnGetSurfaceBuffers(
+      pdx::Message& message, int surface_id);
+  int OnUpdateSurfaces(pdx::Message& message,
+                       const std::map<int, DisplaySurfaceAttributes>& updates);
+
+  // Called by the display service to indicate changes to display surfaces that
+  // the display manager should evaluate.
+  void OnDisplaySurfaceChange();
+
+  DisplayManagerService(const DisplayManagerService&) = delete;
+  void operator=(const DisplayManagerService&) = delete;
+
+  std::shared_ptr<DisplayService> display_service_;
+  std::shared_ptr<DisplayManager> display_manager_;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_DISPLAY_MANAGER_SERVICE_H_
diff --git a/libs/vr/libvrflinger/display_service.cpp b/libs/vr/libvrflinger/display_service.cpp
new file mode 100644
index 0000000..c464c98
--- /dev/null
+++ b/libs/vr/libvrflinger/display_service.cpp
@@ -0,0 +1,332 @@
+#include "display_service.h"
+
+#include <vector>
+
+#include <pdx/default_transport/service_endpoint.h>
+#include <pdx/rpc/remote_method.h>
+#include <private/dvr/composite_hmd.h>
+#include <private/dvr/display_rpc.h>
+#include <private/dvr/display_types.h>
+#include <private/dvr/lucid_metrics.h>
+#include <private/dvr/numeric.h>
+#include <private/dvr/polynomial_radial_distortion.h>
+#include <private/dvr/types.h>
+
+using android::pdx::Channel;
+using android::pdx::Message;
+using android::pdx::default_transport::Endpoint;
+using android::pdx::rpc::DispatchRemoteMethod;
+using android::pdx::rpc::WrapBuffer;
+
+namespace android {
+namespace dvr {
+
+DisplayService::DisplayService() : DisplayService(nullptr) {}
+
+DisplayService::DisplayService(Hwc2::Composer* hidl)
+    : BASE("DisplayService", Endpoint::Create(DisplayRPC::kClientPath)),
+      hardware_composer_(hidl) {}
+
+std::string DisplayService::DumpState(size_t max_length) {
+  std::vector<char> buffer(max_length);
+  uint32_t max_len_p = static_cast<uint32_t>(max_length);
+  hardware_composer_.Dump(buffer.data(), &max_len_p);
+  return std::string(buffer.data());
+}
+
+void DisplayService::OnChannelClose(pdx::Message& /*message*/,
+                                    const std::shared_ptr<Channel>& channel) {
+  auto surface = std::static_pointer_cast<SurfaceChannel>(channel);
+  if (surface && surface->type() == SurfaceTypeEnum::Normal) {
+    auto display_surface = std::static_pointer_cast<DisplaySurface>(surface);
+    display_surface->ManagerSetVisible(false);
+    display_surface->ClientSetVisible(false);
+    NotifyDisplayConfigurationUpdate();
+  }
+  // TODO(jwcai) Handle ChannelClose of VideoMeshSurface.
+}
+
+// First-level dispatch for display service messages. Directly handles messages
+// that are independent of the display surface (metrics, creation) and routes
+// surface-specific messages to the per-instance handlers.
+int DisplayService::HandleMessage(pdx::Message& message) {
+  auto channel = message.GetChannel<SurfaceChannel>();
+
+  switch (message.GetOp()) {
+    case DisplayRPC::GetMetrics::Opcode:
+      DispatchRemoteMethod<DisplayRPC::GetMetrics>(
+          *this, &DisplayService::OnGetMetrics, message);
+      return 0;
+
+    case DisplayRPC::GetEdsCapture::Opcode:
+      DispatchRemoteMethod<DisplayRPC::GetEdsCapture>(
+          *this, &DisplayService::OnGetEdsCapture, message);
+      return 0;
+
+    case DisplayRPC::CreateSurface::Opcode:
+      DispatchRemoteMethod<DisplayRPC::CreateSurface>(
+          *this, &DisplayService::OnCreateSurface, message);
+      return 0;
+
+    case DisplayRPC::EnterVrMode::Opcode:
+      DispatchRemoteMethod<DisplayRPC::EnterVrMode>(
+          *this, &DisplayService::OnEnterVrMode, message);
+      return 0;
+
+    case DisplayRPC::ExitVrMode::Opcode:
+      DispatchRemoteMethod<DisplayRPC::ExitVrMode>(
+          *this, &DisplayService::OnExitVrMode, message);
+      return 0;
+
+    case DisplayRPC::SetViewerParams::Opcode:
+      DispatchRemoteMethod<DisplayRPC::SetViewerParams>(
+          *this, &DisplayService::OnSetViewerParams, message);
+      return 0;
+
+    // Direct the surface specific messages to the surface instance.
+    case DisplayRPC::AllocateBuffer::Opcode:
+    case DisplayRPC::SetAttributes::Opcode:
+    case DisplayRPC::GetMetadataBuffer::Opcode:
+    case DisplayRPC::CreateVideoMeshSurface::Opcode:
+    case DisplayRPC::VideoMeshSurfaceCreateProducerQueue::Opcode:
+      return HandleSurfaceMessage(message);
+
+    default:
+      return Service::HandleMessage(message);
+  }
+}
+
+SystemDisplayMetrics DisplayService::OnGetMetrics(pdx::Message& message) {
+  const Compositor* compositor = hardware_composer_.GetCompositor();
+  if (compositor == nullptr)
+    REPLY_ERROR_RETURN(message, EINVAL, {});
+
+  HeadMountMetrics head_mount = compositor->head_mount_metrics();
+  CompositeHmd hmd(head_mount, hardware_composer_.GetHmdDisplayMetrics());
+  vec2i distorted_render_size = hmd.GetRecommendedRenderTargetSize();
+  FieldOfView left_fov = hmd.GetEyeFov(kLeftEye);
+  FieldOfView right_fov = hmd.GetEyeFov(kRightEye);
+
+  SystemDisplayMetrics metrics;
+
+  metrics.display_native_width = GetDisplayMetrics().width;
+  metrics.display_native_height = GetDisplayMetrics().height;
+  metrics.display_x_dpi = GetDisplayMetrics().dpi.x;
+  metrics.display_y_dpi = GetDisplayMetrics().dpi.y;
+  metrics.distorted_width = distorted_render_size[0];
+  metrics.distorted_height = distorted_render_size[1];
+  metrics.vsync_period_ns =
+      hardware_composer_.native_display_metrics().vsync_period_ns;
+  metrics.hmd_ipd_mm = 0;
+  metrics.inter_lens_distance_m = head_mount.GetInterLensDistance();
+  metrics.left_fov_lrbt[0] = left_fov.GetLeft();
+  metrics.left_fov_lrbt[1] = left_fov.GetRight();
+  metrics.left_fov_lrbt[2] = left_fov.GetBottom();
+  metrics.left_fov_lrbt[3] = left_fov.GetTop();
+  metrics.right_fov_lrbt[0] = right_fov.GetLeft();
+  metrics.right_fov_lrbt[1] = right_fov.GetRight();
+  metrics.right_fov_lrbt[2] = right_fov.GetBottom();
+  metrics.right_fov_lrbt[3] = right_fov.GetTop();
+
+  return metrics;
+}
+
+// Creates a new DisplaySurface and associates it with this channel. This may
+// only be done once per channel.
+int DisplayService::OnCreateSurface(pdx::Message& message, int width,
+                                    int height, int format, int usage,
+                                    DisplaySurfaceFlags flags) {
+  // A surface may only be created once per channel.
+  if (message.GetChannel())
+    return -EINVAL;
+
+  ALOGI_IF(TRACE, "DisplayService::OnCreateSurface: cid=%d",
+           message.GetChannelId());
+
+  // Use the channel id as the unique surface id.
+  const int surface_id = message.GetChannelId();
+  const int process_id = message.GetProcessId();
+
+  ALOGI_IF(TRACE,
+           "DisplayService::OnCreateSurface: surface_id=%d process_id=%d "
+           "width=%d height=%d format=%x usage=%x flags=%x",
+           surface_id, process_id, width, height, format, usage, flags);
+
+  // TODO(eieio,jbates): Validate request parameters.
+  auto channel = std::make_shared<DisplaySurface>(
+      this, surface_id, process_id, width, height, format, usage, flags);
+
+  message.SetChannel(channel);
+  NotifyDisplayConfigurationUpdate();
+  return 0;
+}
+
+DisplayRPC::ByteBuffer DisplayService::OnGetEdsCapture(pdx::Message& message) {
+  Compositor* compositor = hardware_composer_.GetCompositor();
+  if (compositor == nullptr)
+    REPLY_ERROR_RETURN(message, EINVAL, {});
+
+  std::vector<std::uint8_t> buffer(sizeof(LateLatchOutput));
+
+  if (!compositor->GetLastEdsPose(
+          reinterpret_cast<LateLatchOutput*>(buffer.data()))) {
+    REPLY_ERROR_RETURN(message, EPERM, {});
+  }
+
+  return WrapBuffer(std::move(buffer));
+}
+
+int DisplayService::OnEnterVrMode(pdx::Message& /*message*/) {
+  hardware_composer_.Resume();
+  return 0;
+}
+
+int DisplayService::OnExitVrMode(pdx::Message& /*message*/) {
+  hardware_composer_.Suspend();
+  return 0;
+}
+
+void DisplayService::OnSetViewerParams(pdx::Message& message,
+                                       const ViewerParams& view_params) {
+  Compositor* compositor = hardware_composer_.GetCompositor();
+  if (compositor == nullptr)
+    REPLY_ERROR_RETURN(message, EINVAL);
+
+  FieldOfView left(55.0f, 55.0f, 55.0f, 55.0f);
+  FieldOfView right(55.0f, 55.0f, 55.0f, 55.0f);
+  if (view_params.left_eye_field_of_view_angles.size() >= 4) {
+    left = FieldOfView(ToRad(view_params.left_eye_field_of_view_angles[0]),
+                       ToRad(view_params.left_eye_field_of_view_angles[1]),
+                       ToRad(view_params.left_eye_field_of_view_angles[2]),
+                       ToRad(view_params.left_eye_field_of_view_angles[3]));
+    right = FieldOfView(ToRad(view_params.left_eye_field_of_view_angles[1]),
+                        ToRad(view_params.left_eye_field_of_view_angles[0]),
+                        ToRad(view_params.left_eye_field_of_view_angles[2]),
+                        ToRad(view_params.left_eye_field_of_view_angles[3]));
+  }
+
+  std::shared_ptr<ColorChannelDistortion> red_distortion;
+  std::shared_ptr<ColorChannelDistortion> green_distortion;
+  std::shared_ptr<ColorChannelDistortion> blue_distortion;
+
+  // We should always have a red distortion.
+  LOG_FATAL_IF(view_params.distortion_coefficients_r.empty());
+  red_distortion = std::make_shared<PolynomialRadialDistortion>(
+      view_params.distortion_coefficients_r);
+
+  if (!view_params.distortion_coefficients_g.empty()) {
+    green_distortion = std::make_shared<PolynomialRadialDistortion>(
+        view_params.distortion_coefficients_g);
+  }
+
+  if (!view_params.distortion_coefficients_b.empty()) {
+    blue_distortion = std::make_shared<PolynomialRadialDistortion>(
+        view_params.distortion_coefficients_b);
+  }
+
+  HeadMountMetrics::EyeOrientation left_orientation =
+      HeadMountMetrics::EyeOrientation::kCCW0Degrees;
+  HeadMountMetrics::EyeOrientation right_orientation =
+      HeadMountMetrics::EyeOrientation::kCCW0Degrees;
+
+  if (view_params.eye_orientations.size() > 1) {
+    left_orientation = static_cast<HeadMountMetrics::EyeOrientation>(
+        view_params.eye_orientations[0]);
+    right_orientation = static_cast<HeadMountMetrics::EyeOrientation>(
+        view_params.eye_orientations[1]);
+  }
+
+  HeadMountMetrics head_mount_metrics(
+      view_params.inter_lens_distance, view_params.tray_to_lens_distance,
+      view_params.screen_to_lens_distance,
+      static_cast<HeadMountMetrics::VerticalAlignment>(
+          view_params.vertical_alignment),
+      left, right, red_distortion, green_distortion, blue_distortion,
+      left_orientation, right_orientation,
+      view_params.screen_center_to_lens_distance);
+
+  compositor->UpdateHeadMountMetrics(head_mount_metrics);
+}
+
+// Calls the message handler for the DisplaySurface associated with this
+// channel.
+int DisplayService::HandleSurfaceMessage(pdx::Message& message) {
+  auto surface = std::static_pointer_cast<SurfaceChannel>(message.GetChannel());
+  ALOGW_IF(!surface,
+           "DisplayService::HandleSurfaceMessage: surface is nullptr!");
+
+  if (surface)
+    return surface->HandleMessage(message);
+  else
+    REPLY_ERROR_RETURN(message, EINVAL, 0);
+}
+
+std::shared_ptr<DisplaySurface> DisplayService::GetDisplaySurface(
+    int surface_id) const {
+  return std::static_pointer_cast<DisplaySurface>(GetChannel(surface_id));
+}
+
+std::vector<std::shared_ptr<DisplaySurface>>
+DisplayService::GetDisplaySurfaces() const {
+  return GetChannels<DisplaySurface>();
+}
+
+std::vector<std::shared_ptr<DisplaySurface>>
+DisplayService::GetVisibleDisplaySurfaces() const {
+  std::vector<std::shared_ptr<DisplaySurface>> visible_surfaces;
+
+  ForEachDisplaySurface(
+      [&](const std::shared_ptr<DisplaySurface>& surface) mutable {
+        if (surface->IsVisible())
+          visible_surfaces.push_back(surface);
+      });
+
+  return visible_surfaces;
+}
+
+int DisplayService::UpdateActiveDisplaySurfaces() {
+  auto visible_surfaces = GetVisibleDisplaySurfaces();
+
+  // Sort the surfaces based on manager z order first, then client z order.
+  std::sort(visible_surfaces.begin(), visible_surfaces.end(),
+            [](const std::shared_ptr<DisplaySurface>& a,
+               const std::shared_ptr<DisplaySurface>& b) {
+              return a->manager_z_order() != b->manager_z_order()
+                         ? a->manager_z_order() < b->manager_z_order()
+                         : a->client_z_order() < b->client_z_order();
+            });
+
+  ALOGD_IF(TRACE,
+           "DisplayService::UpdateActiveDisplaySurfaces: %zd visible surfaces",
+           visible_surfaces.size());
+
+  // TODO(jbates) Have the shell manage blurred layers.
+  bool blur_requested = false;
+  auto end = visible_surfaces.crend();
+  for (auto it = visible_surfaces.crbegin(); it != end; ++it) {
+    auto surface = *it;
+    // Surfaces with exclude_from_blur==true are not blurred
+    // and are excluded from blur computation of other layers.
+    if (surface->client_exclude_from_blur()) {
+      surface->ManagerSetBlur(0.0f);
+      continue;
+    }
+    surface->ManagerSetBlur(blur_requested ? 1.0f : 0.0f);
+    if (surface->client_blur_behind())
+      blur_requested = true;
+  }
+  return hardware_composer_.SetDisplaySurfaces(std::move(visible_surfaces));
+}
+
+void DisplayService::SetDisplayConfigurationUpdateNotifier(
+    DisplayConfigurationUpdateNotifier update_notifier) {
+  update_notifier_ = update_notifier;
+}
+
+void DisplayService::NotifyDisplayConfigurationUpdate() {
+  if (update_notifier_)
+    update_notifier_();
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/display_service.h b/libs/vr/libvrflinger/display_service.h
new file mode 100644
index 0000000..ebd97de
--- /dev/null
+++ b/libs/vr/libvrflinger/display_service.h
@@ -0,0 +1,107 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_DISPLAY_SERVICE_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_DISPLAY_SERVICE_H_
+
+#include <pdx/service.h>
+#include <private/dvr/buffer_hub_client.h>
+#include <private/dvr/display_rpc.h>
+#include <private/dvr/late_latch.h>
+
+#include <functional>
+#include <iterator>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "acquired_buffer.h"
+#include "display_surface.h"
+#include "epoll_event_dispatcher.h"
+#include "hardware_composer.h"
+
+namespace android {
+namespace dvr {
+
+// DisplayService implements the displayd display service over ServiceFS.
+class DisplayService : public pdx::ServiceBase<DisplayService> {
+ public:
+  std::string DumpState(size_t max_length) override;
+
+  void OnChannelClose(pdx::Message& message,
+                      const std::shared_ptr<pdx::Channel>& channel) override;
+  int HandleMessage(pdx::Message& message) override;
+
+  std::shared_ptr<DisplaySurface> GetDisplaySurface(int surface_id) const;
+  std::vector<std::shared_ptr<DisplaySurface>> GetDisplaySurfaces() const;
+  std::vector<std::shared_ptr<DisplaySurface>> GetVisibleDisplaySurfaces()
+      const;
+
+  // Updates the list of actively displayed surfaces. This must be called after
+  // any change to client/manager attributes that affect visibility or z order.
+  int UpdateActiveDisplaySurfaces();
+
+  template <class A>
+  void ForEachDisplaySurface(A action) const {
+    ForEachChannel([action](const ChannelIterator::value_type& pair) mutable {
+      auto surface = std::static_pointer_cast<SurfaceChannel>(pair.second);
+      if (surface->type() == SurfaceTypeEnum::Normal)
+        action(std::static_pointer_cast<DisplaySurface>(surface));
+    });
+  }
+
+  using DisplayConfigurationUpdateNotifier = std::function<void(void)>;
+  void SetDisplayConfigurationUpdateNotifier(
+      DisplayConfigurationUpdateNotifier notifier);
+
+  using VSyncCallback = HardwareComposer::VSyncCallback;
+  void SetVSyncCallback(VSyncCallback callback) {
+    hardware_composer_.SetVSyncCallback(callback);
+  }
+
+  HWCDisplayMetrics GetDisplayMetrics() {
+    return hardware_composer_.display_metrics();
+  }
+
+  void SetActive(bool activated) {
+    if (activated) {
+      hardware_composer_.Resume();
+    } else {
+      hardware_composer_.Suspend();
+    }
+  }
+
+ private:
+  friend BASE;
+  friend DisplaySurface;
+
+  friend class VrDisplayStateService;
+
+  DisplayService();
+  DisplayService(android::Hwc2::Composer* hidl);
+
+  SystemDisplayMetrics OnGetMetrics(pdx::Message& message);
+  int OnCreateSurface(pdx::Message& message, int width, int height,
+                      int format, int usage, DisplaySurfaceFlags flags);
+
+  DisplayRPC::ByteBuffer OnGetEdsCapture(pdx::Message& message);
+
+  int OnEnterVrMode(pdx::Message& message);
+  int OnExitVrMode(pdx::Message& message);
+  void OnSetViewerParams(pdx::Message& message, const ViewerParams& view_params);
+
+  // Called by DisplaySurface to signal that a surface property has changed and
+  // the display manager should be notified.
+  void NotifyDisplayConfigurationUpdate();
+
+  int HandleSurfaceMessage(pdx::Message& message);
+
+  DisplayService(const DisplayService&) = delete;
+  void operator=(const DisplayService&) = delete;
+
+  EpollEventDispatcher dispatcher_;
+  HardwareComposer hardware_composer_;
+  DisplayConfigurationUpdateNotifier update_notifier_;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_DISPLAY_SERVICE_H_
diff --git a/libs/vr/libvrflinger/display_surface.cpp b/libs/vr/libvrflinger/display_surface.cpp
new file mode 100644
index 0000000..dff08b5
--- /dev/null
+++ b/libs/vr/libvrflinger/display_surface.cpp
@@ -0,0 +1,435 @@
+#include "display_surface.h"
+
+#include <utils/Trace.h>
+
+#include <private/dvr/platform_defines.h>
+
+#include "display_service.h"
+#include "hardware_composer.h"
+
+#define LOCAL_TRACE 1
+
+using android::pdx::BorrowedChannelHandle;
+using android::pdx::LocalChannelHandle;
+using android::pdx::Message;
+using android::pdx::RemoteChannelHandle;
+using android::pdx::Status;
+using android::pdx::rpc::DispatchRemoteMethod;
+using android::pdx::rpc::IfAnyOf;
+
+namespace android {
+namespace dvr {
+
+DisplaySurface::DisplaySurface(DisplayService* service, int surface_id,
+                               int process_id, int width, int height,
+                               int format, int usage, int flags)
+    : SurfaceChannel(service, surface_id, SurfaceTypeEnum::Normal,
+                     sizeof(DisplaySurfaceMetadata)),
+      process_id_(process_id),
+      posted_buffers_(kMaxPostedBuffers),
+      video_mesh_surfaces_updated_(false),
+      width_(width),
+      height_(height),
+      format_(format),
+      usage_(usage),
+      flags_(flags),
+      client_visible_(false),
+      client_z_order_(0),
+      client_exclude_from_blur_(false),
+      client_blur_behind_(false),
+      manager_visible_(false),
+      manager_z_order_(0),
+      manager_blur_(0.0f),
+      allocated_buffer_index_(0),
+      layer_order_(0) {}
+
+DisplaySurface::~DisplaySurface() {
+  ALOGD_IF(LOCAL_TRACE,
+           "DisplaySurface::~DisplaySurface: surface_id=%d process_id=%d",
+           surface_id(), process_id_);
+}
+
+void DisplaySurface::ManagerSetVisible(bool visible) {
+  std::lock_guard<std::mutex> autolock(lock_);
+  manager_visible_ = visible;
+}
+
+void DisplaySurface::ManagerSetZOrder(int z_order) {
+  std::lock_guard<std::mutex> autolock(lock_);
+  manager_z_order_ = z_order;
+}
+
+void DisplaySurface::ManagerSetBlur(float blur) {
+  std::lock_guard<std::mutex> autolock(lock_);
+  manager_blur_ = blur;
+}
+
+void DisplaySurface::ClientSetVisible(bool visible) {
+  std::lock_guard<std::mutex> autolock(lock_);
+  client_visible_ = visible;
+}
+
+void DisplaySurface::ClientSetZOrder(int z_order) {
+  std::lock_guard<std::mutex> autolock(lock_);
+  client_z_order_ = z_order;
+}
+
+void DisplaySurface::ClientSetExcludeFromBlur(bool exclude_from_blur) {
+  std::lock_guard<std::mutex> autolock(lock_);
+  client_exclude_from_blur_ = exclude_from_blur;
+}
+
+void DisplaySurface::ClientSetBlurBehind(bool blur_behind) {
+  std::lock_guard<std::mutex> autolock(lock_);
+  client_blur_behind_ = blur_behind;
+}
+
+size_t DisplaySurface::GetBufferCount() const {
+  std::lock_guard<std::mutex> autolock(lock_);
+  return buffers_.size();
+}
+
+std::vector<std::shared_ptr<BufferConsumer>> DisplaySurface::GetBuffers() {
+  std::lock_guard<std::mutex> autolock(lock_);
+  std::vector<std::shared_ptr<BufferConsumer>> return_vector(buffers_.size());
+
+  for (const auto pair : buffers_) {
+    return_vector.push_back(pair.second);
+  }
+
+  return return_vector;
+}
+
+AcquiredBuffer DisplaySurface::AcquireNewestAvailableBuffer(
+    AcquiredBuffer* skipped_buffer) {
+  std::lock_guard<std::mutex> autolock(lock_);
+  AcquiredBuffer buffer;
+  int frames = 0;
+  // Basic latency stopgap for when the application misses a frame:
+  // If the application recovers on the 2nd or 3rd (etc) frame after
+  // missing, this code will skip frames to catch up by checking if
+  // the next frame is also available.
+  while (!posted_buffers_.IsEmpty() && posted_buffers_.Front().IsAvailable()) {
+    // Capture the skipped buffer into the result parameter.
+    // Note that this API only supports skipping one buffer per vsync.
+    if (frames > 0 && skipped_buffer)
+      *skipped_buffer = std::move(buffer);
+    ++frames;
+    buffer = std::move(posted_buffers_.Front());
+    posted_buffers_.PopFront();
+    if (frames == 2)
+      break;
+  }
+  return buffer;
+}
+
+bool DisplaySurface::IsBufferAvailable() const {
+  std::lock_guard<std::mutex> autolock(lock_);
+  return !posted_buffers_.IsEmpty() && posted_buffers_.Front().IsAvailable();
+}
+
+bool DisplaySurface::IsBufferPosted() const {
+  std::lock_guard<std::mutex> autolock(lock_);
+  return !posted_buffers_.IsEmpty();
+}
+
+AcquiredBuffer DisplaySurface::AcquireCurrentBuffer() {
+  std::lock_guard<std::mutex> autolock(lock_);
+  if (posted_buffers_.IsEmpty()) {
+    ALOGE("Error: attempt to acquire buffer when none are posted.");
+    return AcquiredBuffer();
+  }
+  AcquiredBuffer buffer = std::move(posted_buffers_.Front());
+  posted_buffers_.PopFront();
+  return buffer;
+}
+
+int DisplaySurface::GetConsumers(std::vector<LocalChannelHandle>* consumers) {
+  std::lock_guard<std::mutex> autolock(lock_);
+  std::vector<LocalChannelHandle> items;
+
+  for (auto pair : buffers_) {
+    const auto& buffer = pair.second;
+
+    Status<LocalChannelHandle> consumer_channel = buffer->CreateConsumer();
+    if (!consumer_channel) {
+      ALOGE(
+          "DisplaySurface::GetConsumers: Failed to get a new consumer for "
+          "buffer %d: %s",
+          buffer->id(), consumer_channel.GetErrorMessage().c_str());
+      return -consumer_channel.error();
+    }
+
+    items.push_back(consumer_channel.take());
+  }
+
+  *consumers = std::move(items);
+  return 0;
+}
+
+int DisplaySurface::HandleMessage(pdx::Message& message) {
+  switch (message.GetOp()) {
+    case DisplayRPC::SetAttributes::Opcode:
+      DispatchRemoteMethod<DisplayRPC::SetAttributes>(
+          *this, &DisplaySurface::OnClientSetAttributes, message);
+      break;
+
+    case DisplayRPC::AllocateBuffer::Opcode:
+      DispatchRemoteMethod<DisplayRPC::AllocateBuffer>(
+          *this, &DisplaySurface::OnAllocateBuffer, message);
+      break;
+
+    case DisplayRPC::CreateVideoMeshSurface::Opcode:
+      DispatchRemoteMethod<DisplayRPC::CreateVideoMeshSurface>(
+          *this, &DisplaySurface::OnCreateVideoMeshSurface, message);
+      break;
+
+    default:
+      return SurfaceChannel::HandleMessage(message);
+  }
+
+  return 0;
+}
+
+int DisplaySurface::OnClientSetAttributes(
+    pdx::Message& /*message*/, const DisplaySurfaceAttributes& attributes) {
+  for (const auto& attribute : attributes) {
+    const auto& key = attribute.first;
+    const auto* variant = &attribute.second;
+    bool invalid_value = false;
+    switch (key) {
+      case DisplaySurfaceAttributeEnum::ZOrder:
+        invalid_value = !IfAnyOf<int32_t, int64_t, float>::Call(
+            variant, [this](const auto& value) {
+              DisplaySurface::ClientSetZOrder(value);
+            });
+        break;
+      case DisplaySurfaceAttributeEnum::Visible:
+        invalid_value = !IfAnyOf<int32_t, int64_t, bool>::Call(
+            variant, [this](const auto& value) {
+              DisplaySurface::ClientSetVisible(value);
+            });
+        break;
+      case DisplaySurfaceAttributeEnum::ExcludeFromBlur:
+        invalid_value = !IfAnyOf<int32_t, int64_t, bool>::Call(
+            variant, [this](const auto& value) {
+              DisplaySurface::ClientSetExcludeFromBlur(value);
+            });
+        break;
+      case DisplaySurfaceAttributeEnum::BlurBehind:
+        invalid_value = !IfAnyOf<int32_t, int64_t, bool>::Call(
+            variant, [this](const auto& value) {
+              DisplaySurface::ClientSetBlurBehind(value);
+            });
+        break;
+      default:
+        ALOGW(
+            "DisplaySurface::OnClientSetAttributes: Unrecognized attribute %d "
+            "surface_id=%d",
+            key, surface_id());
+        break;
+    }
+
+    if (invalid_value) {
+      ALOGW(
+          "DisplaySurface::OnClientSetAttributes: Failed to set display "
+          "surface attribute '%s' because of incompatible type: %d",
+          DisplaySurfaceAttributeEnum::ToString(key).c_str(), variant->index());
+    }
+  }
+
+  service()->NotifyDisplayConfigurationUpdate();
+  return 0;
+}
+
+// Allocates a new buffer for the DisplaySurface associated with this channel.
+std::pair<uint32_t, LocalChannelHandle> DisplaySurface::OnAllocateBuffer(
+    pdx::Message& message) {
+  // Inject flag to enable framebuffer compression for the application buffers.
+  // TODO(eieio,jbates): Make this configurable per hardware platform.
+  const int usage = usage_ | GRALLOC_USAGE_QCOM_FRAMEBUFFER_COMPRESSION;
+  const int slice_count =
+      (flags_ & static_cast<int>(DisplaySurfaceFlagsEnum::SeparateGeometry))
+          ? 2
+          : 1;
+
+  ALOGI_IF(
+      TRACE,
+      "DisplaySurface::OnAllocateBuffer: width=%d height=%d format=%x usage=%x "
+      "slice_count=%d",
+      width_, height_, format_, usage, slice_count);
+
+  // Create a producer buffer to hand back to the sender.
+  auto producer = BufferProducer::Create(width_, height_, format_, usage,
+                                         sizeof(uint64_t), slice_count);
+  if (!producer)
+    REPLY_ERROR_RETURN(message, EINVAL, {});
+
+  // Create and import a consumer attached to the producer.
+  Status<LocalChannelHandle> consumer_channel = producer->CreateConsumer();
+  if (!consumer_channel)
+    REPLY_ERROR_RETURN(message, consumer_channel.error(), {});
+
+  std::shared_ptr<BufferConsumer> consumer =
+      BufferConsumer::Import(consumer_channel.take());
+  if (!consumer)
+    REPLY_ERROR_RETURN(message, ENOMEM, {});
+
+  // Add the consumer to this surface.
+  int err = AddConsumer(consumer);
+  if (err < 0) {
+    ALOGE("DisplaySurface::OnAllocateBuffer: failed to add consumer: buffer=%d",
+          consumer->id());
+    REPLY_ERROR_RETURN(message, -err, {});
+  }
+
+  // Move the channel handle so that it doesn't get closed when the producer
+  // goes out of scope.
+  std::pair<uint32_t, LocalChannelHandle> return_value(
+      allocated_buffer_index_, std::move(producer->GetChannelHandle()));
+
+  // Save buffer index, associated with the buffer id so that it can be looked
+  // up later.
+  buffer_id_to_index_[consumer->id()] = allocated_buffer_index_;
+  ++allocated_buffer_index_;
+
+  return return_value;
+}
+
+RemoteChannelHandle DisplaySurface::OnCreateVideoMeshSurface(
+    pdx::Message& message) {
+  if (flags_ & DVR_DISPLAY_SURFACE_FLAGS_DISABLE_SYSTEM_DISTORTION) {
+    ALOGE(
+        "DisplaySurface::OnCreateVideoMeshSurface: system distorion is "
+        "disabled on this display surface, cannot create VideoMeshSurface on "
+        "top of it.");
+    REPLY_ERROR_RETURN(message, EINVAL, {});
+  }
+
+  int channel_id;
+  auto status = message.PushChannel(0, nullptr, &channel_id);
+
+  if (!status) {
+    ALOGE(
+        "DisplaySurface::OnCreateVideoMeshSurface: failed to push channel: %s",
+        status.GetErrorMessage().c_str());
+    REPLY_ERROR_RETURN(message, ENOMEM, {});
+  }
+
+  auto surface = std::make_shared<VideoMeshSurface>(service(), channel_id);
+  const int ret = service()->SetChannel(channel_id, surface);
+  if (ret < 0) {
+    ALOGE(
+        "DisplaySurface::OnCreateVideoMeshSurface: failed to set new video "
+        "mesh surface channel: %s",
+        strerror(-ret));
+    REPLY_ERROR_RETURN(message, ENOMEM, {});
+  }
+
+  {
+    std::lock_guard<std::mutex> autolock(lock_);
+    pending_video_mesh_surfaces_.push_back(surface);
+    video_mesh_surfaces_updated_ = true;
+  }
+
+  return status.take();
+}
+
+int DisplaySurface::AddConsumer(
+    const std::shared_ptr<BufferConsumer>& consumer) {
+  ALOGD_IF(TRACE, "DisplaySurface::AddConsumer: buffer_id=%d", consumer->id());
+  // Add the consumer to the epoll dispatcher, edge-triggered.
+  int err = service()->dispatcher_.AddEventHandler(
+      consumer->event_fd(), EPOLLET | EPOLLIN | EPOLLHUP,
+      std::bind(&DisplaySurface::HandleConsumerEvents,
+                std::static_pointer_cast<DisplaySurface>(shared_from_this()),
+                consumer, std::placeholders::_1));
+  if (err) {
+    ALOGE(
+        "DisplaySurface::AddConsumer: failed to add epoll event handler for "
+        "consumer: %s",
+        strerror(-err));
+    return err;
+  }
+
+  // Add the consumer to the list of buffers for this surface.
+  std::lock_guard<std::mutex> autolock(lock_);
+  buffers_.insert(std::make_pair(consumer->id(), consumer));
+  return 0;
+}
+
+void DisplaySurface::RemoveConsumer(
+    const std::shared_ptr<BufferConsumer>& consumer) {
+  ALOGD_IF(TRACE, "DisplaySurface::RemoveConsumer: buffer_id=%d",
+           consumer->id());
+  service()->dispatcher_.RemoveEventHandler(consumer->event_fd());
+
+  std::lock_guard<std::mutex> autolock(lock_);
+  buffers_.erase(consumer->id());
+}
+
+void DisplaySurface::RemoveConsumerUnlocked(
+    const std::shared_ptr<BufferConsumer>& consumer) {
+  ALOGD_IF(TRACE, "DisplaySurface::RemoveConsumerUnlocked: buffer_id=%d",
+           consumer->id());
+  service()->dispatcher_.RemoveEventHandler(consumer->event_fd());
+  buffers_.erase(consumer->id());
+}
+
+void DisplaySurface::OnPostConsumer(
+    const std::shared_ptr<BufferConsumer>& consumer) {
+  ATRACE_NAME("DisplaySurface::OnPostConsumer");
+  std::lock_guard<std::mutex> autolock(lock_);
+
+  if (posted_buffers_.IsFull()) {
+    ALOGE("Error: posted buffers full, overwriting");
+    posted_buffers_.PopBack();
+  }
+
+  int error;
+  posted_buffers_.Append(AcquiredBuffer(consumer, &error));
+
+  // Remove the consumer if the other end was closed.
+  if (posted_buffers_.Back().IsEmpty() && error == -EPIPE)
+    RemoveConsumerUnlocked(consumer);
+}
+
+void DisplaySurface::HandleConsumerEvents(
+    const std::shared_ptr<BufferConsumer>& consumer, int events) {
+  if (events & EPOLLHUP) {
+    ALOGD_IF(TRACE,
+             "DisplaySurface::HandleConsumerEvents: removing event handler for "
+             "buffer=%d",
+             consumer->id());
+    RemoveConsumer(consumer);
+  } else if (events & EPOLLIN) {
+    // BufferHub uses EPOLLIN to signal consumer ownership.
+    ALOGD_IF(TRACE,
+             "DisplaySurface::HandleConsumerEvents: posting buffer=%d for "
+             "process=%d",
+             consumer->id(), process_id_);
+
+    OnPostConsumer(consumer);
+  }
+}
+
+std::vector<std::shared_ptr<VideoMeshSurface>>
+DisplaySurface::GetVideoMeshSurfaces() {
+  std::lock_guard<std::mutex> autolock(lock_);
+  std::vector<std::shared_ptr<VideoMeshSurface>> surfaces;
+
+  for (auto& surface : pending_video_mesh_surfaces_) {
+    if (auto video_surface = surface.lock()) {
+      surfaces.push_back(video_surface);
+    } else {
+      ALOGE("Unable to lock video mesh surface.");
+    }
+  }
+
+  pending_video_mesh_surfaces_.clear();
+  video_mesh_surfaces_updated_ = false;
+  return surfaces;
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/display_surface.h b/libs/vr/libvrflinger/display_surface.h
new file mode 100644
index 0000000..b7bcd97
--- /dev/null
+++ b/libs/vr/libvrflinger/display_surface.h
@@ -0,0 +1,211 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_DISPLAY_SURFACE_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_DISPLAY_SURFACE_H_
+
+#include <pdx/file_handle.h>
+#include <pdx/service.h>
+#include <private/dvr/display_rpc.h>
+#include <private/dvr/ring_buffer.h>
+
+#include <functional>
+#include <iterator>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "acquired_buffer.h"
+#include "epoll_event_dispatcher.h"
+#include "surface_channel.h"
+#include "video_mesh_surface.h"
+
+namespace android {
+namespace dvr {
+
+class DisplayService;
+
+// DisplaySurface is the service-side notion of a client display context. It is
+// responsible for managing display buffer format, geometry, and state, and
+// maintains the buffer consumers connected to the client.
+class DisplaySurface : public SurfaceChannel {
+ public:
+  DisplaySurface(DisplayService* service, int surface_id, int process_id,
+                 int width, int height, int format, int usage, int flags);
+  ~DisplaySurface() override;
+
+  int process_id() const { return process_id_; }
+  int width() const { return width_; }
+  int height() const { return height_; }
+  int format() const { return format_; }
+  int usage() const { return usage_; }
+  int flags() const { return flags_; }
+
+  bool client_visible() const { return client_visible_; }
+  int client_z_order() const { return client_z_order_; }
+  bool client_exclude_from_blur() const { return client_exclude_from_blur_; }
+  bool client_blur_behind() const { return client_blur_behind_; }
+
+  bool manager_visible() const { return manager_visible_; }
+  int manager_z_order() const { return manager_z_order_; }
+  float manager_blur() const { return manager_blur_; }
+
+  bool video_mesh_surfaces_updated() const {
+    return video_mesh_surfaces_updated_;
+  }
+
+  volatile const DisplaySurfaceMetadata* GetMetadataBufferPtr() {
+    if (EnsureMetadataBuffer()) {
+      void* addr = nullptr;
+      metadata_buffer_->GetBlobReadWritePointer(metadata_size(), &addr);
+      return static_cast<const volatile DisplaySurfaceMetadata*>(addr);
+    } else {
+      return nullptr;
+    }
+  }
+
+  uint32_t GetRenderBufferIndex(int buffer_id) {
+    return buffer_id_to_index_[buffer_id];
+  }
+
+  size_t GetBufferCount() const;
+  std::vector<std::shared_ptr<BufferConsumer>> GetBuffers();
+
+  // Gets a new set of consumers for all of the surface's buffers. These
+  // consumers are independent from the consumers maintained internally to the
+  // surface and may be passed to other processes over IPC.
+  int GetConsumers(std::vector<pdx::LocalChannelHandle>* consumers);
+
+  template <class A>
+  void ForEachBuffer(A action) {
+    std::lock_guard<std::mutex> autolock(lock_);
+    std::for_each(buffers_.begin(), buffers_.end(), action);
+  }
+
+  bool IsBufferAvailable() const;
+  bool IsBufferPosted() const;
+  AcquiredBuffer AcquireCurrentBuffer();
+
+  // Get the newest buffer. Up to one buffer will be skipped. If a buffer is
+  // skipped, it will be stored in skipped_buffer if non null.
+  AcquiredBuffer AcquireNewestAvailableBuffer(AcquiredBuffer* skipped_buffer);
+
+  // Display manager interface to control visibility and z order.
+  void ManagerSetVisible(bool visible);
+  void ManagerSetZOrder(int z_order);
+  void ManagerSetBlur(float blur);
+
+  // A surface must be set visible by both the client and the display manager to
+  // be visible on screen.
+  bool IsVisible() const { return client_visible_ && manager_visible_; }
+
+  // A surface is blurred if the display manager requests it.
+  bool IsBlurred() const { return manager_blur_ > 0.0f; }
+
+  // Set by HardwareComposer to the current logical layer order of this surface.
+  void SetLayerOrder(int layer_order) { layer_order_ = layer_order; }
+  // Gets the unique z-order index of this surface among other visible surfaces.
+  // This is not the same as the hardware layer index, as not all display
+  // surfaces map directly to hardware layers. Lower layer orders should be
+  // composited underneath higher layer orders.
+  int layer_order() const { return layer_order_; }
+
+  // Lock all video mesh surfaces so that VideoMeshCompositor can access them.
+  std::vector<std::shared_ptr<VideoMeshSurface>> GetVideoMeshSurfaces();
+
+ private:
+  friend class DisplayService;
+
+  // The capacity of the pending buffer queue. Should be enough to hold all the
+  // buffers of this DisplaySurface, although in practice only 1 or 2 frames
+  // will be pending at a time.
+  static constexpr int kMaxPostedBuffers =
+      kSurfaceBufferMaxCount * kSurfaceViewMaxCount;
+
+  // Returns whether a frame is available without locking the mutex.
+  bool IsFrameAvailableNoLock() const;
+
+  // Handles epoll events for BufferHub consumers. Events are mainly generated
+  // by producers posting buffers ready for display. This handler runs on the
+  // epoll event thread.
+  void HandleConsumerEvents(const std::shared_ptr<BufferConsumer>& consumer,
+                            int events);
+
+  // Dispatches display surface messages to the appropriate handlers. This
+  // handler runs on the displayd message dispatch thread.
+  int HandleMessage(pdx::Message& message) override;
+
+  // Sets display surface's client-controlled attributes.
+  int OnClientSetAttributes(pdx::Message& message,
+                            const DisplaySurfaceAttributes& attributes);
+
+  // Allocates a buffer with the display surface geometry and settings and
+  // returns it to the client.
+  std::pair<uint32_t, pdx::LocalChannelHandle> OnAllocateBuffer(
+      pdx::Message& message);
+
+  // Creates a video mesh surface associated with this surface and returns it
+  // to the client.
+  pdx::RemoteChannelHandle OnCreateVideoMeshSurface(pdx::Message& message);
+
+  // Sets the current buffer for the display surface, discarding the previous
+  // buffer if it is not already claimed. Runs on the epoll event thread.
+  void OnPostConsumer(const std::shared_ptr<BufferConsumer>& consumer);
+
+  // Client interface (called through IPC) to set visibility and z order.
+  void ClientSetVisible(bool visible);
+  void ClientSetZOrder(int z_order);
+  void ClientSetExcludeFromBlur(bool exclude_from_blur);
+  void ClientSetBlurBehind(bool blur_behind);
+
+  // Runs on the displayd message dispatch thread.
+  int AddConsumer(const std::shared_ptr<BufferConsumer>& consumer);
+
+  // Runs on the epoll event thread.
+  void RemoveConsumer(const std::shared_ptr<BufferConsumer>& consumer);
+
+  // Runs on the epoll and display post thread.
+  void RemoveConsumerUnlocked(const std::shared_ptr<BufferConsumer>& consumer);
+
+  DisplaySurface(const DisplaySurface&) = delete;
+  void operator=(const DisplaySurface&) = delete;
+
+  int process_id_;
+
+  // Synchronizes access to mutable state below between message dispatch thread,
+  // epoll event thread, and frame post thread.
+  mutable std::mutex lock_;
+  std::unordered_map<int, std::shared_ptr<BufferConsumer>> buffers_;
+
+  // In a triple-buffered surface, up to kMaxPostedBuffers buffers may be
+  // posted and pending.
+  RingBuffer<AcquiredBuffer> posted_buffers_;
+
+  // Provides access to VideoMeshSurface. Here we don't want to increase
+  // the reference count immediately on allocation, will leave it into
+  // compositor's hand.
+  std::vector<std::weak_ptr<VideoMeshSurface>> pending_video_mesh_surfaces_;
+  volatile bool video_mesh_surfaces_updated_;
+
+  // Surface parameters.
+  int width_;
+  int height_;
+  int format_;
+  int usage_;
+  int flags_;
+  bool client_visible_;
+  int client_z_order_;
+  bool client_exclude_from_blur_;
+  bool client_blur_behind_;
+  bool manager_visible_;
+  int manager_z_order_;
+  float manager_blur_;
+  // The monotonically increasing index for allocated buffers in this surface.
+  uint32_t allocated_buffer_index_;
+  int layer_order_;
+
+  // Maps from the buffer id to the corresponding allocated buffer index.
+  std::unordered_map<int, uint32_t> buffer_id_to_index_;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_DISPLAY_SURFACE_H_
diff --git a/libs/vr/libvrflinger/epoll_event_dispatcher.cpp b/libs/vr/libvrflinger/epoll_event_dispatcher.cpp
new file mode 100644
index 0000000..b37e76e
--- /dev/null
+++ b/libs/vr/libvrflinger/epoll_event_dispatcher.cpp
@@ -0,0 +1,142 @@
+#include "epoll_event_dispatcher.h"
+
+#include <log/log.h>
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+#include <sys/prctl.h>
+
+#include <dvr/performance_client_api.h>
+
+namespace android {
+namespace dvr {
+
+EpollEventDispatcher::EpollEventDispatcher()
+    : exit_thread_(false), epoll_fd_(-1), event_fd_(-1) {
+  epoll_fd_ = epoll_create(64);
+  if (epoll_fd_ < 0) {
+    ALOGE("Failed to create epoll fd: %s", strerror(errno));
+    return;
+  }
+
+  event_fd_ = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
+  if (event_fd_ < 0) {
+    ALOGE("Failed to create event for epolling: %s", strerror(errno));
+    return;
+  }
+
+  // Add watch for eventfd. This should only watch for EPOLLIN, which gets set
+  // when eventfd_write occurs. Use "this" as a unique sentinal value to
+  // identify events from the event fd.
+  epoll_event event = {.events = EPOLLIN, .data = {.ptr = this}};
+  if (epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, event_fd_, &event) < 0) {
+    ALOGE("Failed to add eventfd to epoll set because: %s", strerror(errno));
+    return;
+  }
+
+  thread_ = std::thread(&EpollEventDispatcher::EventThread, this);
+}
+
+EpollEventDispatcher::~EpollEventDispatcher() {
+  Stop();
+
+  close(epoll_fd_);
+  close(event_fd_);
+}
+
+void EpollEventDispatcher::Stop() {
+  exit_thread_.store(true);
+  eventfd_write(event_fd_, 1);
+}
+
+int EpollEventDispatcher::AddEventHandler(int fd, int event_mask,
+                                          Handler handler) {
+  std::lock_guard<std::mutex> lock(lock_);
+
+  epoll_event event;
+  event.events = event_mask;
+  event.data.ptr = &(handlers_[fd] = handler);
+
+  ALOGD_IF(
+      TRACE,
+      "EpollEventDispatcher::AddEventHandler: fd=%d event_mask=0x%x handler=%p",
+      fd, event_mask, event.data.ptr);
+
+  int err = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, fd, &event);
+  return err < 0 ? -errno : 0;
+}
+
+int EpollEventDispatcher::RemoveEventHandler(int fd) {
+  ALOGD_IF(TRACE, "EpollEventDispatcher::RemoveEventHandler: fd=%d", fd);
+  std::lock_guard<std::mutex> lock(lock_);
+
+  epoll_event dummy;  // See BUGS in man 2 epoll_ctl.
+  if (epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, fd, &dummy) < 0) {
+    ALOGE("Failed to remove fd from epoll set because: %s", strerror(errno));
+    return -errno;
+  }
+
+  // If the fd was valid above, add it to the list of ids to remove.
+  removed_handlers_.push_back(fd);
+
+  // Wake up the event thread to clean up.
+  eventfd_write(event_fd_, 1);
+
+  return 0;
+}
+
+void EpollEventDispatcher::EventThread() {
+  prctl(PR_SET_NAME, reinterpret_cast<unsigned long>("EpollEvent"), 0, 0, 0);
+
+  const int error = dvrSetSchedulerClass(0, "graphics");
+  LOG_ALWAYS_FATAL_IF(
+      error < 0,
+      "EpollEventDispatcher::EventThread: Failed to set scheduler class: %s",
+      strerror(-error));
+
+  const size_t kMaxNumEvents = 128;
+  epoll_event events[kMaxNumEvents];
+
+  while (!exit_thread_.load()) {
+    int num_events = epoll_wait(epoll_fd_, events, kMaxNumEvents, -1);
+    if (num_events < 0 && errno != EINTR)
+      break;
+
+    ALOGD_IF(TRACE, "EpollEventDispatcher::EventThread: num_events=%d",
+             num_events);
+
+    for (int i = 0; i < num_events; i++) {
+      ALOGD_IF(
+          TRACE,
+          "EpollEventDispatcher::EventThread: event %d: handler=%p events=0x%x",
+          i, events[i].data.ptr, events[i].events);
+
+      if (events[i].data.ptr == this) {
+        // Clear pending event on event_fd_. Serialize the read with respect to
+        // writes from other threads.
+        std::lock_guard<std::mutex> lock(lock_);
+        eventfd_t value;
+        eventfd_read(event_fd_, &value);
+      } else {
+        auto handler = reinterpret_cast<Handler*>(events[i].data.ptr);
+        if (handler)
+          (*handler)(events[i].events);
+      }
+    }
+
+    // Remove any handlers that have been posted for removal. This is done here
+    // instead of in RemoveEventHandler() to prevent races between the dispatch
+    // thread and the code requesting the removal. Handlers are guaranteed to
+    // stay alive between exiting epoll_wait() and the dispatch loop above.
+    std::lock_guard<std::mutex> lock(lock_);
+    for (auto handler_fd : removed_handlers_) {
+      ALOGD_IF(TRACE,
+               "EpollEventDispatcher::EventThread: removing handler: fd=%d",
+               handler_fd);
+      handlers_.erase(handler_fd);
+    }
+    removed_handlers_.clear();
+  }
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/epoll_event_dispatcher.h b/libs/vr/libvrflinger/epoll_event_dispatcher.h
new file mode 100644
index 0000000..43bca2e
--- /dev/null
+++ b/libs/vr/libvrflinger/epoll_event_dispatcher.h
@@ -0,0 +1,61 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_EPOLL_EVENT_DISPATCHER_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_EPOLL_EVENT_DISPATCHER_H_
+
+#include <sys/epoll.h>
+
+#include <atomic>
+#include <functional>
+#include <mutex>
+#include <thread>
+#include <unordered_map>
+#include <vector>
+
+namespace android {
+namespace dvr {
+
+class EpollEventDispatcher {
+ public:
+  // Function type for event handlers. The handler receives a bitmask of the
+  // epoll events that occurred on the file descriptor associated with the
+  // handler.
+  using Handler = std::function<void(int)>;
+
+  EpollEventDispatcher();
+  ~EpollEventDispatcher();
+
+  // |handler| is called on the internal dispatch thread when |fd| is signaled
+  // by events in |event_mask|.
+  // Return 0 on success or a negative error code on failure.
+  int AddEventHandler(int fd, int event_mask, Handler handler);
+  int RemoveEventHandler(int fd);
+
+  void Stop();
+
+ private:
+  void EventThread();
+
+  std::thread thread_;
+  std::atomic<bool> exit_thread_;
+
+  // Protects handlers_ and removed_handlers_ and serializes operations on
+  // epoll_fd_ and event_fd_.
+  std::mutex lock_;
+
+  // Maintains a map of fds to event handlers. This is primarily to keep any
+  // references alive that may be bound in the std::function instances. It is
+  // not used at dispatch time to avoid performance problems with different
+  // versions of std::unordered_map.
+  std::unordered_map<int, Handler> handlers_;
+
+  // List of fds to be removed from the map. The actual removal is performed
+  // by the event dispatch thread to avoid races.
+  std::vector<int> removed_handlers_;
+
+  int epoll_fd_;
+  int event_fd_;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_EPOLL_EVENT_DISPATCHER_H_
diff --git a/libs/vr/libvrflinger/hardware_composer.cpp b/libs/vr/libvrflinger/hardware_composer.cpp
new file mode 100644
index 0000000..e0b592e
--- /dev/null
+++ b/libs/vr/libvrflinger/hardware_composer.cpp
@@ -0,0 +1,1572 @@
+#include "hardware_composer.h"
+
+#include <log/log.h>
+#include <cutils/properties.h>
+#include <cutils/sched_policy.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <sync/sync.h>
+#include <sys/eventfd.h>
+#include <sys/prctl.h>
+#include <sys/resource.h>
+#include <sys/system_properties.h>
+#include <sys/timerfd.h>
+#include <unistd.h>
+#include <utils/Trace.h>
+
+#include <algorithm>
+#include <functional>
+#include <map>
+
+#include <dvr/performance_client_api.h>
+#include <private/dvr/clock_ns.h>
+#include <private/dvr/display_types.h>
+#include <private/dvr/pose_client_internal.h>
+#include <private/dvr/sync_util.h>
+
+#include "debug_hud_data.h"
+#include "screenshot_service.h"
+
+using android::pdx::LocalHandle;
+
+namespace android {
+namespace dvr {
+
+namespace {
+
+// If the number of pending fences goes over this count at the point when we
+// are about to submit a new frame to HWC, we will drop the frame. This should
+// be a signal that the display driver has begun queuing frames. Note that with
+// smart displays (with RAM), the fence is signaled earlier than the next vsync,
+// at the point when the DMA to the display completes. Currently we use a smart
+// display and the EDS timing coincides with zero pending fences, so this is 0.
+constexpr int kAllowedPendingFenceCount = 0;
+
+// If we think we're going to miss vsync by more than this amount, skip the
+// frame.
+constexpr int64_t kFrameSkipThresholdNs = 4000000;  // 4ms
+
+// Counter PostLayers() deficiency by requiring apps to produce a frame at least
+// 2.5ms before vsync. See b/28881672.
+constexpr int64_t kFrameTimeEstimateMin = 2500000;  // 2.5ms
+
+constexpr size_t kDefaultDisplayConfigCount = 32;
+
+constexpr float kMetersPerInch = 0.0254f;
+
+const char kBacklightBrightnessSysFile[] =
+    "/sys/class/leds/lcd-backlight/brightness";
+
+const char kPrimaryDisplayVSyncEventFile[] =
+    "/sys/class/graphics/fb0/vsync_event";
+
+const char kPrimaryDisplayWaitPPEventFile[] = "/sys/class/graphics/fb0/wait_pp";
+
+const char kDvrPerformanceProperty[] = "sys.dvr.performance";
+
+const char kRightEyeOffsetProperty[] = "dreamos.right_eye_offset_ns";
+
+// Returns our best guess for the time the compositor will spend rendering the
+// next frame.
+int64_t GuessFrameTime(int compositor_visible_layer_count) {
+  // The cost of asynchronous EDS and lens warp is currently measured at 2.5ms
+  // for one layer and 7ms for two layers, but guess a higher frame time to
+  // account for CPU overhead. This guess is only used before we've measured the
+  // actual time to render a frame for the current compositor configuration.
+  switch (compositor_visible_layer_count) {
+    case 0:
+      return 500000;  // .5ms
+    case 1:
+      return 5000000;  // 5ms
+    default:
+      return 10500000;  // 10.5ms
+  }
+}
+
+// Get time offset from a vsync to when the pose for that vsync should be
+// predicted out to. For example, if scanout gets halfway through the frame
+// at the halfway point between vsyncs, then this could be half the period.
+// With global shutter displays, this should be changed to the offset to when
+// illumination begins. Low persistence adds a frame of latency, so we predict
+// to the center of the next frame.
+inline int64_t GetPosePredictionTimeOffset(int64_t vsync_period_ns) {
+  return (vsync_period_ns * 150) / 100;
+}
+
+}  // anonymous namespace
+
+HardwareComposer::HardwareComposer()
+  : HardwareComposer(nullptr) {
+}
+
+HardwareComposer::HardwareComposer(Hwc2::Composer* hwc2_hidl)
+    : hwc2_hidl_(hwc2_hidl),
+      display_transform_(HWC_TRANSFORM_NONE),
+      display_surfaces_updated_(false),
+      hardware_layers_need_update_(false),
+      display_on_(false),
+      active_layer_count_(0),
+      gpu_layer_(nullptr),
+      terminate_post_thread_event_fd_(-1),
+      pause_post_thread_(true),
+      backlight_brightness_fd_(-1),
+      primary_display_vsync_event_fd_(-1),
+      primary_display_wait_pp_fd_(-1),
+      vsync_sleep_timer_fd_(-1),
+      last_vsync_timestamp_(0),
+      vsync_count_(0),
+      frame_skip_count_(0),
+      pose_client_(nullptr) {
+  std::transform(layer_storage_.begin(), layer_storage_.end(), layers_.begin(),
+                 [](auto& layer) { return &layer; });
+
+  callbacks_ = new ComposerCallback;
+}
+
+HardwareComposer::~HardwareComposer(void) {
+  if (!IsSuspended()) {
+    Suspend();
+  }
+}
+
+bool HardwareComposer::Resume() {
+  std::lock_guard<std::mutex> autolock(layer_mutex_);
+
+  if (!IsSuspended()) {
+    ALOGE("HardwareComposer::Resume: HardwareComposer is already running.");
+    return false;
+  }
+
+  int32_t ret = HWC2_ERROR_NONE;
+
+  static const uint32_t attributes[] = {
+      HWC_DISPLAY_WIDTH, HWC_DISPLAY_HEIGHT, HWC_DISPLAY_VSYNC_PERIOD,
+      HWC_DISPLAY_DPI_X, HWC_DISPLAY_DPI_Y,  HWC_DISPLAY_NO_ATTRIBUTE,
+  };
+
+  std::vector<Hwc2::Config> configs;
+  ret = (int32_t)hwc2_hidl_->getDisplayConfigs(HWC_DISPLAY_PRIMARY, &configs);
+
+  if (ret != HWC2_ERROR_NONE) {
+    ALOGE("HardwareComposer: Failed to get display configs");
+    return false;
+  }
+
+  uint32_t num_configs = configs.size();
+
+  for (size_t i = 0; i < num_configs; i++) {
+    ALOGI("HardwareComposer: cfg[%zd/%zd] = 0x%08x", i, num_configs,
+          configs[i]);
+
+    ret = GetDisplayMetrics(HWC_DISPLAY_PRIMARY, configs[i],
+                            &native_display_metrics_);
+
+    if (ret != HWC2_ERROR_NONE) {
+      ALOGE("HardwareComposer: Failed to get display attributes %d", ret);
+      continue;
+    } else {
+      ret =
+          (int32_t)hwc2_hidl_->setActiveConfig(HWC_DISPLAY_PRIMARY, configs[i]);
+
+      if (ret != HWC2_ERROR_NONE) {
+        ALOGE("HardwareComposer: Failed to set display configuration; ret=%d",
+              ret);
+        continue;
+      }
+
+      break;
+    }
+  }
+
+  if (ret != HWC2_ERROR_NONE) {
+    ALOGE("HardwareComposer: Could not set a valid display configuration.");
+    return false;
+  }
+
+  // Set the display metrics but never use rotation to avoid the long latency of
+  // rotation processing in hwc.
+  display_transform_ = HWC_TRANSFORM_NONE;
+  display_metrics_ = native_display_metrics_;
+
+  ALOGI(
+      "HardwareComposer: primary display attributes: width=%d height=%d "
+      "vsync_period_ns=%d DPI=%dx%d",
+      native_display_metrics_.width, native_display_metrics_.height,
+      native_display_metrics_.vsync_period_ns, native_display_metrics_.dpi.x,
+      native_display_metrics_.dpi.y);
+
+  // Always turn off vsync when we start.
+  EnableVsync(false);
+
+  constexpr int format = HAL_PIXEL_FORMAT_RGBA_8888;
+  constexpr int usage =
+      GRALLOC_USAGE_HW_FB | GRALLOC_USAGE_HW_COMPOSER | GRALLOC_USAGE_HW_RENDER;
+
+  framebuffer_target_ = std::make_shared<IonBuffer>(
+      native_display_metrics_.width, native_display_metrics_.height, format,
+      usage);
+
+  // Associate each Layer instance with a hardware composer layer.
+  for (auto layer : layers_) {
+    layer->Initialize(hwc2_hidl_.get(), &native_display_metrics_);
+  }
+
+  // Open the backlight brightness control sysfs node.
+  backlight_brightness_fd_ = LocalHandle(kBacklightBrightnessSysFile, O_RDWR);
+  ALOGW_IF(!backlight_brightness_fd_,
+           "HardwareComposer: Failed to open backlight brightness control: %s",
+           strerror(errno));
+
+  // Open the vsync event node for the primary display.
+  // TODO(eieio): Move this into a platform-specific class.
+  primary_display_vsync_event_fd_ =
+      LocalHandle(kPrimaryDisplayVSyncEventFile, O_RDONLY);
+  ALOGE_IF(!primary_display_vsync_event_fd_,
+           "HardwareComposer: Failed to open vsync event node for primary "
+           "display: %s",
+           strerror(errno));
+
+  // Open the wait pingpong status node for the primary display.
+  // TODO(eieio): Move this into a platform-specific class.
+  primary_display_wait_pp_fd_ =
+      LocalHandle(kPrimaryDisplayWaitPPEventFile, O_RDONLY);
+  ALOGE_IF(
+      !primary_display_wait_pp_fd_,
+      "HardwareComposer: Failed to open wait_pp node for primary display: %s",
+      strerror(errno));
+
+  // Create a timerfd based on CLOCK_MONOTINIC.
+  vsync_sleep_timer_fd_.Reset(timerfd_create(CLOCK_MONOTONIC, 0));
+  LOG_ALWAYS_FATAL_IF(
+      !vsync_sleep_timer_fd_,
+      "HardwareComposer: Failed to create vsync sleep timerfd: %s",
+      strerror(errno));
+
+  // Connect to pose service.
+  pose_client_ = dvrPoseCreate();
+  ALOGE_IF(!pose_client_, "HardwareComposer: Failed to create pose client");
+
+  // Variables used to control the post thread state
+  pause_post_thread_ = false;
+  terminate_post_thread_event_fd_.Reset(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK));
+
+  LOG_ALWAYS_FATAL_IF(
+      !terminate_post_thread_event_fd_,
+      "HardwareComposer: Failed to create terminate PostThread event fd : %s",
+      strerror(errno));
+
+  // If get_id() is the default thread::id object, it has not been created yet
+  if (post_thread_.get_id() == std::thread::id()) {
+    post_thread_ = std::thread(&HardwareComposer::PostThread, this);
+  } else {
+    UpdateDisplayState();
+    thread_pause_semaphore_.notify_one();
+  }
+
+  return true;
+}
+
+bool HardwareComposer::Suspend() {
+  // Wait for any pending layer operations to finish
+  std::unique_lock<std::mutex> layer_lock(layer_mutex_);
+
+  if (IsSuspended()) {
+    ALOGE("HardwareComposer::Suspend: HardwareComposer is already suspended.");
+    return false;
+  }
+
+  PausePostThread();
+
+  EnableVsync(false);
+  SetPowerMode(HWC_DISPLAY_PRIMARY, HWC2_POWER_MODE_OFF);
+
+  backlight_brightness_fd_.Close();
+  primary_display_vsync_event_fd_.Close();
+  primary_display_wait_pp_fd_.Close();
+  vsync_sleep_timer_fd_.Close();
+  retire_fence_fds_.clear();
+  gpu_layer_ = nullptr;
+
+  // We have to destroy the layers before we close the hwc device
+  for (size_t i = 0; i < kMaxHardwareLayers; ++i) {
+    layers_[i]->Reset();
+  }
+
+  active_layer_count_ = 0;
+
+  framebuffer_target_.reset();
+
+  //hwc2_hidl_.reset();
+
+  if (pose_client_)
+    dvrPoseDestroy(pose_client_);
+
+  return true;
+}
+
+void HardwareComposer::PausePostThread() {
+  pause_post_thread_ = true;
+
+  int error = eventfd_write(terminate_post_thread_event_fd_.Get(), 1);
+  ALOGE_IF(error,
+           "HardwareComposer::PausePostThread: could not write post "
+           "thread termination event fd : %d",
+           error);
+
+  std::unique_lock<std::mutex> wait_for_thread(thread_pause_mutex_);
+  terminate_post_thread_event_fd_.Close();
+}
+
+DisplayMetrics HardwareComposer::GetHmdDisplayMetrics() const {
+  vec2i screen_size(display_metrics_.width, display_metrics_.height);
+  DisplayOrientation orientation =
+      (display_metrics_.width > display_metrics_.height
+           ? DisplayOrientation::kLandscape
+           : DisplayOrientation::kPortrait);
+  float dpi_x = static_cast<float>(display_metrics_.dpi.x) / 1000.0f;
+  float dpi_y = static_cast<float>(display_metrics_.dpi.y) / 1000.0f;
+  float meters_per_pixel_x = kMetersPerInch / dpi_x;
+  float meters_per_pixel_y = kMetersPerInch / dpi_y;
+  vec2 meters_per_pixel(meters_per_pixel_x, meters_per_pixel_y);
+  double frame_duration_s =
+      static_cast<double>(display_metrics_.vsync_period_ns) / 1000000000.0;
+  // TODO(hendrikw): Hard coding to 3mm.  The Pixel is actually 4mm, but it
+  //                 seems that their tray to lens distance is wrong too, which
+  //                 offsets this, at least for the pixel.
+  float border_size = 0.003f;
+  return DisplayMetrics(screen_size, meters_per_pixel, border_size,
+                        static_cast<float>(frame_duration_s), orientation);
+}
+
+int32_t HardwareComposer::Validate(hwc2_display_t display) {
+  uint32_t num_types;
+  uint32_t num_requests;
+  int32_t error =
+      (int32_t)hwc2_hidl_->validateDisplay(display, &num_types, &num_requests);
+
+  if (error == HWC2_ERROR_HAS_CHANGES) {
+    // TODO(skiazyk): We might need to inspect the requested changes first, but
+    // so far it seems like we shouldn't ever hit a bad state.
+    // error = hwc2_funcs_.accept_display_changes_fn_(hardware_composer_device_,
+    //                                               display);
+    error = (int32_t)hwc2_hidl_->acceptDisplayChanges(display);
+  }
+
+  return error;
+}
+
+int32_t HardwareComposer::EnableVsync(bool enabled) {
+  return (int32_t)hwc2_hidl_->setVsyncEnabled(
+      HWC_DISPLAY_PRIMARY,
+      (Hwc2::IComposerClient::Vsync)(enabled ? HWC2_VSYNC_ENABLE
+                                             : HWC2_VSYNC_DISABLE));
+}
+
+int32_t HardwareComposer::Present(hwc2_display_t display) {
+  int32_t present_fence;
+  int32_t error = (int32_t)hwc2_hidl_->presentDisplay(display, &present_fence);
+
+  // According to the documentation, this fence is signaled at the time of
+  // vsync/DMA for physical displays.
+  if (error == HWC2_ERROR_NONE) {
+    ATRACE_INT("HardwareComposer: VsyncFence", present_fence);
+    retire_fence_fds_.emplace_back(present_fence);
+  } else {
+    ATRACE_INT("HardwareComposer: PresentResult", error);
+  }
+
+  return error;
+}
+
+int32_t HardwareComposer::SetPowerMode(hwc2_display_t display,
+                                       hwc2_power_mode_t mode) {
+  if (mode == HWC2_POWER_MODE_OFF) {
+    EnableVsync(false);
+  }
+
+  display_on_ = mode != HWC2_POWER_MODE_OFF;
+
+  return (int32_t)hwc2_hidl_->setPowerMode(
+      display, (Hwc2::IComposerClient::PowerMode)mode);
+}
+
+int32_t HardwareComposer::GetDisplayAttribute(hwc2_display_t display,
+                                              hwc2_config_t config,
+                                              hwc2_attribute_t attribute,
+                                              int32_t* out_value) const {
+  return (int32_t)hwc2_hidl_->getDisplayAttribute(
+      display, config, (Hwc2::IComposerClient::Attribute)attribute, out_value);
+}
+
+int32_t HardwareComposer::GetDisplayMetrics(
+    hwc2_display_t display, hwc2_config_t config,
+    HWCDisplayMetrics* out_metrics) const {
+  int32_t ret = HWC2_ERROR_NONE;
+
+  ret = GetDisplayAttribute(display, config, HWC2_ATTRIBUTE_WIDTH,
+                            &out_metrics->width);
+  if (ret != HWC2_ERROR_NONE) {
+    ALOGE("HardwareComposer: Failed to get display width");
+    return ret;
+  }
+
+  ret = GetDisplayAttribute(display, config, HWC2_ATTRIBUTE_HEIGHT,
+                            &out_metrics->height);
+  if (ret != HWC2_ERROR_NONE) {
+    ALOGE("HardwareComposer: Failed to get display height");
+    return ret;
+  }
+
+  ret = GetDisplayAttribute(display, config, HWC2_ATTRIBUTE_VSYNC_PERIOD,
+                            &out_metrics->vsync_period_ns);
+  if (ret != HWC2_ERROR_NONE) {
+    ALOGE("HardwareComposer: Failed to get display height");
+    return ret;
+  }
+
+  ret = GetDisplayAttribute(display, config, HWC2_ATTRIBUTE_DPI_X,
+                            &out_metrics->dpi.x);
+  if (ret != HWC2_ERROR_NONE) {
+    ALOGE("HardwareComposer: Failed to get display DPI X");
+    return ret;
+  }
+
+  ret = GetDisplayAttribute(display, config, HWC2_ATTRIBUTE_DPI_Y,
+                            &out_metrics->dpi.y);
+  if (ret != HWC2_ERROR_NONE) {
+    ALOGE("HardwareComposer: Failed to get display DPI Y");
+    return ret;
+  }
+
+  return HWC2_ERROR_NONE;
+}
+
+void HardwareComposer::Dump(char* buffer, uint32_t* out_size) {
+  std::string debug_str = hwc2_hidl_->dumpDebugInfo();
+  ALOGI("%s", debug_str.c_str());
+
+  if (buffer == nullptr) {
+    *out_size = debug_str.size();
+  } else {
+    std::copy(debug_str.begin(), debug_str.begin() + *out_size, buffer);
+  }
+}
+
+// TODO(skiazyk): Figure out what to do with `is_geometry_changed`. There does
+// not seem to be any equivalent in the HWC2 API, but that doesn't mean its not
+// there.
+void HardwareComposer::PostLayers(bool /*is_geometry_changed*/) {
+  ATRACE_NAME("HardwareComposer::PostLayers");
+
+  // Setup the hardware composer layers with current buffers.
+  for (size_t i = 0; i < active_layer_count_; i++) {
+    layers_[i]->Prepare();
+  }
+
+  // Now that we have taken in a frame from the application, we have a chance
+  // to drop the frame before passing the frame along to HWC.
+  // If the display driver has become backed up, we detect it here and then
+  // react by skipping this frame to catch up latency.
+  while (!retire_fence_fds_.empty() &&
+         (!retire_fence_fds_.front() ||
+          sync_wait(retire_fence_fds_.front().Get(), 0) == 0)) {
+    // There are only 2 fences in here, no performance problem to shift the
+    // array of ints.
+    retire_fence_fds_.erase(retire_fence_fds_.begin());
+  }
+
+  const bool is_frame_pending = IsFramePendingInDriver();
+  const bool is_fence_pending =
+      retire_fence_fds_.size() > kAllowedPendingFenceCount;
+
+  if (is_fence_pending || is_frame_pending) {
+    ATRACE_INT("frame_skip_count", ++frame_skip_count_);
+
+    ALOGW_IF(is_frame_pending, "Warning: frame already queued, dropping frame");
+    ALOGW_IF(is_fence_pending,
+             "Warning: dropping a frame to catch up with HWC (pending = %zd)",
+             retire_fence_fds_.size());
+
+    for (size_t i = 0; i < active_layer_count_; i++) {
+      layers_[i]->Drop();
+    }
+    return;
+  } else {
+    // Make the transition more obvious in systrace when the frame skip happens
+    // above.
+    ATRACE_INT("frame_skip_count", 0);
+  }
+
+#if TRACE
+  for (size_t i = 0; i < active_layer_count_; i++)
+    ALOGI("HardwareComposer::PostLayers: dl[%zu] ctype=0x%08x", i,
+          layers_[i]->GetCompositionType());
+#endif
+
+  int32_t ret = HWC2_ERROR_NONE;
+
+  std::vector<Hwc2::IComposerClient::Rect> full_region(1);
+  full_region[0].left = 0;
+  full_region[0].top = 0;
+  full_region[0].right = framebuffer_target_->width();
+  full_region[0].bottom = framebuffer_target_->height();
+
+  ALOGE_IF(ret, "Error setting client target : %d", ret);
+
+  ret = Validate(HWC_DISPLAY_PRIMARY);
+  if (ret) {
+    ALOGE("HardwareComposer::Validate failed; ret=%d", ret);
+    return;
+  }
+
+  ret = Present(HWC_DISPLAY_PRIMARY);
+  if (ret) {
+    ALOGE("HardwareComposer::Present failed; ret=%d", ret);
+    return;
+  }
+
+  std::vector<Hwc2::Layer> out_layers;
+  std::vector<int> out_fences;
+  ret = (int32_t)hwc2_hidl_->getReleaseFences(HWC_DISPLAY_PRIMARY, &out_layers,
+                                              &out_fences);
+  uint32_t num_elements = out_layers.size();
+
+  ALOGE_IF(ret, "HardwareComposer: GetReleaseFences failed; ret=%d", ret);
+
+  // Perform post-frame bookkeeping. Unused layers are a no-op.
+  for (size_t i = 0; i < num_elements; ++i) {
+    for (size_t j = 0; j < active_layer_count_; ++j) {
+      if (layers_[j]->GetLayerHandle() == out_layers[i]) {
+        layers_[j]->Finish(out_fences[i]);
+      }
+    }
+  }
+}
+
+// TODO(skiazyk): This is a work-around for the fact that we currently do not
+// handle the case when new surfaces are introduced when displayd is not
+// in an active state. A proper-solution will require re-structuring
+// displayd a little, but hopefully this is sufficient for now.
+// For example, could this be handled in |UpdateLayerSettings| instead?
+void HardwareComposer::UpdateDisplayState() {
+  const bool has_display_surfaces = display_surfaces_.size() > 0;
+
+  if (has_display_surfaces) {
+    int32_t ret = SetPowerMode(HWC_DISPLAY_PRIMARY, HWC2_POWER_MODE_ON);
+
+    ALOGE_IF(ret, "HardwareComposer: Could not set power mode; ret=%d", ret);
+
+    EnableVsync(true);
+  }
+  // TODO(skiazyk): We need to do something about accessing this directly,
+  // supposedly there is a backlight service on the way.
+  SetBacklightBrightness(255);
+
+  if (!display_on_ && has_display_surfaces) {
+    const int error = ReadVSyncTimestamp(&last_vsync_timestamp_);
+    ALOGE_IF(error < 0,
+             "HardwareComposer::SetDisplaySurfaces: Failed to read vsync "
+             "timestamp: %s",
+             strerror(-error));
+  }
+
+  // Trigger target-specific performance mode change.
+  property_set(kDvrPerformanceProperty, display_on_ ? "performance" : "idle");
+}
+
+int HardwareComposer::SetDisplaySurfaces(
+    std::vector<std::shared_ptr<DisplaySurface>> surfaces) {
+  std::lock_guard<std::mutex> autolock(layer_mutex_);
+
+  ALOGI("HardwareComposer::SetDisplaySurfaces: surface count=%zd",
+        surfaces.size());
+
+  // Figure out whether we need to update hardware layers. If this surface
+  // change does not add or remove hardware layers we can avoid display hiccups
+  // by gracefully updating only the GPU compositor layers.
+  // hardware_layers_need_update_ is reset to false by the Post thread.
+  int old_gpu_layer_count = 0;
+  int new_gpu_layer_count = 0;
+  // Look for new hardware layers and count new GPU layers.
+  for (const auto& surface : surfaces) {
+    if (!(surface->flags() &
+          DVR_DISPLAY_SURFACE_FLAGS_DISABLE_SYSTEM_DISTORTION))
+      ++new_gpu_layer_count;
+    else if (std::find(display_surfaces_.begin(), display_surfaces_.end(),
+                       surface) == display_surfaces_.end())
+      // This is a new hardware layer, we need to update.
+      hardware_layers_need_update_ = true;
+  }
+  // Look for deleted hardware layers or compositor layers.
+  for (const auto& surface : display_surfaces_) {
+    if (!(surface->flags() &
+          DVR_DISPLAY_SURFACE_FLAGS_DISABLE_SYSTEM_DISTORTION))
+      ++old_gpu_layer_count;
+    else if (std::find(surfaces.begin(), surfaces.end(), surface) ==
+             surfaces.end())
+      // This is a deleted hardware layer, we need to update.
+      hardware_layers_need_update_ = true;
+  }
+  // Check for compositor hardware layer transition.
+  if ((!old_gpu_layer_count && new_gpu_layer_count) ||
+      (old_gpu_layer_count && !new_gpu_layer_count))
+    hardware_layers_need_update_ = true;
+
+  display_surfaces_ = std::move(surfaces);
+  display_surfaces_updated_ = true;
+
+  // Set the chosen layer order for all surfaces.
+  for (size_t i = 0; i < display_surfaces_.size(); ++i) {
+    display_surfaces_[i]->SetLayerOrder(static_cast<int>(i));
+  }
+
+  // TODO(skiazyk): fix this so that it is handled seamlessly with dormant/non-
+  // dormant state.
+  if (!IsSuspended()) {
+    UpdateDisplayState();
+  }
+
+  return 0;
+}
+
+// Reads the value of the display driver wait_pingpong state. Returns 0 or 1
+// (the value of the state) on success or a negative error otherwise.
+// TODO(eieio): This is pretty driver specific, this should be moved to a
+// separate class eventually.
+int HardwareComposer::ReadWaitPPState() {
+  // Gracefully handle when the kernel does not support this feature.
+  if (!primary_display_wait_pp_fd_)
+    return 0;
+
+  const int wait_pp_fd = primary_display_wait_pp_fd_.Get();
+  int ret, error;
+
+  ret = lseek(wait_pp_fd, 0, SEEK_SET);
+  if (ret < 0) {
+    error = errno;
+    ALOGE("HardwareComposer::ReadWaitPPState: Failed to seek wait_pp fd: %s",
+          strerror(error));
+    return -error;
+  }
+
+  char data = -1;
+  ret = read(wait_pp_fd, &data, sizeof(data));
+  if (ret < 0) {
+    error = errno;
+    ALOGE("HardwareComposer::ReadWaitPPState: Failed to read wait_pp state: %s",
+          strerror(error));
+    return -error;
+  }
+
+  switch (data) {
+    case '0':
+      return 0;
+    case '1':
+      return 1;
+    default:
+      ALOGE(
+          "HardwareComposer::ReadWaitPPState: Unexpected value for wait_pp: %d",
+          data);
+      return -EINVAL;
+  }
+}
+
+// Reads the timestamp of the last vsync from the display driver.
+// TODO(eieio): This is pretty driver specific, this should be moved to a
+// separate class eventually.
+int HardwareComposer::ReadVSyncTimestamp(int64_t* timestamp) {
+  const int event_fd = primary_display_vsync_event_fd_.Get();
+  int ret, error;
+
+  // The driver returns data in the form "VSYNC=<timestamp ns>".
+  std::array<char, 32> data;
+  data.fill('\0');
+
+  // Seek back to the beginning of the event file.
+  ret = lseek(event_fd, 0, SEEK_SET);
+  if (ret < 0) {
+    error = errno;
+    ALOGE(
+        "HardwareComposer::ReadVSyncTimestamp: Failed to seek vsync event fd: "
+        "%s",
+        strerror(error));
+    return -error;
+  }
+
+  // Read the vsync event timestamp.
+  ret = read(event_fd, data.data(), data.size());
+  if (ret < 0) {
+    error = errno;
+    ALOGE_IF(
+        error != EAGAIN,
+        "HardwareComposer::ReadVSyncTimestamp: Error while reading timestamp: "
+        "%s",
+        strerror(error));
+    return -error;
+  }
+
+  ret = sscanf(data.data(), "VSYNC=%" PRIu64,
+               reinterpret_cast<uint64_t*>(timestamp));
+  if (ret < 0) {
+    error = errno;
+    ALOGE(
+        "HardwareComposer::ReadVSyncTimestamp: Error while parsing timestamp: "
+        "%s",
+        strerror(error));
+    return -error;
+  }
+
+  return 0;
+}
+
+// Blocks until the next vsync event is signaled by the display driver.
+// TODO(eieio): This is pretty driver specific, this should be moved to a
+// separate class eventually.
+int HardwareComposer::BlockUntilVSync() {
+  const int event_fd = primary_display_vsync_event_fd_.Get();
+  pollfd pfd[2] = {
+      {
+          .fd = event_fd, .events = POLLPRI, .revents = 0,
+      },
+      // This extra event fd is to ensure that we can break out of this loop to
+      // pause the thread even when vsync is disabled, and thus no events on the
+      // vsync fd are being generated.
+      {
+          .fd = terminate_post_thread_event_fd_.Get(),
+          .events = POLLPRI | POLLIN,
+          .revents = 0,
+      },
+  };
+  int ret, error;
+  do {
+    ret = poll(pfd, 2, -1);
+    error = errno;
+    ALOGW_IF(ret < 0,
+             "HardwareComposer::BlockUntilVSync: Error while waiting for vsync "
+             "event: %s (%d)",
+             strerror(error), error);
+  } while (ret < 0 && error == EINTR);
+
+  return ret < 0 ? -error : 0;
+}
+
+// Waits for the next vsync and returns the timestamp of the vsync event. If
+// vsync already passed since the last call, returns the latest vsync timestamp
+// instead of blocking. This method updates the last_vsync_timeout_ in the
+// process.
+//
+// TODO(eieio): This is pretty driver specific, this should be moved to a
+// separate class eventually.
+int HardwareComposer::WaitForVSync(int64_t* timestamp) {
+  int error;
+
+  // Get the current timestamp and decide what to do.
+  while (true) {
+    int64_t current_vsync_timestamp;
+    error = ReadVSyncTimestamp(&current_vsync_timestamp);
+    if (error < 0 && error != -EAGAIN)
+      return error;
+
+    if (error == -EAGAIN) {
+      // Vsync was turned off, wait for the next vsync event.
+      error = BlockUntilVSync();
+      if (error < 0)
+        return error;
+
+      // If a request to pause the post thread was given, exit immediately
+      if (IsSuspended()) {
+        return 0;
+      }
+
+      // Try again to get the timestamp for this new vsync interval.
+      continue;
+    }
+
+    // Check that we advanced to a later vsync interval.
+    if (TimestampGT(current_vsync_timestamp, last_vsync_timestamp_)) {
+      *timestamp = last_vsync_timestamp_ = current_vsync_timestamp;
+      return 0;
+    }
+
+    // See how close we are to the next expected vsync. If we're within 1ms,
+    // sleep for 1ms and try again.
+    const int64_t ns_per_frame = display_metrics_.vsync_period_ns;
+    const int64_t threshold_ns = 1000000;
+
+    const int64_t next_vsync_est = last_vsync_timestamp_ + ns_per_frame;
+    const int64_t distance_to_vsync_est = next_vsync_est - GetSystemClockNs();
+
+    if (distance_to_vsync_est > threshold_ns) {
+      // Wait for vsync event notification.
+      error = BlockUntilVSync();
+      if (error < 0)
+        return error;
+
+      // Again, exit immediately if the thread was requested to pause
+      if (IsSuspended()) {
+        return 0;
+      }
+    } else {
+      // Sleep for a short time before retrying.
+      std::this_thread::sleep_for(std::chrono::milliseconds(1));
+    }
+  }
+}
+
+int HardwareComposer::SleepUntil(int64_t wakeup_timestamp) {
+  const int timer_fd = vsync_sleep_timer_fd_.Get();
+  const itimerspec wakeup_itimerspec = {
+      .it_interval = {.tv_sec = 0, .tv_nsec = 0},
+      .it_value = NsToTimespec(wakeup_timestamp),
+  };
+  int ret =
+      timerfd_settime(timer_fd, TFD_TIMER_ABSTIME, &wakeup_itimerspec, nullptr);
+  int error = errno;
+  if (ret < 0) {
+    ALOGE("HardwareComposer::SleepUntil: Failed to set timerfd: %s",
+          strerror(error));
+    return -error;
+  }
+
+  // Wait for the timer by reading the expiration count.
+  uint64_t expiration_count;
+  ret = read(timer_fd, &expiration_count, sizeof(expiration_count));
+  if (ret < 0) {
+    ALOGE("HardwareComposer::SleepUntil: Failed to wait for timerfd: %s",
+          strerror(error));
+    return -error;
+  }
+
+  return 0;
+}
+
+void HardwareComposer::PostThread() {
+  // NOLINTNEXTLINE(runtime/int)
+  prctl(PR_SET_NAME, reinterpret_cast<unsigned long>("PostThread"), 0, 0, 0);
+
+  std::unique_lock<std::mutex> thread_lock(thread_pause_mutex_);
+
+  // Set the scheduler to SCHED_FIFO with high priority.
+  int error = dvrSetSchedulerClass(0, "graphics:high");
+  LOG_ALWAYS_FATAL_IF(
+      error < 0,
+      "HardwareComposer::PostThread: Failed to set scheduler class: %s",
+      strerror(-error));
+  error = dvrSetCpuPartition(0, "/system/performance");
+  LOG_ALWAYS_FATAL_IF(
+      error < 0,
+      "HardwareComposer::PostThread: Failed to set cpu partition: %s",
+      strerror(-error));
+
+  // Force the layers to be setup at least once.
+  display_surfaces_updated_ = true;
+
+  // Initialize the GPU compositor.
+  LOG_ALWAYS_FATAL_IF(!compositor_.Initialize(GetHmdDisplayMetrics()),
+                      "Failed to initialize the compositor");
+
+  const int64_t ns_per_frame = display_metrics_.vsync_period_ns;
+  const int64_t photon_offset_ns = GetPosePredictionTimeOffset(ns_per_frame);
+
+  // TODO(jbates) Query vblank time from device, when such an API is available.
+  // This value (6.3%) was measured on A00 in low persistence mode.
+  int64_t vblank_ns = ns_per_frame * 63 / 1000;
+  int64_t right_eye_photon_offset_ns = (ns_per_frame - vblank_ns) / 2;
+
+  // Check property for overriding right eye offset value.
+  right_eye_photon_offset_ns =
+      property_get_int64(kRightEyeOffsetProperty, right_eye_photon_offset_ns);
+
+  // The list of surfaces the compositor should attempt to render. This is set
+  // at the start of each frame.
+  std::vector<std::shared_ptr<DisplaySurface>> compositor_surfaces;
+  compositor_surfaces.reserve(2);
+
+  // Our history of frame times. This is used to get a better estimate of how
+  // long the next frame will take, to set a schedule for EDS.
+  FrameTimeHistory frame_time_history;
+
+  // The backlog is used to allow us to start rendering the next frame before
+  // the previous frame has finished, and still get an accurate measurement of
+  // frame duration.
+  std::vector<FrameTimeMeasurementRecord> frame_time_backlog;
+  constexpr int kFrameTimeBacklogMax = 2;
+  frame_time_backlog.reserve(kFrameTimeBacklogMax);
+
+  // Storage for retrieving fence info.
+  FenceInfoBuffer fence_info_buffer;
+
+  while (1) {
+    ATRACE_NAME("HardwareComposer::PostThread");
+
+    while (IsSuspended()) {
+      ALOGI("HardwareComposer::PostThread: Post thread pause requested.");
+      thread_pause_semaphore_.wait(thread_lock);
+      // The layers will need to be updated since they were deleted previously
+      display_surfaces_updated_ = true;
+      hardware_layers_need_update_ = true;
+    }
+
+    int64_t vsync_timestamp = 0;
+    {
+      std::array<char, 128> buf;
+      snprintf(buf.data(), buf.size(), "wait_vsync|vsync=%d|",
+               vsync_count_ + 1);
+      ATRACE_NAME(buf.data());
+
+      error = WaitForVSync(&vsync_timestamp);
+      ALOGE_IF(
+          error < 0,
+          "HardwareComposer::PostThread: Failed to wait for vsync event: %s",
+          strerror(-error));
+
+      // Don't bother processing this frame if a pause was requested
+      if (IsSuspended()) {
+        continue;
+      }
+    }
+
+    ++vsync_count_;
+
+    static double last_print_time = -1;
+    double current_time = GetSystemClockSec();
+    if (last_print_time < 0 || current_time - last_print_time > 3) {
+      last_print_time = current_time;
+    }
+
+    if (pose_client_) {
+      // Signal the pose service with vsync info.
+      // Display timestamp is in the middle of scanout.
+      privateDvrPoseNotifyVsync(pose_client_, vsync_count_,
+                                vsync_timestamp + photon_offset_ns,
+                                ns_per_frame, right_eye_photon_offset_ns);
+    }
+
+    bool layer_config_changed = UpdateLayerConfig(&compositor_surfaces);
+
+    if (layer_config_changed) {
+      frame_time_history.ResetWithSeed(
+          GuessFrameTime(compositor_surfaces.size()));
+      frame_time_backlog.clear();
+    } else {
+      UpdateFrameTimeHistory(&frame_time_backlog, kFrameTimeBacklogMax,
+                             &fence_info_buffer, &frame_time_history);
+    }
+
+    // Get our current best estimate at how long the next frame will take to
+    // render, based on how long previous frames took to render. Use this
+    // estimate to decide when to wake up for EDS.
+    int64_t frame_time_estimate =
+        frame_time_history.GetSampleCount() == 0
+            ? GuessFrameTime(compositor_surfaces.size())
+            : frame_time_history.GetAverage();
+    frame_time_estimate = std::max(frame_time_estimate, kFrameTimeEstimateMin);
+    DebugHudData::data.hwc_latency = frame_time_estimate;
+
+    // Signal all of the vsync clients. Because absolute time is used for the
+    // wakeup time below, this can take a little time if necessary.
+    if (vsync_callback_)
+      vsync_callback_(HWC_DISPLAY_PRIMARY, vsync_timestamp, frame_time_estimate,
+                      vsync_count_);
+
+    {
+      // Sleep until async EDS wakeup time.
+      ATRACE_NAME("sleep");
+
+      int64_t display_time_est = vsync_timestamp + ns_per_frame;
+      int64_t now = GetSystemClockNs();
+      int64_t frame_finish_time_est = now + frame_time_estimate;
+      int64_t sleep_time_ns = display_time_est - now - frame_time_estimate;
+
+      ATRACE_INT64("sleep_time_ns", sleep_time_ns);
+      if (frame_finish_time_est - display_time_est >= kFrameSkipThresholdNs) {
+        ATRACE_INT("frame_skip_count", ++frame_skip_count_);
+        ALOGE(
+            "HardwareComposer::PostThread: Missed frame schedule, drop "
+            "frame. Expected frame miss: %.1fms",
+            static_cast<double>(frame_finish_time_est - display_time_est) /
+                1000000);
+
+        // There are several reasons we might skip a frame, but one possibility
+        // is we mispredicted the frame time. Clear out the frame time history.
+        frame_time_history.ResetWithSeed(
+            GuessFrameTime(compositor_surfaces.size()));
+        frame_time_backlog.clear();
+        DebugHudData::data.hwc_frame_stats.SkipFrame();
+
+        continue;
+      } else {
+        // Make the transition more obvious in systrace when the frame skip
+        // happens above.
+        ATRACE_INT("frame_skip_count", 0);
+      }
+
+      if (sleep_time_ns > 0) {
+        error = SleepUntil(display_time_est - frame_time_estimate);
+        ALOGE_IF(error < 0, "HardwareComposer::PostThread: Failed to sleep: %s",
+                 strerror(-error));
+      }
+    }
+
+    DebugHudData::data.hwc_frame_stats.AddFrame();
+
+    int64_t frame_start_time = GetSystemClockNs();
+
+    // Setup the output buffer for the compositor. This needs to happen before
+    // you draw with the compositor.
+    if (gpu_layer_ != nullptr) {
+      gpu_layer_->UpdateDirectBuffer(compositor_.GetBuffer());
+    }
+
+    // Call PostLayers now before performing the GL code for the compositor to
+    // avoid missing the deadline that can cause the lower-level hwc to get
+    // permanently backed up.
+    PostLayers(layer_config_changed);
+
+    PostCompositorBuffers(compositor_surfaces);
+
+    if (gpu_layer_ != nullptr) {
+      // Note, with scanline racing, this draw is timed along with the post
+      // layers to finish just in time.
+      LocalHandle frame_fence_fd;
+      compositor_.DrawFrame(vsync_count_ + 1, &frame_fence_fd);
+      if (frame_fence_fd) {
+        LOG_ALWAYS_FATAL_IF(frame_time_backlog.size() >= kFrameTimeBacklogMax,
+                            "Frame time backlog exceeds capacity");
+        frame_time_backlog.push_back(
+            {frame_start_time, std::move(frame_fence_fd)});
+      }
+    } else if (!layer_config_changed) {
+      frame_time_history.AddSample(GetSystemClockNs() - frame_start_time);
+    }
+
+    HandlePendingScreenshots();
+  }
+
+  // TODO(skiazyk): Currently the compositor is not fully releasing its EGL
+  // context, which seems to prevent the thread from exiting properly.
+  // This shouldn't be too hard to address, I just don't have time right now.
+  compositor_.Shutdown();
+}
+
+bool HardwareComposer::UpdateLayerConfig(
+    std::vector<std::shared_ptr<DisplaySurface>>* compositor_surfaces) {
+  std::lock_guard<std::mutex> autolock(layer_mutex_);
+
+  if (!display_surfaces_updated_)
+    return false;
+
+  display_surfaces_updated_ = false;
+  DebugHudData::data.ResetLayers();
+
+  // Update compositor layers.
+  {
+    ATRACE_NAME("UpdateLayerConfig_GpuLayers");
+    compositor_.UpdateSurfaces(display_surfaces_);
+    compositor_surfaces->clear();
+    for (size_t i = 0; i < display_surfaces_.size(); ++i) {
+      const auto& surface = display_surfaces_[i];
+      if (!(surface->flags() &
+            DVR_DISPLAY_SURFACE_FLAGS_DISABLE_SYSTEM_DISTORTION)) {
+        compositor_surfaces->push_back(surface);
+      }
+    }
+  }
+
+  if (!hardware_layers_need_update_)
+    return true;
+
+  // Update hardware layers.
+
+  ATRACE_NAME("UpdateLayerConfig_HwLayers");
+  hardware_layers_need_update_ = false;
+
+  // Update the display layers in a non-destructive fashion.
+
+  // Create a map from surface id to hardware layer
+  std::map<int, Layer*> display_surface_layers;
+
+  for (size_t i = 0; i < active_layer_count_; ++i) {
+    auto layer = layers_[i];
+    int surface_id = layer->GetSurfaceId();
+
+    auto found =
+        std::find_if(display_surfaces_.begin(), display_surfaces_.end(),
+                     [surface_id](const auto& surface) {
+                       return surface->surface_id() == surface_id;
+                     });
+
+    if (found != display_surfaces_.end()) {
+      display_surface_layers[surface_id] = layer;
+    }
+  }
+
+  bool has_gpu_layer = std::any_of(
+      display_surfaces_.begin(), display_surfaces_.end(),
+      [](const auto& surface) {
+        return !(surface->flags() &
+                 DVR_DISPLAY_SURFACE_FLAGS_DISABLE_SYSTEM_DISTORTION);
+      });
+
+  if (!has_gpu_layer) {
+    gpu_layer_ = nullptr;
+  }
+
+  auto is_layer_active = [&display_surface_layers, has_gpu_layer](auto layer) {
+    int surface_id = layer->GetSurfaceId();
+    if (surface_id >= 0) {
+      return display_surface_layers.count(surface_id) > 0;
+    } else {
+      return has_gpu_layer;
+    }
+  };
+
+  // Compress the in-use layers to the top of the list
+  auto part = std::partition(
+      layers_.begin(), layers_.begin() + active_layer_count_, is_layer_active);
+
+  size_t new_active_layer_count = part - layers_.begin();
+
+  // Clear any unused layers
+  for (size_t i = new_active_layer_count; i < active_layer_count_; ++i) {
+    layers_[i]->Reset();
+  }
+
+  active_layer_count_ = new_active_layer_count;
+
+  bool gpu_layer_applied = false;
+
+  // Create/update all of the hardware layers
+  for (size_t i = 0; i < display_surfaces_.size(); ++i) {
+    const auto& surface = display_surfaces_[i];
+    bool is_hw_surface =
+        surface->flags() & DVR_DISPLAY_SURFACE_FLAGS_DISABLE_SYSTEM_DISTORTION;
+    hwc2_blend_mode_t blending =
+        i == 0 ? HWC2_BLEND_MODE_NONE : HWC2_BLEND_MODE_COVERAGE;
+
+    DebugHudData::data.SetLayerInfo(
+        i, surface->width(), surface->height(),
+        !!(surface->flags() & DVR_DISPLAY_SURFACE_FLAGS_GEOMETRY_SEPARATE_2));
+
+    if (!is_hw_surface && gpu_layer_applied) {
+      continue;
+    }
+
+    Layer* target_layer;
+    bool existing_layer = false;
+
+    if (is_hw_surface) {
+      auto it = display_surface_layers.find(surface->surface_id());
+
+      if (it != display_surface_layers.end()) {
+        target_layer = it->second;
+        existing_layer = true;
+      }
+    } else if (gpu_layer_ != nullptr) {
+      target_layer = gpu_layer_;
+      existing_layer = true;
+    }
+
+    if (!existing_layer) {
+      if (active_layer_count_ >= kMaxHardwareLayers) {
+        ALOGI("HardwareComposer: More than %d hardware layers requested.",
+              kMaxHardwareLayers);
+        break;
+      } else {
+        target_layer = layers_[active_layer_count_];
+        ++active_layer_count_;
+      }
+
+      ALOGD_IF(TRACE,
+               "HardwareComposer::UpdateLayerConfig: (new) surface_id=%d -> "
+               "layer=%zd",
+               surface->surface_id(), i);
+
+      if (is_hw_surface) {
+        target_layer->Setup(surface, blending, display_transform_,
+                            HWC2_COMPOSITION_DEVICE, i);
+      } else {
+        gpu_layer_ = target_layer;
+        target_layer->Setup(compositor_.GetBuffer(), blending,
+                            display_transform_, HWC2_COMPOSITION_DEVICE, i);
+      }
+    } else {
+      ALOGD_IF(TRACE,
+               "HardwareComposer::UpdateLayerConfig: (retained) surface_id=%d "
+               "-> layer=%zd",
+               surface->surface_id(), i);
+
+      target_layer->SetBlending(blending);
+      target_layer->SetZOrderIndex(i);
+      target_layer->UpdateLayerSettings();
+    }
+
+    gpu_layer_applied = !is_hw_surface;
+  }
+
+  ALOGD_IF(TRACE, "HardwareComposer::UpdateLayerConfig: %zd active layers",
+           active_layer_count_);
+
+  return true;
+}
+
+void HardwareComposer::PostCompositorBuffers(
+    const std::vector<std::shared_ptr<DisplaySurface>>& compositor_surfaces) {
+  ATRACE_NAME("PostCompositorBuffers");
+  for (const auto& surface : compositor_surfaces) {
+    compositor_.PostBuffer(surface);
+  }
+}
+
+void HardwareComposer::UpdateFrameTimeHistory(
+    std::vector<FrameTimeMeasurementRecord>* backlog, int backlog_max,
+    FenceInfoBuffer* fence_info_buffer, FrameTimeHistory* history) {
+  while (!backlog->empty()) {
+    const auto& frame_time_record = backlog->front();
+    int64_t end_time = 0;
+    bool frame_finished = CheckFrameFinished(frame_time_record.fence.Get(),
+                                             fence_info_buffer, &end_time);
+    if (frame_finished) {
+      int64_t frame_duration = end_time - frame_time_record.start_time;
+      history->AddSample(frame_duration);
+      // Our backlog is tiny (2 elements), so erasing from the front is ok
+      backlog->erase(backlog->begin());
+    } else {
+      break;
+    }
+  }
+
+  if (backlog->size() == static_cast<size_t>(backlog_max)) {
+    // Yikes, something must've gone wrong if our oldest frame hasn't finished
+    // yet. Give up on waiting for it.
+    const auto& stale_frame_time_record = backlog->front();
+    int64_t frame_duration =
+        GetSystemClockNs() - stale_frame_time_record.start_time;
+    backlog->erase(backlog->begin());
+    history->AddSample(frame_duration);
+    ALOGW("Frame didn't finish after %.1fms",
+          static_cast<double>(frame_duration) / 1000000);
+  }
+}
+
+bool HardwareComposer::CheckFrameFinished(int frame_fence_fd,
+                                          FenceInfoBuffer* fence_info_buffer,
+                                          int64_t* timestamp) {
+  int result = -1;
+  int sync_result = sync_wait(frame_fence_fd, 0);
+  if (sync_result == 0) {
+    result =
+        GetFenceSignaledTimestamp(frame_fence_fd, fence_info_buffer, timestamp);
+    if (result < 0) {
+      ALOGE("Failed getting signaled timestamp from fence");
+    }
+  } else if (errno != ETIME) {
+    ALOGE("sync_wait on frame fence failed");
+  }
+  return result >= 0;
+}
+
+void HardwareComposer::HandlePendingScreenshots() {
+  // Take a screenshot of the requested layer, if available.
+  // TODO(eieio): Look into using virtual displays to composite the layer stack
+  // into a single output buffer that can be returned to the screenshot clients.
+  if (active_layer_count_ > 0) {
+    if (auto screenshot_service = ScreenshotService::GetInstance()) {
+      if (screenshot_service->IsScreenshotRequestPending()) {
+        ATRACE_NAME("screenshot");
+        screenshot_service->TakeIfNeeded(layers_, compositor_);
+      }
+    } else {
+      ALOGW(
+          "HardwareComposer::HandlePendingScreenshots: Failed to get "
+          "screenshot service!");
+    }
+  }
+}
+
+void HardwareComposer::SetVSyncCallback(VSyncCallback callback) {
+  vsync_callback_ = callback;
+}
+
+void HardwareComposer::HwcRefresh(hwc2_callback_data_t /*data*/,
+                                  hwc2_display_t /*display*/) {
+  // TODO(eieio): implement invalidate callbacks.
+}
+
+void HardwareComposer::HwcVSync(hwc2_callback_data_t /*data*/,
+                                hwc2_display_t /*display*/,
+                                int64_t /*timestamp*/) {
+  ATRACE_NAME(__PRETTY_FUNCTION__);
+  // Intentionally empty. HWC may require a callback to be set to enable vsync
+  // signals. We bypass this callback thread by monitoring the vsync event
+  // directly, but signals still need to be enabled.
+}
+
+void HardwareComposer::HwcHotplug(hwc2_callback_data_t /*callbackData*/,
+                                  hwc2_display_t /*display*/,
+                                  hwc2_connection_t /*connected*/) {
+  // TODO(eieio): implement display hotplug callbacks.
+}
+
+void HardwareComposer::SetBacklightBrightness(int brightness) {
+  if (backlight_brightness_fd_) {
+    std::array<char, 32> text;
+    const int length = snprintf(text.data(), text.size(), "%d", brightness);
+    write(backlight_brightness_fd_.Get(), text.data(), length);
+  }
+}
+
+Layer::Layer()
+    : hwc2_hidl_(nullptr),
+      surface_index_(-1),
+      hardware_composer_layer_(0),
+      display_metrics_(nullptr),
+      blending_(HWC2_BLEND_MODE_NONE),
+      transform_(HWC_TRANSFORM_NONE),
+      composition_type_(HWC2_COMPOSITION_DEVICE),
+      surface_rect_functions_applied_(false) {}
+
+void Layer::Initialize(Hwc2::Composer* hwc2_hidl, HWCDisplayMetrics* metrics) {
+  hwc2_hidl_ = hwc2_hidl;
+  display_metrics_ = metrics;
+}
+
+void Layer::Reset() {
+  const int ret = acquired_buffer_.Release(std::move(release_fence_));
+  ALOGE_IF(ret < 0, "Layer::Reset: failed to release buffer: %s",
+           strerror(-ret));
+
+  if (hwc2_hidl_ != nullptr && hardware_composer_layer_) {
+    hwc2_hidl_->destroyLayer(HWC_DISPLAY_PRIMARY, hardware_composer_layer_);
+    hardware_composer_layer_ = 0;
+  }
+
+  surface_index_ = static_cast<size_t>(-1);
+  blending_ = HWC2_BLEND_MODE_NONE;
+  transform_ = HWC_TRANSFORM_NONE;
+  composition_type_ = HWC2_COMPOSITION_DEVICE;
+  direct_buffer_ = nullptr;
+  surface_ = nullptr;
+  acquire_fence_fd_.Close();
+  surface_rect_functions_applied_ = false;
+}
+
+void Layer::Setup(const std::shared_ptr<DisplaySurface>& surface,
+                  hwc2_blend_mode_t blending, hwc_transform_t transform,
+                  hwc2_composition_t composition_type, size_t index) {
+  Reset();
+  surface_index_ = index;
+  surface_ = surface;
+  blending_ = blending;
+  transform_ = transform;
+  composition_type_ = composition_type;
+  CommonLayerSetup();
+}
+
+void Layer::Setup(const std::shared_ptr<IonBuffer>& buffer,
+                  hwc2_blend_mode_t blending, hwc_transform_t transform,
+                  hwc2_composition_t composition_type, size_t z_order) {
+  Reset();
+  surface_index_ = z_order;
+  direct_buffer_ = buffer;
+  blending_ = blending;
+  transform_ = transform;
+  composition_type_ = composition_type;
+  CommonLayerSetup();
+}
+
+void Layer::UpdateDirectBuffer(const std::shared_ptr<IonBuffer>& buffer) {
+  direct_buffer_ = buffer;
+}
+
+void Layer::SetBlending(hwc2_blend_mode_t blending) { blending_ = blending; }
+
+void Layer::SetZOrderIndex(int z_index) { surface_index_ = z_index; }
+
+IonBuffer* Layer::GetBuffer() {
+  if (direct_buffer_)
+    return direct_buffer_.get();
+  else if (acquired_buffer_.IsAvailable())
+    return acquired_buffer_.buffer()->buffer();
+  else
+    return nullptr;
+}
+
+void Layer::UpdateLayerSettings() {
+  if (!IsLayerSetup()) {
+    ALOGE("HardwareComposer: Trying to update layers data on an unused layer.");
+    return;
+  }
+
+  int32_t ret = HWC2_ERROR_NONE;
+
+  hwc2_display_t display = HWC_DISPLAY_PRIMARY;
+
+  ret = (int32_t)hwc2_hidl_->setLayerCompositionType(
+      display, hardware_composer_layer_,
+      (Hwc2::IComposerClient::Composition)composition_type_);
+  ALOGE_IF(ret, "HardwareComposer: Error setting layer composition type : %d",
+           ret);
+  // ret = (int32_t) hwc2_hidl_->setLayerTransform(display,
+  // hardware_composer_layer_,
+  //                                    (Hwc2::IComposerClient::Transform)
+  //                                    transform_);
+  // ALOGE_IF(ret, "HardwareComposer: Error setting layer transform : %d", ret);
+
+  // ret = hwc2_funcs_->set_layer_blend_mode_fn_(
+  //    hardware_composer_device_, display, hardware_composer_layer_,
+  //    blending_);
+  ret = (int32_t)hwc2_hidl_->setLayerBlendMode(
+      display, hardware_composer_layer_,
+      (Hwc2::IComposerClient::BlendMode)blending_);
+  ALOGE_IF(ret, "HardwareComposer: Error setting layer blend mode : %d", ret);
+
+  Hwc2::IComposerClient::Rect display_frame;
+  display_frame.left = 0;
+  display_frame.top = 0;
+  display_frame.right = display_metrics_->width;
+  display_frame.bottom = display_metrics_->height;
+  ret = (int32_t)hwc2_hidl_->setLayerDisplayFrame(
+      display, hardware_composer_layer_, display_frame);
+  ALOGE_IF(ret, "HardwareComposer: Error setting layer display frame : %d",
+           ret);
+
+  std::vector<Hwc2::IComposerClient::Rect> visible_region(1);
+  visible_region[0] = display_frame;
+  ret = (int32_t)hwc2_hidl_->setLayerVisibleRegion(
+      display, hardware_composer_layer_, visible_region);
+  ALOGE_IF(ret, "HardwareComposer: Error setting layer visible region : %d",
+           ret);
+
+  ret = (int32_t)hwc2_hidl_->setLayerPlaneAlpha(display,
+                                                hardware_composer_layer_, 1.0f);
+  ALOGE_IF(ret, "HardwareComposer: Error setting layer plane alpha : %d", ret);
+
+  ret = (int32_t)hwc2_hidl_->setLayerZOrder(display, hardware_composer_layer_,
+                                            surface_index_);
+  ALOGE_IF(ret, "HardwareComposer: Error, setting z order index : %d", ret);
+}
+
+void Layer::CommonLayerSetup() {
+  int32_t ret = (int32_t)hwc2_hidl_->createLayer(HWC_DISPLAY_PRIMARY,
+                                                 &hardware_composer_layer_);
+
+  ALOGE_IF(ret,
+           "HardwareComposer: Failed to create layer on primary display : %d",
+           ret);
+
+  UpdateLayerSettings();
+}
+
+void Layer::Prepare() {
+  int right, bottom;
+  buffer_handle_t handle;
+
+  if (surface_) {
+    // Only update the acquired buffer when one is either available or this is
+    // the first time through.
+    if (surface_->IsBufferAvailable()) {
+      // If we previously set this to a solid color layer to stall for time,
+      // revert it to a device layer.
+      if (acquired_buffer_.IsEmpty() &&
+          composition_type_ != HWC2_COMPOSITION_DEVICE) {
+        composition_type_ = HWC2_COMPOSITION_DEVICE;
+        hwc2_hidl_->setLayerCompositionType(
+            HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
+            (Hwc2::IComposerClient::Composition)HWC2_COMPOSITION_DEVICE);
+      }
+
+      DebugHudData::data.AddLayerFrame(surface_index_);
+      acquired_buffer_.Release(std::move(release_fence_));
+      acquired_buffer_ = surface_->AcquireCurrentBuffer();
+
+      // Basic latency stopgap for when the application misses a frame:
+      // If the application recovers on the 2nd or 3rd (etc) frame after
+      // missing, this code will skip a frame to catch up by checking if
+      // the next frame is also available.
+      if (surface_->IsBufferAvailable()) {
+        DebugHudData::data.SkipLayerFrame(surface_index_);
+        ATRACE_NAME("DropToCatchUp");
+        ATRACE_ASYNC_END("BufferPost", acquired_buffer_.buffer()->id());
+        acquired_buffer_ = surface_->AcquireCurrentBuffer();
+      }
+      ATRACE_ASYNC_END("BufferPost", acquired_buffer_.buffer()->id());
+    } else if (acquired_buffer_.IsEmpty()) {
+      // While we are waiting for a buffer, set this to be an empty layer
+      if (composition_type_ != HWC2_COMPOSITION_SOLID_COLOR) {
+        composition_type_ = HWC2_COMPOSITION_SOLID_COLOR;
+        hwc2_hidl_->setLayerCompositionType(
+            HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
+            (Hwc2::IComposerClient::Composition)HWC2_COMPOSITION_SOLID_COLOR);
+
+        Hwc2::IComposerClient::Color layer_color = {
+            0, 0, 0, 0,
+        };
+        hwc2_hidl_->setLayerColor(HWC_DISPLAY_PRIMARY, hardware_composer_layer_,
+                                  layer_color);
+      }
+      return;
+    }
+    right = acquired_buffer_.buffer()->width();
+    bottom = acquired_buffer_.buffer()->height();
+    handle = acquired_buffer_.buffer()->native_handle();
+    acquire_fence_fd_.Reset(acquired_buffer_.ClaimAcquireFence().Release());
+  } else {
+    right = direct_buffer_->width();
+    bottom = direct_buffer_->height();
+    handle = direct_buffer_->handle();
+    acquire_fence_fd_.Close();
+  }
+
+  int32_t ret = HWC2_ERROR_NONE;
+
+  if (composition_type_ == HWC2_COMPOSITION_DEVICE) {
+    ret = (int32_t)hwc2_hidl_->setLayerBuffer(HWC_DISPLAY_PRIMARY,
+                                              hardware_composer_layer_, handle,
+                                              acquire_fence_fd_.Get());
+
+    ALOGE_IF(ret, "HardwareComposer: Error setting layer buffer : %d", ret);
+  }
+
+  if (!surface_rect_functions_applied_) {
+    Hwc2::IComposerClient::FRect crop_rect = {
+        0, 0, static_cast<float>(right), static_cast<float>(bottom),
+    };
+    hwc2_hidl_->setLayerSourceCrop(HWC_DISPLAY_PRIMARY,
+                                   hardware_composer_layer_, crop_rect);
+
+    ALOGE_IF(ret, "HardwareComposer: Error setting layer source crop : %d",
+             ret);
+
+// TODO(skiazyk): why is this ifdef'd out. Is if a driver-specific issue where
+// it must/cannot be called?
+#ifdef QCOM_BSP
+    hwc_rect_t damage_rect = {
+        0, 0, right, bottom,
+    };
+    hwc_region_t damage = {
+        1, &damage_rect,
+    };
+    // ret = hwc2_funcs_->set_layer_surface_damage(
+    //    hardware_composer_device_, HWC_DISPLAY_PRIMARY,
+    //    hardware_composer_layer_, damage);
+    // uses a std::vector as the listing
+    // hwc2_hidl_->setLayerSurfaceDamage(HWC_DISPLAY_PRIMARY,
+    // hardware_composer_layer_, vector here);
+
+    ALOGE_IF(ret, "HardwareComposer: Error settings layer surface damage : %d",
+             ret);
+#endif
+
+    surface_rect_functions_applied_ = true;
+  }
+}
+
+void Layer::Finish(int release_fence_fd) {
+  release_fence_.Reset(release_fence_fd);
+}
+
+void Layer::Drop() { acquire_fence_fd_.Close(); }
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/hardware_composer.h b/libs/vr/libvrflinger/hardware_composer.h
new file mode 100644
index 0000000..cfe8c84
--- /dev/null
+++ b/libs/vr/libvrflinger/hardware_composer.h
@@ -0,0 +1,406 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_HARDWARE_COMPOSER_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_HARDWARE_COMPOSER_H_
+
+#include <log/log.h>
+#include <hardware/gralloc.h>
+#include <hardware/hardware.h>
+#include <hardware/hwcomposer2.h>
+
+#include <private/dvr/buffer_hub_client.h>
+#include <private/dvr/sync_util.h>
+
+#include <array>
+#include <condition_variable>
+#include <memory>
+#include <mutex>
+#include <thread>
+#include <tuple>
+#include <vector>
+
+#include <pdx/file_handle.h>
+#include <private/dvr/buffer_hub_client.h>
+#include <private/dvr/frame_time_history.h>
+#include <private/dvr/sync_util.h>
+
+#include "acquired_buffer.h"
+#include "compositor.h"
+#include "display_surface.h"
+
+#include "DisplayHardware/ComposerHal.h"
+
+// Hardware composer HAL doesn't define HWC_TRANSFORM_NONE as of this writing.
+#ifndef HWC_TRANSFORM_NONE
+#define HWC_TRANSFORM_NONE static_cast<hwc_transform_t>(0)
+#endif
+
+namespace android {
+namespace dvr {
+
+// Basic display metrics for physical displays. Dimensions and densities are
+// relative to the physical display orientation, which may be different from the
+// logical display orientation exposed to applications.
+struct HWCDisplayMetrics {
+  int width;
+  int height;
+  struct {
+    int x;
+    int y;
+  } dpi;
+  int vsync_period_ns;
+};
+
+// Layer represents the connection between a hardware composer layer and the
+// source supplying buffers for the layer's contents.
+class Layer {
+ public:
+  Layer();
+
+  // Sets the hardware composer layer and display metrics that this Layer should
+  // use each Prepare cycle. This class does not own either of these pointers,
+  // which MUST remain valid for its lifetime. This method MUST be called once
+  // in the life of the instance before any other method is valid to call.
+  void Initialize(Hwc2::Composer* hwc2_hidl, HWCDisplayMetrics* metrics);
+
+  // Releases any shared pointers and fence handles held by this instance.
+  void Reset();
+
+  // Sets up the layer to use a display surface as its content source. The Layer
+  // will automatically handle ACQUIRE/RELEASE phases for the surface's buffer
+  // train every frame.
+  //
+  // |blending| receives HWC_BLENDING_* values.
+  // |transform| receives HWC_TRANSFORM_* values.
+  // |composition_type| receives either HWC_FRAMEBUFFER for most layers or
+  // HWC_FRAMEBUFFER_TARGET (unless you know what you are doing).
+  // |index| is the index of this surface in the DisplaySurface array.
+  void Setup(const std::shared_ptr<DisplaySurface>& surface,
+             hwc2_blend_mode_t blending, hwc_transform_t transform,
+             hwc2_composition_t composition_type, size_t index);
+
+  // Sets up the layer to use a direct buffer as its content source. No special
+  // handling of the buffer is performed; responsibility for updating or
+  // changing the buffer each frame is on the caller.
+  //
+  // |blending| receives HWC_BLENDING_* values.
+  // |transform| receives HWC_TRANSFORM_* values.
+  // |composition_type| receives either HWC_FRAMEBUFFER for most layers or
+  // HWC_FRAMEBUFFER_TARGET (unless you know what you are doing).
+  void Setup(const std::shared_ptr<IonBuffer>& buffer,
+             hwc2_blend_mode_t blending, hwc_transform_t transform,
+             hwc2_composition_t composition_type, size_t z_order);
+
+  // Layers that use a direct IonBuffer should call this each frame to update
+  // which buffer will be used for the next PostLayers.
+  void UpdateDirectBuffer(const std::shared_ptr<IonBuffer>& buffer);
+
+  // Sets up the hardware composer layer for the next frame. When the layer is
+  // associated with a display surface, this method automatically ACQUIRES a new
+  // buffer if one is available.
+  void Prepare();
+
+  // After calling prepare, if this frame is to be dropped instead of passing
+  // along to the HWC, call Drop to close the contained fence(s).
+  void Drop();
+
+  // Performs fence bookkeeping after the frame has been posted to hardware
+  // composer.
+  void Finish(int release_fence_fd);
+
+  // Sets the blending for the layer. |blending| receives HWC_BLENDING_* values.
+  void SetBlending(hwc2_blend_mode_t blending);
+
+  // Sets the Z-order of this layer
+  void SetZOrderIndex(int surface_index);
+
+  // Gets the current IonBuffer associated with this layer. Ownership of the
+  // buffer DOES NOT pass to the caller and the pointer is not guaranteed to
+  // remain valid across calls to Layer::Setup(), Layer::Prepare(), or
+  // Layer::Reset(). YOU HAVE BEEN WARNED.
+  IonBuffer* GetBuffer();
+
+  hwc2_composition_t GetCompositionType() const { return composition_type_; }
+
+  hwc2_layer_t GetLayerHandle() const { return hardware_composer_layer_; }
+
+  bool UsesDirectBuffer() const { return direct_buffer_ != nullptr; }
+
+  bool IsLayerSetup() const {
+    return direct_buffer_ != nullptr || surface_ != nullptr;
+  }
+
+  // Applies all of the settings to this layer using the hwc functions
+  void UpdateLayerSettings();
+
+  int GetSurfaceId() const {
+    if (surface_ != nullptr) {
+      return surface_->surface_id();
+    } else {
+      return -1;
+    }
+  }
+
+ private:
+  void CommonLayerSetup();
+
+  Hwc2::Composer* hwc2_hidl_;
+
+  // Original display surface array index for tracking purposes.
+  size_t surface_index_;
+
+  // The hardware composer layer and metrics to use during the prepare cycle.
+  hwc2_layer_t hardware_composer_layer_;
+  HWCDisplayMetrics* display_metrics_;
+
+  // Layer properties used to setup the hardware composer layer during the
+  // Prepare phase.
+  hwc2_blend_mode_t blending_;
+  hwc_transform_t transform_;
+  hwc2_composition_t composition_type_;
+
+  // These two members are mutually exclusive. When direct_buffer_ is set the
+  // Layer gets its contents directly from that buffer; when surface_ is set the
+  // Layer gets it contents from the surface's buffer train.
+  std::shared_ptr<IonBuffer> direct_buffer_;
+  std::shared_ptr<DisplaySurface> surface_;
+
+  // State when associated with a display surface.
+  AcquiredBuffer acquired_buffer_;
+  pdx::LocalHandle release_fence_;
+
+  pdx::LocalHandle acquire_fence_fd_;
+  bool surface_rect_functions_applied_;
+
+  Layer(const Layer&) = delete;
+  void operator=(const Layer&) = delete;
+};
+
+// HardwareComposer encapsulates the hardware composer HAL, exposing a
+// simplified API to post buffers to the display.
+class HardwareComposer {
+ public:
+  // Type for vsync callback.
+  using VSyncCallback = std::function<void(int, int64_t, int64_t, uint32_t)>;
+
+  // Since there is no universal way to query the number of hardware layers,
+  // just set it to 4 for now.
+  static constexpr int kMaxHardwareLayers = 4;
+
+  HardwareComposer();
+  HardwareComposer(Hwc2::Composer* hidl);
+  ~HardwareComposer();
+
+  bool Suspend();
+  bool Resume();
+  bool IsSuspended() const { return pause_post_thread_; }
+
+  // Get the HMD display metrics for the current display.
+  DisplayMetrics GetHmdDisplayMetrics() const;
+
+  int32_t GetDisplayAttribute(hwc2_display_t display, hwc2_config_t config,
+                              hwc2_attribute_t attributes,
+                              int32_t* out_value) const;
+  int32_t GetDisplayMetrics(hwc2_display_t display, hwc2_config_t config,
+                            HWCDisplayMetrics* out_metrics) const;
+  void Dump(char* buffer, uint32_t* out_size);
+
+  void SetVSyncCallback(VSyncCallback callback);
+
+  // Metrics of the logical display, which is always landscape.
+  int DisplayWidth() const { return display_metrics_.width; }
+  int DisplayHeight() const { return display_metrics_.height; }
+  HWCDisplayMetrics display_metrics() const { return display_metrics_; }
+
+  // Metrics of the native display, which depends on the specific hardware
+  // implementation of the display.
+  HWCDisplayMetrics native_display_metrics() const {
+    return native_display_metrics_;
+  }
+
+  std::shared_ptr<IonBuffer> framebuffer_target() const {
+    return framebuffer_target_;
+  }
+
+  // Set the display surface stack to compose to the display each frame.
+  int SetDisplaySurfaces(std::vector<std::shared_ptr<DisplaySurface>> surfaces);
+
+  Compositor* GetCompositor() { return &compositor_; }
+
+ private:
+  int32_t EnableVsync(bool enabled);
+  int32_t SetPowerMode(hwc2_display_t display, hwc2_power_mode_t mode);
+
+  class ComposerCallback : public Hwc2::IComposerCallback {
+   public:
+    ComposerCallback() {}
+
+    hardware::Return<void> onHotplug(Hwc2::Display /*display*/,
+                                     Connection /*connected*/) override {
+      // TODO(skiazyk): depending on how the server is implemented, we might
+      // have to set it up to synchronize with receiving this event, as it can
+      // potentially be a critical event for setting up state within the
+      // hwc2 module. That is, we (technically) should not call any other hwc
+      // methods until this method has been called after registering the
+      // callbacks.
+      return hardware::Void();
+    }
+
+    hardware::Return<void> onRefresh(Hwc2::Display /*display*/) override {
+      return hardware::Void();
+    }
+
+    hardware::Return<void> onVsync(Hwc2::Display /*display*/,
+                                   int64_t /*timestamp*/) override {
+      return hardware::Void();
+    }
+  };
+
+  int32_t Validate(hwc2_display_t display);
+  int32_t Present(hwc2_display_t display);
+
+  void SetBacklightBrightness(int brightness);
+
+  void PostLayers(bool is_geometry_changed);
+  void PostThread();
+
+  int ReadWaitPPState();
+  int BlockUntilVSync();
+  int ReadVSyncTimestamp(int64_t* timestamp);
+  int WaitForVSync(int64_t* timestamp);
+  int SleepUntil(int64_t wakeup_timestamp);
+
+  bool IsFramePendingInDriver() { return ReadWaitPPState() == 1; }
+
+  // Returns true if the layer config changed, false otherwise
+  bool UpdateLayerConfig(
+      std::vector<std::shared_ptr<DisplaySurface>>* compositor_surfaces);
+  void PostCompositorBuffers(
+      const std::vector<std::shared_ptr<DisplaySurface>>& compositor_surfaces);
+
+  void UpdateDisplayState();
+
+  struct FrameTimeMeasurementRecord {
+    int64_t start_time;
+    pdx::LocalHandle fence;
+
+    FrameTimeMeasurementRecord(FrameTimeMeasurementRecord&&) = default;
+    FrameTimeMeasurementRecord& operator=(FrameTimeMeasurementRecord&&) =
+        default;
+    FrameTimeMeasurementRecord(const FrameTimeMeasurementRecord&) = delete;
+    FrameTimeMeasurementRecord& operator=(const FrameTimeMeasurementRecord&) =
+        delete;
+  };
+
+  void UpdateFrameTimeHistory(std::vector<FrameTimeMeasurementRecord>* backlog,
+                              int backlog_max,
+                              FenceInfoBuffer* fence_info_buffer,
+                              FrameTimeHistory* history);
+
+  // Returns true if the frame finished rendering, false otherwise. If the frame
+  // finished the frame end time is stored in timestamp. Doesn't block.
+  bool CheckFrameFinished(int frame_fence_fd,
+                          FenceInfoBuffer* fence_info_buffer,
+                          int64_t* timestamp);
+
+  void HandlePendingScreenshots();
+
+  void PausePostThread();
+
+  // Hardware composer HAL device.
+  std::unique_ptr<Hwc2::Composer> hwc2_hidl_;
+  sp<ComposerCallback> callbacks_;
+
+  // Display metrics of the physical display.
+  HWCDisplayMetrics native_display_metrics_;
+  // Display metrics of the logical display, adjusted so that orientation is
+  // landscape.
+  HWCDisplayMetrics display_metrics_;
+  // Transform required to get from native to logical display orientation.
+  hwc_transform_t display_transform_;
+
+  // Buffer for the background layer required by hardware composer.
+  std::shared_ptr<IonBuffer> framebuffer_target_;
+
+  // Protects access to the display surfaces and logical layers.
+  std::mutex layer_mutex_;
+
+  // Active display surfaces configured by the display manager.
+  std::vector<std::shared_ptr<DisplaySurface>> display_surfaces_;
+  std::vector<std::shared_ptr<DisplaySurface>> added_display_surfaces_;
+  bool display_surfaces_updated_;
+  bool hardware_layers_need_update_;
+
+  // Cache whether the display was turned on by us
+  bool display_on_; // TODO(hendrikw): The display is always on. Revisit.
+
+  // Layer array for handling buffer flow into hardware composer layers.
+  // Note that the first array is the actual storage for the layer objects,
+  // and the latter is an array of pointers, which can be freely re-arranged
+  // without messing up the underlying objects.
+  std::array<Layer, kMaxHardwareLayers> layer_storage_;
+  std::array<Layer*, kMaxHardwareLayers> layers_;
+  size_t active_layer_count_;
+
+  // Set by the Post thread to the index of the GPU compositing output
+  // buffer in the layers_ array.
+  Layer* gpu_layer_;
+
+  // Handler to hook vsync events outside of this class.
+  VSyncCallback vsync_callback_;
+
+  // Thread and condition for managing the layer posting thread. This thread
+  // wakes up a short time before vsync to hand buffers to post processing and
+  // the results to hardware composer.
+  std::thread post_thread_;
+
+  // Control variables to control the state of the post thread
+  pdx::LocalHandle terminate_post_thread_event_fd_;
+  bool pause_post_thread_;
+  std::mutex thread_pause_mutex_;
+  std::condition_variable thread_pause_semaphore_;
+
+  // Backlight LED brightness sysfs node.
+  pdx::LocalHandle backlight_brightness_fd_;
+
+  // Primary display vsync event sysfs node.
+  pdx::LocalHandle primary_display_vsync_event_fd_;
+
+  // Primary display wait_pingpong state sysfs node.
+  pdx::LocalHandle primary_display_wait_pp_fd_;
+
+  // VSync sleep timerfd.
+  pdx::LocalHandle vsync_sleep_timer_fd_;
+
+  // The timestamp of the last vsync.
+  int64_t last_vsync_timestamp_;
+
+  // Vsync count since display on.
+  uint32_t vsync_count_;
+
+  // Counter tracking the number of skipped frames.
+  int frame_skip_count_;
+
+  // After construction, only accessed on post_thread_.
+  Compositor compositor_;
+
+  // Fd array for tracking retire fences that are returned by hwc. This allows
+  // us to detect when the display driver begins queuing frames.
+  std::vector<pdx::LocalHandle> retire_fence_fds_;
+
+  // Pose client for frame count notifications. Pose client predicts poses
+  // out to display frame boundaries, so we need to tell it about vsyncs.
+  DvrPose* pose_client_;
+
+  static void HwcRefresh(hwc2_callback_data_t data, hwc2_display_t display);
+  static void HwcVSync(hwc2_callback_data_t data, hwc2_display_t display,
+                       int64_t timestamp);
+  static void HwcHotplug(hwc2_callback_data_t callbackData,
+                         hwc2_display_t display, hwc2_connection_t connected);
+
+  HardwareComposer(const HardwareComposer&) = delete;
+  void operator=(const HardwareComposer&) = delete;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_HARDWARE_COMPOSER_H_
diff --git a/libs/vr/libvrflinger/include/dvr/vr_flinger.h b/libs/vr/libvrflinger/include/dvr/vr_flinger.h
new file mode 100644
index 0000000..04c8363
--- /dev/null
+++ b/libs/vr/libvrflinger/include/dvr/vr_flinger.h
@@ -0,0 +1,33 @@
+#ifndef ANDROID_DVR_VR_FLINGER_H_
+#define ANDROID_DVR_VR_FLINGER_H_
+
+#include <thread>
+#include <memory>
+
+namespace android {
+
+namespace Hwc2 {
+class Composer;
+}  // namespace Hwc2
+
+namespace dvr {
+
+class DisplayService;
+
+class VrFlinger {
+ public:
+  VrFlinger();
+  int Run(Hwc2::Composer* hidl);
+
+  void EnterVrMode();
+  void ExitVrMode();
+
+ private:
+  std::thread displayd_thread_;
+  std::shared_ptr<android::dvr::DisplayService> display_service_;
+};
+
+} // namespace dvr
+} // namespace android
+
+#endif // ANDROID_DVR_VR_FLINGER_H_
diff --git a/libs/vr/libvrflinger/screenshot_service.cpp b/libs/vr/libvrflinger/screenshot_service.cpp
new file mode 100644
index 0000000..e174943
--- /dev/null
+++ b/libs/vr/libvrflinger/screenshot_service.cpp
@@ -0,0 +1,181 @@
+#include "screenshot_service.h"
+
+#include <utils/Trace.h>
+
+#include <pdx/default_transport/service_endpoint.h>
+#include <private/dvr/display_types.h>
+
+using android::pdx::Message;
+using android::pdx::MessageInfo;
+using android::pdx::default_transport::Endpoint;
+using android::pdx::rpc::DispatchRemoteMethod;
+using android::pdx::rpc::RemoteMethodError;
+using android::pdx::rpc::RemoteMethodReturn;
+
+namespace android {
+namespace dvr {
+
+ScreenshotService::~ScreenshotService() { instance_ = nullptr; }
+
+int ScreenshotService::HandleMessage(pdx::Message& message) {
+  switch (message.GetOp()) {
+    case DisplayScreenshotRPC::GetFormat::Opcode:
+      DispatchRemoteMethod<DisplayScreenshotRPC::GetFormat>(
+          *this, &ScreenshotService::OnGetFormat, message);
+      return 0;
+
+    case DisplayScreenshotRPC::TakeScreenshot::Opcode:
+      DispatchRemoteMethod<DisplayScreenshotRPC::TakeScreenshot>(
+          *this, &ScreenshotService::OnTakeScreenshot, message);
+      return 0;
+
+    default:
+      return Service::HandleMessage(message);
+  }
+}
+
+int ScreenshotService::OnGetFormat(pdx::Message&) {
+  return HAL_PIXEL_FORMAT_RGB_888;
+}
+
+ScreenshotData ScreenshotService::OnTakeScreenshot(pdx::Message& message,
+                                                   int layer_index) {
+  AddWaiter(std::move(message), layer_index);
+  return {};
+}
+
+void ScreenshotService::AddWaiter(pdx::Message&& message, int layer_index) {
+  std::lock_guard<std::mutex> lock(mutex_);
+  waiters_.emplace_back(std::move(message), layer_index);
+}
+
+void ScreenshotService::TakeIfNeeded(
+    std::array<Layer*, HardwareComposer::kMaxHardwareLayers>& hw_layers,
+    Compositor& compositor) {
+  std::lock_guard<std::mutex> lock(mutex_);
+
+  // Send the buffer contents to all of our waiting clients.
+  for (auto& waiter : waiters_) {
+    if (waiter.IsDone())
+      continue;
+
+    if (waiter.layer_index() == 0) {
+      ALOGE(
+          "ScreenshotService::TakeIfNeeded: Capturing the composited display "
+          "output is not yet supported.");
+
+      waiter.Error(EINVAL);
+      continue;
+    }
+
+    if (waiter.layer_index() > 0) {
+      // Check for hardware layer screenshot requests.
+      // Hardware layers are requested with positive indices starting at 1.
+      const size_t layer_index = static_cast<size_t>(waiter.layer_index() - 1);
+
+      if (layer_index >= hw_layers.size()) {
+        waiter.Error(EINVAL);
+        continue;
+      }
+
+      auto buffer = hw_layers[layer_index]->GetBuffer();
+      if (!buffer) {
+        waiter.Error(ENOBUFS);
+        continue;
+      }
+
+      auto data = compositor.ReadBufferPixels(buffer);
+      if (data.empty()) {
+        waiter.Error(ENOBUFS);
+        continue;
+      }
+
+      Take(&waiter, data.data(), buffer->width(), buffer->height(),
+           buffer->width());
+    } else {
+      // Check for compositor input layer screenshot requests.
+      // Prewarp surfaces are requested with negative indices starting at -1.
+      const size_t layer_index = static_cast<size_t>(-waiter.layer_index() - 1);
+
+      if (layer_index >= compositor.GetLayerCount()) {
+        waiter.Error(EINVAL);
+        continue;
+      }
+
+      int width = 0;
+      int height = 0;
+      auto data = compositor.ReadLayerPixels(layer_index, &width, &height);
+      if (data.empty()) {
+        waiter.Error(ENOBUFS);
+        continue;
+      }
+
+      Take(&waiter, data.data(), width, height, width);
+    }
+  }
+
+  // Reply with error to requests that did not match up with a source layer.
+  for (auto& waiter : waiters_) {
+    if (!waiter.IsDone())
+      waiter.Error(EAGAIN);
+  }
+  waiters_.clear();
+}
+
+void ScreenshotWaiter::Reply(const ScreenshotData& screenshot) {
+  ALOGI("Returning screenshot: size=%zu recv_size=%zu",
+        screenshot.buffer.size(), message_.GetReceiveLength());
+  RemoteMethodReturn<DisplayScreenshotRPC::TakeScreenshot>(message_,
+                                                           screenshot);
+}
+
+void ScreenshotWaiter::Error(int error) { RemoteMethodError(message_, error); }
+
+void ScreenshotService::Take(ScreenshotWaiter* waiter, const void* rgba_data,
+                             int32_t width, int32_t height, int buffer_stride) {
+  ATRACE_NAME(__PRETTY_FUNCTION__);
+
+  bool is_portrait = height > width;
+  if (is_portrait) {
+    std::swap(width, height);
+  }
+  int response_stride = width;
+
+  // Convert from RGBA to RGB and if in portrait, rotates to landscape; store
+  // the result in the response buffer.
+  ScreenshotData screenshot{width, height,
+                            std::vector<uint8_t>(width * height * 3)};
+
+  const auto rgba_bytes = static_cast<const uint8_t*>(rgba_data);
+  for (int j = 0; j < height; ++j) {
+    for (int i = 0; i < width; ++i) {
+      // If the screenshot is in portrait mode, rotate into landscape mode.
+      const int response_index = is_portrait
+                                     ? (height - j - 1) * response_stride + i
+                                     : j * response_stride + i;
+      const int buffer_index =
+          is_portrait ? i * buffer_stride + j : j * buffer_stride + i;
+      screenshot.buffer[response_index * 3 + 0] =
+          rgba_bytes[buffer_index * 4 + 0];
+      screenshot.buffer[response_index * 3 + 1] =
+          rgba_bytes[buffer_index * 4 + 1];
+      screenshot.buffer[response_index * 3 + 2] =
+          rgba_bytes[buffer_index * 4 + 2];
+    }
+  }
+
+  waiter->Reply(screenshot);
+}
+
+ScreenshotService::ScreenshotService()
+    : BASE("ScreenshotService",
+           Endpoint::Create(DisplayScreenshotRPC::kClientPath)) {
+  instance_ = this;
+}
+
+ScreenshotService* ScreenshotService::GetInstance() { return instance_; }
+
+ScreenshotService* ScreenshotService::instance_ = nullptr;
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/screenshot_service.h b/libs/vr/libvrflinger/screenshot_service.h
new file mode 100644
index 0000000..ec4c527
--- /dev/null
+++ b/libs/vr/libvrflinger/screenshot_service.h
@@ -0,0 +1,82 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_SCREENSHOT_SERVICE_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_SCREENSHOT_SERVICE_H_
+
+#include <pdx/rpc/pointer_wrapper.h>
+#include <pdx/service.h>
+#include <private/dvr/ion_buffer.h>
+
+#include <mutex>
+#include <vector>
+
+#include "hardware_composer.h"
+
+namespace android {
+namespace dvr {
+
+class ScreenshotWaiter {
+ public:
+  explicit ScreenshotWaiter(pdx::Message&& message, int layer_index)
+      : message_(std::move(message)), layer_index_(layer_index) {}
+  ScreenshotWaiter(ScreenshotWaiter&&) = default;
+
+  void Reply(const ScreenshotData& screenshot);
+  void Error(int error);
+
+  bool IsDone() const { return message_.replied(); }
+  int layer_index() const { return layer_index_; }
+
+ private:
+  pdx::Message message_;
+  int layer_index_;
+
+  ScreenshotWaiter(const ScreenshotWaiter&) = delete;
+  void operator=(const ScreenshotWaiter&) = delete;
+};
+
+// The screenshot service allows clients to obtain screenshots from displayd.
+class ScreenshotService : public pdx::ServiceBase<ScreenshotService> {
+ public:
+  ~ScreenshotService();
+
+  int HandleMessage(pdx::Message& message) override;
+
+  // Returns true if there is a pending screenshot request.
+  bool IsScreenshotRequestPending() const {
+    std::lock_guard<std::mutex> lock(mutex_);
+    return !waiters_.empty();
+  }
+
+  // If any clients are currently waiting for a screenshot, read back the
+  // contents of requested layers and send the resulting
+  // image to the clients.
+  void TakeIfNeeded(
+      std::array<Layer*, HardwareComposer::kMaxHardwareLayers>& hw_layers,
+      Compositor& compositor);
+
+  static ScreenshotService* GetInstance();
+
+ private:
+  friend BASE;
+
+  ScreenshotService();
+
+  void AddWaiter(pdx::Message&& message, int layer_index);
+
+  ScreenshotData OnTakeScreenshot(pdx::Message& message, int index);
+  int OnGetFormat(pdx::Message& message);
+
+  // Copy the given screenshot data into the message reply.
+  void Take(ScreenshotWaiter* waiter, const void* rgba_data, int32_t width,
+            int32_t height, int buffer_stride);
+
+  static ScreenshotService* instance_;
+
+  // Protects access to subsequent member variables.
+  mutable std::mutex mutex_;
+  std::vector<ScreenshotWaiter> waiters_;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_SCREENSHOT_SERVICE_H_
diff --git a/libs/vr/libvrflinger/surface_channel.cpp b/libs/vr/libvrflinger/surface_channel.cpp
new file mode 100644
index 0000000..8aa220b
--- /dev/null
+++ b/libs/vr/libvrflinger/surface_channel.cpp
@@ -0,0 +1,44 @@
+#include "surface_channel.h"
+
+using android::pdx::BorrowedChannelHandle;
+using android::pdx::Message;
+using android::pdx::rpc::DispatchRemoteMethod;
+
+namespace android {
+namespace dvr {
+
+int SurfaceChannel::HandleMessage(Message& message) {
+  switch (message.GetOp()) {
+    case DisplayRPC::GetMetadataBuffer::Opcode:
+      DispatchRemoteMethod<DisplayRPC::GetMetadataBuffer>(
+          *this, &SurfaceChannel::OnGetMetadataBuffer, message);
+      break;
+  }
+
+  return 0;
+}
+
+BorrowedChannelHandle SurfaceChannel::OnGetMetadataBuffer(Message& message) {
+  if (EnsureMetadataBuffer()) {
+    return metadata_buffer_->GetChannelHandle().Borrow();
+  } else {
+    REPLY_ERROR_RETURN(message, -ENOMEM, {});
+  }
+}
+
+bool SurfaceChannel::EnsureMetadataBuffer() {
+  if (!metadata_buffer_) {
+    metadata_buffer_ =
+        BufferProducer::CreateUncachedBlob(metadata_size());
+    if (!metadata_buffer_) {
+      ALOGE(
+          "DisplaySurface::EnsureMetadataBuffer: could not allocate metadata "
+          "buffer");
+      return false;
+    }
+  }
+  return true;
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/surface_channel.h b/libs/vr/libvrflinger/surface_channel.h
new file mode 100644
index 0000000..870e1a4
--- /dev/null
+++ b/libs/vr/libvrflinger/surface_channel.h
@@ -0,0 +1,63 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_SURFACE_CHANNEL_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_SURFACE_CHANNEL_H_
+
+#include <pdx/service.h>
+#include <private/dvr/buffer_hub_client.h>
+#include <private/dvr/display_rpc.h>
+
+namespace android {
+namespace dvr {
+
+class DisplayService;
+
+class SurfaceChannel : public pdx::Channel {
+ public:
+  SurfaceChannel(DisplayService* service, int channel_id, SurfaceType type,
+                 size_t metadata_size)
+      : service_(service),
+        surface_id_(channel_id),
+        type_(type),
+        metadata_size_(metadata_size) {}
+
+  ~SurfaceChannel() override = default;
+
+  DisplayService* service() const { return service_; }
+  int surface_id() const { return surface_id_; }
+  SurfaceType type() const { return type_; }
+  size_t metadata_size() const { return metadata_size_; }
+
+  pdx::LocalHandle GetMetadataBufferFd() {
+    return EnsureMetadataBuffer() ? metadata_buffer_->GetBlobFd()
+                                  : pdx::LocalHandle{};
+  }
+
+  // Dispatches surface channel messages to the appropriate handlers. This
+  // handler runs on the displayd message dispatch thread.
+  virtual int HandleMessage(pdx::Message& message);
+
+ protected:
+  // Contains the surface metadata.
+  std::shared_ptr<BufferProducer> metadata_buffer_;
+
+  // Returns the metadata buffer for this surface. The first call allocates the
+  // buffer, while subsequent calls return the same buffer.
+  pdx::BorrowedChannelHandle OnGetMetadataBuffer(pdx::Message& message);
+
+  // Allocates the single metadata buffer for this surface unless it is already
+  // allocated. Idempotent when called multiple times.
+  bool EnsureMetadataBuffer();
+
+ private:
+  DisplayService* service_;
+  int surface_id_;
+  SurfaceType type_;
+  size_t metadata_size_;
+
+  SurfaceChannel(const SurfaceChannel&) = delete;
+  void operator=(const SurfaceChannel&) = delete;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_SURFACE_CHANNEL_H_
diff --git a/libs/vr/libvrflinger/video_compositor.cpp b/libs/vr/libvrflinger/video_compositor.cpp
new file mode 100644
index 0000000..6b39a3c
--- /dev/null
+++ b/libs/vr/libvrflinger/video_compositor.cpp
@@ -0,0 +1,129 @@
+#include "video_compositor.h"
+
+#include <EGL/eglext.h>
+#include <GLES2/gl2ext.h>
+
+#include <private/dvr/debug.h>
+#include <private/dvr/display_rpc.h>
+
+namespace android {
+namespace dvr {
+
+VideoCompositor::Texture::Texture(
+    EGLDisplay display, const std::shared_ptr<BufferConsumer>& buffer_consumer)
+    : display_(display),
+      image_(EGL_NO_IMAGE_KHR),
+      texture_id_(0),
+      buffer_consumer_(buffer_consumer) {}
+
+VideoCompositor::Texture::~Texture() {
+  if (image_ != EGL_NO_IMAGE_KHR)
+    eglDestroyImageKHR(display_, image_);
+  if (texture_id_ != 0)
+    glDeleteTextures(1, &texture_id_);
+}
+
+GLuint VideoCompositor::Texture::EnsureTextureReady() {
+  if (!image_) {
+    native_buffer_ = new NativeBuffer(buffer_consumer_);
+    CHECK_GL();
+
+    image_ = eglCreateImageKHR(
+        display_, EGL_NO_CONTEXT, EGL_NATIVE_BUFFER_ANDROID,
+        static_cast<ANativeWindowBuffer*>(native_buffer_.get()), nullptr);
+    if (!image_) {
+      ALOGE("Failed to create EGLImage.");
+      return 0;
+    }
+
+    glGenTextures(1, &texture_id_);
+    glBindTexture(GL_TEXTURE_EXTERNAL_OES, texture_id_);
+    glEGLImageTargetTexture2DOES(GL_TEXTURE_EXTERNAL_OES, image_);
+    glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_WRAP_S,
+                    GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_WRAP_T,
+                    GL_CLAMP_TO_EDGE);
+    CHECK_GL();
+  }
+
+  return texture_id_;
+}
+
+void VideoCompositor::Texture::Release() {
+  const int ret = buffer_consumer_->Release({});
+  if (ret < 0) {
+    ALOGE(
+        "VideoCompositor::Texture::Release: Failed to release buffer, error: "
+        "%s",
+        strerror(-ret));
+  }
+}
+
+VideoCompositor::VideoCompositor(
+    const std::shared_ptr<VideoMeshSurface>& surface,
+    const volatile DisplaySurfaceMetadata* display_surface_metadata)
+    : surface_(surface),
+      consumer_queue_(surface->GetConsumerQueue()),
+      transform_metadata_(display_surface_metadata),
+      active_texture_slot_(-1) {}
+
+GLuint VideoCompositor::GetActiveTextureId(EGLDisplay display) {
+  size_t slot;
+  VideoMeshSurfaceBufferMetadata metadata;
+
+  while (true) {
+    // A native way to pick the active texture: always dequeue all buffers from
+    // the queue until it's empty. This works well as long as video frames are
+    // queued in order from the producer side.
+    // TODO(jwcai) Use |metadata.timestamp_ns| to schedule video frames
+    // accurately.
+    auto buffer_consumer = consumer_queue_->Dequeue(0, &slot, &metadata);
+
+    if (buffer_consumer) {
+      // Create a new texture if it hasn't been created yet, or the same slot
+      // has a new |buffer_consumer|.
+      if (textures_[slot] == nullptr ||
+          textures_[slot]->event_fd() != buffer_consumer->event_fd()) {
+        textures_[slot] =
+            std::unique_ptr<Texture>(new Texture(display, buffer_consumer));
+      }
+
+      if (active_texture_slot_ != static_cast<int>(slot)) {
+        if (active_texture_slot_ >= 0) {
+          // Release the last active texture and move on to use the new one.
+          textures_[active_texture_slot_]->Release();
+        }
+        active_texture_slot_ = slot;
+      }
+    } else {
+      break;
+    }
+  }
+
+  if (active_texture_slot_ < 0) {
+    // No texture is active yet.
+    return 0;
+  }
+
+  return textures_[active_texture_slot_]->EnsureTextureReady();
+}
+
+mat4 VideoCompositor::GetTransform(int eye, size_t render_buffer_index) {
+  volatile const VideoMeshSurfaceMetadata* transform_metadata =
+      surface_->GetMetadataBufferPtr();
+
+  mat4 screen_transform;
+  for (int i = 0; i < 4; ++i) {
+    for (int j = 0; j < 4; ++j) {
+      screen_transform(i, j) =
+          transform_metadata->transform[render_buffer_index][eye].val[i][j];
+    }
+  }
+
+  return screen_transform;
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/video_compositor.h b/libs/vr/libvrflinger/video_compositor.h
new file mode 100644
index 0000000..d0e72e1
--- /dev/null
+++ b/libs/vr/libvrflinger/video_compositor.h
@@ -0,0 +1,84 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_VIDEO_COMPOSITOR_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_VIDEO_COMPOSITOR_H_
+
+#include <EGL/egl.h>
+#include <GLES2/gl2.h>
+#include <private/dvr/buffer_hub_queue_core.h>
+#include <private/dvr/types.h>
+
+#include <vector>
+
+#include "display_surface.h"
+#include "video_mesh_surface.h"
+
+namespace android {
+namespace dvr {
+
+using pdx::LocalHandle;
+
+// Manages video buffer consumers, texture mapping, and playback timing.
+class VideoCompositor {
+ public:
+  VideoCompositor(
+      const std::shared_ptr<VideoMeshSurface>& surface,
+      const volatile DisplaySurfaceMetadata* display_surface_metadata);
+
+  int surface_id() const { return surface_ ? surface_->surface_id() : -1; }
+
+  // Returns a GL texture id that should be composited by displayd during the
+  // current rendering loop. Note that this function must be called in
+  // displayd's GL context.
+  GLuint GetActiveTextureId(EGLDisplay display);
+
+  // Returns a basic video mesh tranform.
+  mat4 GetTransform(int eye, size_t render_buffer_index);
+
+ private:
+  class Texture {
+   public:
+    Texture(EGLDisplay display,
+            const std::shared_ptr<BufferConsumer>& buffer_consumer);
+    ~Texture();
+
+    // Returns the |event_fd| of the underlying buffer consumer. Caller can use
+    // this to decided whether the Texture need to be recreated for a different
+    // buffer consumer.
+    int event_fd() const { return buffer_consumer_->event_fd(); }
+
+    // Method to map a dvr::BufferConsumer to a GL texture within the current GL
+    // context. If the current Texture object's |image_| hasn't been
+    // initialized, the method will do so based on the |buffer_consumer| and a
+    // new GL texture will be generated, cached, and returned. Otherwise, the
+    // cached |texture_id_| will be returned directly.
+    GLuint EnsureTextureReady();
+
+    // Signal bufferhub that the texture is done rendering so that the buffer
+    // can be re-gained by the producer for future use.
+    void Release();
+
+   private:
+    using NativeBuffer = BufferHubQueueCore::NativeBuffer;
+
+    EGLDisplay display_;
+    EGLImageKHR image_;
+    GLuint texture_id_;
+    sp<NativeBuffer> native_buffer_;
+    std::shared_ptr<BufferConsumer> buffer_consumer_;
+  };
+
+  std::shared_ptr<VideoMeshSurface> surface_;
+  std::shared_ptr<ConsumerQueue> consumer_queue_;
+  std::array<std::unique_ptr<Texture>, BufferHubQueue::kMaxQueueCapacity>
+      textures_;
+
+  const volatile DisplaySurfaceMetadata* transform_metadata_;
+  int active_texture_slot_;
+
+  VideoCompositor(const VideoCompositor&) = delete;
+  void operator=(const VideoCompositor&) = delete;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_VIDEO_COMPOSITOR_H_
diff --git a/libs/vr/libvrflinger/video_mesh_surface.cpp b/libs/vr/libvrflinger/video_mesh_surface.cpp
new file mode 100644
index 0000000..a961a3d
--- /dev/null
+++ b/libs/vr/libvrflinger/video_mesh_surface.cpp
@@ -0,0 +1,59 @@
+#include "video_mesh_surface.h"
+
+#include <private/dvr/display_rpc.h>
+
+using android::pdx::LocalChannelHandle;
+using android::pdx::rpc::DispatchRemoteMethod;
+
+namespace android {
+namespace dvr {
+
+VideoMeshSurface::VideoMeshSurface(DisplayService* service, int surface_id)
+    : SurfaceChannel(service, surface_id, SurfaceTypeEnum::VideoMesh,
+                     sizeof(VideoMeshSurfaceMetadata)) {}
+
+VideoMeshSurface::~VideoMeshSurface() {}
+
+int VideoMeshSurface::HandleMessage(Message& message) {
+  ATRACE_NAME("VideoMeshSurface::HandleMessage");
+
+  switch (message.GetOp()) {
+    case DisplayRPC::VideoMeshSurfaceCreateProducerQueue::Opcode:
+      DispatchRemoteMethod<DisplayRPC::VideoMeshSurfaceCreateProducerQueue>(
+          *this, &VideoMeshSurface::OnCreateProducerQueue, message);
+      break;
+
+    default:
+      return SurfaceChannel::HandleMessage(message);
+  }
+
+  return 0;
+}
+
+std::shared_ptr<ConsumerQueue> VideoMeshSurface::GetConsumerQueue() {
+  if (!consumer_queue_) {
+    ALOGE(
+        "VideoMeshSurface::GetConsumerQueue: consumer_queue is uninitialized.");
+  }
+
+  return consumer_queue_;
+}
+
+LocalChannelHandle VideoMeshSurface::OnCreateProducerQueue(Message& message) {
+  ATRACE_NAME("VideoMeshSurface::OnCreateProducerQueue");
+
+  if (consumer_queue_ != nullptr) {
+    ALOGE(
+        "VideoMeshSurface::OnCreateProducerQueue: A ProdcuerQueue has already "
+        "been created and transported to VideoMeshSurfaceClient.");
+    REPLY_ERROR_RETURN(message, EALREADY, {});
+  }
+
+  auto producer = ProducerQueue::Create<VideoMeshSurfaceBufferMetadata>();
+  consumer_queue_ = producer->CreateConsumerQueue();
+
+  return std::move(producer->GetChannelHandle());
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/video_mesh_surface.h b/libs/vr/libvrflinger/video_mesh_surface.h
new file mode 100644
index 0000000..1370793
--- /dev/null
+++ b/libs/vr/libvrflinger/video_mesh_surface.h
@@ -0,0 +1,52 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_VIDEO_MESH_SURFACE_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_VIDEO_MESH_SURFACE_H_
+
+#include <private/dvr/buffer_hub_queue_client.h>
+
+#include "surface_channel.h"
+
+namespace android {
+namespace dvr {
+
+class DisplayService;
+
+// VideoMeshSurface takes three inputs: 1) buffers filled by Android system
+// components (e.g. MediaCodec or camera stack) other than applications' GL
+// context; 2) a 3D mesh choosen by application to define the shape of the
+// surface; 3) a transformation matrix from application to define the rotation,
+// position, and scaling of the video surface.
+class VideoMeshSurface : public SurfaceChannel {
+ public:
+  using Message = pdx::Message;
+  using LocalChannelHandle = pdx::LocalChannelHandle;
+
+  VideoMeshSurface(DisplayService* service, int channel_id);
+  ~VideoMeshSurface() override;
+
+  volatile const VideoMeshSurfaceMetadata* GetMetadataBufferPtr() {
+    if (EnsureMetadataBuffer()) {
+      void* addr = nullptr;
+      metadata_buffer_->GetBlobReadWritePointer(metadata_size(), &addr);
+      return static_cast<const volatile VideoMeshSurfaceMetadata*>(addr);
+    } else {
+      return nullptr;
+    }
+  }
+
+  int HandleMessage(Message& message) override;
+
+  std::shared_ptr<ConsumerQueue> GetConsumerQueue();
+
+ private:
+  LocalChannelHandle OnCreateProducerQueue(Message& message);
+
+  std::shared_ptr<ConsumerQueue> consumer_queue_;
+
+  VideoMeshSurface(const VideoMeshSurface&) = delete;
+  void operator=(const VideoMeshSurface&) = delete;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_VIDEO_MESH_SURFACE_H_
diff --git a/libs/vr/libvrflinger/vr_flinger.cpp b/libs/vr/libvrflinger/vr_flinger.cpp
new file mode 100644
index 0000000..07f36a4
--- /dev/null
+++ b/libs/vr/libvrflinger/vr_flinger.cpp
@@ -0,0 +1,107 @@
+#include <dvr/vr_flinger.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <signal.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <memory>
+
+#include <binder/ProcessState.h>
+#include <log/log.h>
+#include <cutils/properties.h>
+#include <cutils/sched_policy.h>
+#include <private/dvr/display_client.h>
+#include <sys/resource.h>
+
+#include <pdx/default_transport/service_dispatcher.h>
+
+#include <functional>
+
+#include "DisplayHardware/ComposerHal.h"
+#include "display_manager_service.h"
+#include "display_service.h"
+#include "screenshot_service.h"
+#include "vsync_service.h"
+
+namespace android {
+namespace dvr {
+
+VrFlinger::VrFlinger() {}
+
+int VrFlinger::Run(Hwc2::Composer* hidl) {
+  std::shared_ptr<android::pdx::Service> service;
+
+  ALOGI("Starting up VrFlinger...");
+
+  setpriority(PRIO_PROCESS, 0, android::PRIORITY_URGENT_DISPLAY);
+  set_sched_policy(0, SP_FOREGROUND);
+
+  // We need to be able to create endpoints with full perms.
+  umask(0000);
+
+  android::ProcessState::self()->startThreadPool();
+
+  std::shared_ptr<android::pdx::ServiceDispatcher> dispatcher =
+      android::pdx::default_transport::ServiceDispatcher::Create();
+  CHECK_ERROR(!dispatcher, error, "Failed to create service dispatcher.");
+
+  display_service_ = android::dvr::DisplayService::Create(hidl);
+  CHECK_ERROR(!display_service_, error, "Failed to create display service.");
+  dispatcher->AddService(display_service_);
+
+  service = android::dvr::DisplayManagerService::Create(display_service_);
+  CHECK_ERROR(!service, error, "Failed to create display manager service.");
+  dispatcher->AddService(service);
+
+  service = android::dvr::ScreenshotService::Create();
+  CHECK_ERROR(!service, error, "Failed to create screenshot service.");
+  dispatcher->AddService(service);
+
+  service = android::dvr::VSyncService::Create();
+  CHECK_ERROR(!service, error, "Failed to create vsync service.");
+  dispatcher->AddService(service);
+
+  display_service_->SetVSyncCallback(
+      std::bind(&android::dvr::VSyncService::VSyncEvent,
+                std::static_pointer_cast<android::dvr::VSyncService>(service),
+                std::placeholders::_1, std::placeholders::_2,
+                std::placeholders::_3, std::placeholders::_4));
+
+  displayd_thread_ = std::thread([this, dispatcher]() {
+    ALOGI("Entering message loop.");
+
+    int ret = dispatcher->EnterDispatchLoop();
+    if (ret < 0) {
+      ALOGE("Dispatch loop exited because: %s\n", strerror(-ret));
+    }
+  });
+
+  return NO_ERROR;
+
+error:
+  display_service_.reset();
+
+  return -1;
+}
+
+void VrFlinger::EnterVrMode() {
+  if (display_service_) {
+    display_service_->SetActive(true);
+  } else {
+    ALOGE("Failed to enter VR mode : Display service is not started.");
+  }
+}
+
+void VrFlinger::ExitVrMode() {
+  if (display_service_) {
+    display_service_->SetActive(false);
+  } else {
+    ALOGE("Failed to exit VR mode : Display service is not started.");
+  }
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/vsync_service.cpp b/libs/vr/libvrflinger/vsync_service.cpp
new file mode 100644
index 0000000..48fa2c2
--- /dev/null
+++ b/libs/vr/libvrflinger/vsync_service.cpp
@@ -0,0 +1,208 @@
+#include "vsync_service.h"
+
+#include <log/log.h>
+#include <hardware/hwcomposer.h>
+#include <poll.h>
+#include <sys/prctl.h>
+#include <time.h>
+#include <utils/Trace.h>
+
+#include <pdx/default_transport/service_endpoint.h>
+#include <private/dvr/clock_ns.h>
+#include <private/dvr/display_rpc.h>
+#include <private/dvr/display_types.h>
+
+using android::pdx::Channel;
+using android::pdx::Message;
+using android::pdx::MessageInfo;
+using android::pdx::default_transport::Endpoint;
+using android::pdx::rpc::DispatchRemoteMethod;
+
+namespace android {
+namespace dvr {
+
+VSyncService::VSyncService()
+    : BASE("VSyncService", Endpoint::Create(DisplayVSyncRPC::kClientPath)),
+      last_vsync_(0),
+      current_vsync_(0),
+      compositor_time_ns_(0),
+      current_vsync_count_(0) {}
+
+VSyncService::~VSyncService() {}
+
+void VSyncService::VSyncEvent(int display, int64_t timestamp_ns,
+                              int64_t compositor_time_ns,
+                              uint32_t vsync_count) {
+  ATRACE_NAME("VSyncService::VSyncEvent");
+  std::lock_guard<std::mutex> autolock(mutex_);
+
+  if (display == HWC_DISPLAY_PRIMARY) {
+    last_vsync_ = current_vsync_;
+    current_vsync_ = timestamp_ns;
+    compositor_time_ns_ = compositor_time_ns;
+    current_vsync_count_ = vsync_count;
+
+    NotifyWaiters();
+    UpdateClients();
+  }
+}
+
+std::shared_ptr<Channel> VSyncService::OnChannelOpen(pdx::Message& message) {
+  const MessageInfo& info = message.GetInfo();
+
+  auto client = std::make_shared<VSyncChannel>(*this, info.pid, info.cid);
+  AddClient(client);
+
+  return client;
+}
+
+void VSyncService::OnChannelClose(pdx::Message& /*message*/,
+                                  const std::shared_ptr<Channel>& channel) {
+  auto client = std::static_pointer_cast<VSyncChannel>(channel);
+  if (!client) {
+    ALOGW("WARNING: VSyncChannel was NULL!!!\n");
+    return;
+  }
+
+  RemoveClient(client);
+}
+
+void VSyncService::AddWaiter(pdx::Message& message) {
+  std::lock_guard<std::mutex> autolock(mutex_);
+  std::unique_ptr<VSyncWaiter> waiter(new VSyncWaiter(message));
+  waiters_.push_back(std::move(waiter));
+}
+
+void VSyncService::AddClient(const std::shared_ptr<VSyncChannel>& client) {
+  std::lock_guard<std::mutex> autolock(mutex_);
+  clients_.push_back(client);
+}
+
+void VSyncService::RemoveClient(const std::shared_ptr<VSyncChannel>& client) {
+  std::lock_guard<std::mutex> autolock(mutex_);
+  clients_.remove(client);
+}
+
+// Private. Assumes mutex is held.
+void VSyncService::NotifyWaiters() {
+  ATRACE_NAME("VSyncService::NotifyWaiters");
+  auto first = waiters_.begin();
+  auto last = waiters_.end();
+
+  while (first != last) {
+    (*first)->Notify(current_vsync_);
+    waiters_.erase(first++);
+  }
+}
+
+// Private. Assumes mutex is held.
+void VSyncService::UpdateClients() {
+  ATRACE_NAME("VSyncService::UpdateClients");
+  auto first = clients_.begin();
+  auto last = clients_.end();
+
+  while (first != last) {
+    (*first)->Signal();
+    first++;
+  }
+}
+
+int VSyncService::HandleMessage(pdx::Message& message) {
+  switch (message.GetOp()) {
+    case DisplayVSyncRPC::Wait::Opcode:
+      AddWaiter(message);
+      return 0;
+
+    case DisplayVSyncRPC::GetLastTimestamp::Opcode:
+      DispatchRemoteMethod<DisplayVSyncRPC::GetLastTimestamp>(
+          *this, &VSyncService::OnGetLastTimestamp, message);
+      return 0;
+
+    case DisplayVSyncRPC::GetSchedInfo::Opcode:
+      DispatchRemoteMethod<DisplayVSyncRPC::GetSchedInfo>(
+          *this, &VSyncService::OnGetSchedInfo, message);
+      return 0;
+
+    case DisplayVSyncRPC::Acknowledge::Opcode:
+      DispatchRemoteMethod<DisplayVSyncRPC::Acknowledge>(
+          *this, &VSyncService::OnAcknowledge, message);
+      return 0;
+
+    default:
+      return Service::HandleMessage(message);
+  }
+}
+
+int64_t VSyncService::OnGetLastTimestamp(pdx::Message& message) {
+  auto client = std::static_pointer_cast<VSyncChannel>(message.GetChannel());
+  std::lock_guard<std::mutex> autolock(mutex_);
+
+  // Getting the timestamp has the side effect of ACKing.
+  client->Ack();
+  return current_vsync_;
+}
+
+VSyncSchedInfo VSyncService::OnGetSchedInfo(pdx::Message& message) {
+  auto client = std::static_pointer_cast<VSyncChannel>(message.GetChannel());
+  std::lock_guard<std::mutex> autolock(mutex_);
+
+  // Getting the timestamp has the side effect of ACKing.
+  client->Ack();
+
+  uint32_t next_vsync_count = current_vsync_count_ + 1;
+  int64_t current_time = GetSystemClockNs();
+  int64_t vsync_period_ns = 0;
+  int64_t next_warp;
+  if (current_vsync_ == 0 || last_vsync_ == 0) {
+    // Handle startup when current_vsync_ or last_vsync_ are 0.
+    // Normally should not happen because vsync_service is running before
+    // applications, but in case it does a sane time prevents applications
+    // from malfunctioning.
+    vsync_period_ns = 20000000;
+    next_warp = current_time;
+  } else {
+    // TODO(jbates) When we have an accurate reading of the true vsync
+    // period, use that instead of this estimated value.
+    vsync_period_ns = current_vsync_ - last_vsync_;
+    // Clamp the period, because when there are no surfaces the last_vsync_
+    // value will get stale. Note this is temporary and goes away as soon
+    // as we have an accurate vsync period reported by the system.
+    vsync_period_ns = std::min(vsync_period_ns, INT64_C(20000000));
+    next_warp = current_vsync_ + vsync_period_ns - compositor_time_ns_;
+    // If the request missed the present window, move up to the next vsync.
+    if (current_time > next_warp) {
+      next_warp += vsync_period_ns;
+      ++next_vsync_count;
+    }
+  }
+
+  return {vsync_period_ns, next_warp, next_vsync_count};
+}
+
+int VSyncService::OnAcknowledge(pdx::Message& message) {
+  auto client = std::static_pointer_cast<VSyncChannel>(message.GetChannel());
+  std::lock_guard<std::mutex> autolock(mutex_);
+  client->Ack();
+  return 0;
+}
+
+void VSyncWaiter::Notify(int64_t timestamp) {
+  timestamp_ = timestamp;
+  DispatchRemoteMethod<DisplayVSyncRPC::Wait>(*this, &VSyncWaiter::OnWait,
+                                              message_);
+}
+
+int64_t VSyncWaiter::OnWait(pdx::Message& /*message*/) { return timestamp_; }
+
+void VSyncChannel::Ack() {
+  ALOGD_IF(TRACE, "VSyncChannel::Ack: pid=%d cid=%d\n", pid_, cid_);
+  service_.ModifyChannelEvents(cid_, POLLPRI, 0);
+}
+
+void VSyncChannel::Signal() {
+  ALOGD_IF(TRACE, "VSyncChannel::Signal: pid=%d cid=%d\n", pid_, cid_);
+  service_.ModifyChannelEvents(cid_, 0, POLLPRI);
+}
+
+}  // namespace dvr
+}  // namespace android
diff --git a/libs/vr/libvrflinger/vsync_service.h b/libs/vr/libvrflinger/vsync_service.h
new file mode 100644
index 0000000..ba1d4df
--- /dev/null
+++ b/libs/vr/libvrflinger/vsync_service.h
@@ -0,0 +1,107 @@
+#ifndef ANDROID_DVR_SERVICES_DISPLAYD_VSYNC_SERVICE_H_
+#define ANDROID_DVR_SERVICES_DISPLAYD_VSYNC_SERVICE_H_
+
+#include <pdx/service.h>
+
+#include <list>
+#include <memory>
+#include <mutex>
+#include <thread>
+
+#include "display_service.h"
+
+namespace android {
+namespace dvr {
+
+// VSyncWaiter encapsulates a client blocked waiting for the next vsync.
+// It is used to enqueue the Message to reply to when the next vsync event
+// occurs.
+class VSyncWaiter {
+ public:
+  explicit VSyncWaiter(pdx::Message& message) : message_(std::move(message)) {}
+
+  void Notify(int64_t timestamp);
+
+ private:
+  int64_t OnWait(pdx::Message& message);
+
+  pdx::Message message_;
+  int64_t timestamp_ = 0;
+
+  VSyncWaiter(const VSyncWaiter&) = delete;
+  void operator=(const VSyncWaiter&) = delete;
+};
+
+// VSyncChannel manages the service-side per-client context for each client
+// using the service.
+class VSyncChannel : public pdx::Channel {
+ public:
+  VSyncChannel(pdx::Service& service, int pid, int cid)
+      : service_(service), pid_(pid), cid_(cid) {}
+
+  void Ack();
+  void Signal();
+
+ private:
+  pdx::Service& service_;
+  pid_t pid_;
+  int cid_;
+
+  VSyncChannel(const VSyncChannel&) = delete;
+  void operator=(const VSyncChannel&) = delete;
+};
+
+// VSyncService implements the displayd vsync service over ServiceFS.
+class VSyncService : public pdx::ServiceBase<VSyncService> {
+ public:
+  ~VSyncService() override;
+
+  int HandleMessage(pdx::Message& message) override;
+
+  std::shared_ptr<pdx::Channel> OnChannelOpen(pdx::Message& message) override;
+  void OnChannelClose(pdx::Message& message,
+                      const std::shared_ptr<pdx::Channel>& channel) override;
+
+  // Called by the hardware composer HAL, or similar,
+  // whenever a vsync event occurs.
+  // |compositor_time_ns| is the number of ns before the next vsync when the
+  // compositor will preempt the GPU to do EDS and lens warp.
+  void VSyncEvent(int display, int64_t timestamp_ns, int64_t compositor_time_ns,
+                  uint32_t vsync_count);
+
+ private:
+  friend BASE;
+
+  VSyncService();
+
+  int64_t OnGetLastTimestamp(pdx::Message& message);
+  VSyncSchedInfo OnGetSchedInfo(pdx::Message& message);
+  int OnAcknowledge(pdx::Message& message);
+
+  void NotifierThreadFunction();
+
+  void AddWaiter(pdx::Message& message);
+  void NotifyWaiters();
+  void UpdateClients();
+
+  void AddClient(const std::shared_ptr<VSyncChannel>& client);
+  void RemoveClient(const std::shared_ptr<VSyncChannel>& client);
+
+  int64_t last_vsync_;
+  int64_t current_vsync_;
+  int64_t compositor_time_ns_;
+  uint32_t current_vsync_count_;
+
+  std::mutex mutex_;
+
+  std::list<std::unique_ptr<VSyncWaiter>> waiters_;
+  std::list<std::shared_ptr<VSyncChannel>> clients_;
+
+  VSyncService(const VSyncService&) = delete;
+  void operator=(VSyncService&) = delete;
+};
+
+}  // namespace dvr
+}  // namespace android
+
+#endif  // ANDROID_DVR_SERVICES_DISPLAYD_VSYNC_SERVICE_H_