Move Choreographer impl to new file.

Separates implementation from the API so it is neater.

Bug: 255838011
Test: make, flash, atest ChoreographerNativeTest

Change-Id: I8ac97ed4ebc1a4ed9d6315a473e178bf3d655252
diff --git a/libs/nativedisplay/AChoreographer.cpp b/libs/nativedisplay/AChoreographer.cpp
index 539cbaa..e64165f 100644
--- a/libs/nativedisplay/AChoreographer.cpp
+++ b/libs/nativedisplay/AChoreographer.cpp
@@ -14,13 +14,10 @@
  * limitations under the License.
  */
 
-#define LOG_TAG "Choreographer"
-//#define LOG_NDEBUG 0
-
 #include <android-base/thread_annotations.h>
 #include <android/gui/ISurfaceComposer.h>
-#include <gui/DisplayEventDispatcher.h>
 #include <jni.h>
+#include <nativedisplay/Choreographer.h>
 #include <private/android/choreographer.h>
 #include <utils/Looper.h>
 #include <utils/Timers.h>
@@ -31,444 +28,9 @@
 #include <queue>
 #include <thread>
 
-namespace {
-struct {
-    // Global JVM that is provided by zygote
-    JavaVM* jvm = nullptr;
-    struct {
-        jclass clazz;
-        jmethodID getInstance;
-        jmethodID registerNativeChoreographerForRefreshRateCallbacks;
-        jmethodID unregisterNativeChoreographerForRefreshRateCallbacks;
-    } displayManagerGlobal;
-} gJni;
+#undef LOG_TAG
+#define LOG_TAG "AChoreographer"
 
-// Gets the JNIEnv* for this thread, and performs one-off initialization if we
-// have never retrieved a JNIEnv* pointer before.
-JNIEnv* getJniEnv() {
-    if (gJni.jvm == nullptr) {
-        ALOGW("AChoreographer: No JVM provided!");
-        return nullptr;
-    }
-
-    JNIEnv* env = nullptr;
-    if (gJni.jvm->GetEnv((void**)&env, JNI_VERSION_1_4) != JNI_OK) {
-        ALOGD("Attaching thread to JVM for AChoreographer");
-        JavaVMAttachArgs args = {JNI_VERSION_1_4, "AChoreographer_env", NULL};
-        jint attachResult = gJni.jvm->AttachCurrentThreadAsDaemon(&env, (void*)&args);
-        if (attachResult != JNI_OK) {
-            ALOGE("Unable to attach thread. Error: %d", attachResult);
-            return nullptr;
-        }
-    }
-    if (env == nullptr) {
-        ALOGW("AChoreographer: No JNI env available!");
-    }
-    return env;
-}
-
-inline const char* toString(bool value) {
-    return value ? "true" : "false";
-}
-} // namespace
-
-namespace android {
-using gui::VsyncEventData;
-
-struct FrameCallback {
-    AChoreographer_frameCallback callback;
-    AChoreographer_frameCallback64 callback64;
-    AChoreographer_vsyncCallback vsyncCallback;
-    void* data;
-    nsecs_t dueTime;
-
-    inline bool operator<(const FrameCallback& rhs) const {
-        // Note that this is intentionally flipped because we want callbacks due sooner to be at
-        // the head of the queue
-        return dueTime > rhs.dueTime;
-    }
-};
-
-struct RefreshRateCallback {
-    AChoreographer_refreshRateCallback callback;
-    void* data;
-    bool firstCallbackFired = false;
-};
-
-class Choreographer;
-
-/**
- * Implementation of AChoreographerFrameCallbackData.
- */
-struct ChoreographerFrameCallbackDataImpl {
-    int64_t frameTimeNanos{0};
-
-    VsyncEventData vsyncEventData;
-
-    const Choreographer* choreographer;
-};
-
-struct {
-    std::mutex lock;
-    std::vector<Choreographer*> ptrs GUARDED_BY(lock);
-    std::map<AVsyncId, int64_t> startTimes GUARDED_BY(lock);
-    bool registeredToDisplayManager GUARDED_BY(lock) = false;
-
-    std::atomic<nsecs_t> mLastKnownVsync = -1;
-} gChoreographers;
-
-class Choreographer : public DisplayEventDispatcher, public MessageHandler {
-public:
-    explicit Choreographer(const sp<Looper>& looper) EXCLUDES(gChoreographers.lock);
-    void postFrameCallbackDelayed(AChoreographer_frameCallback cb,
-                                  AChoreographer_frameCallback64 cb64,
-                                  AChoreographer_vsyncCallback vsyncCallback, void* data,
-                                  nsecs_t delay);
-    void registerRefreshRateCallback(AChoreographer_refreshRateCallback cb, void* data)
-            EXCLUDES(gChoreographers.lock);
-    void unregisterRefreshRateCallback(AChoreographer_refreshRateCallback cb, void* data);
-    // Drains the queue of pending vsync periods and dispatches refresh rate
-    // updates to callbacks.
-    // The assumption is that this method is only called on a single
-    // processing thread, either by looper or by AChoreographer_handleEvents
-    void handleRefreshRateUpdates();
-    void scheduleLatestConfigRequest();
-
-    enum {
-        MSG_SCHEDULE_CALLBACKS = 0,
-        MSG_SCHEDULE_VSYNC = 1,
-        MSG_HANDLE_REFRESH_RATE_UPDATES = 2,
-    };
-    virtual void handleMessage(const Message& message) override;
-
-    static Choreographer* getForThread();
-    virtual ~Choreographer() override EXCLUDES(gChoreographers.lock);
-    int64_t getFrameInterval() const;
-    bool inCallback() const;
-
-private:
-    Choreographer(const Choreographer&) = delete;
-
-    void dispatchVsync(nsecs_t timestamp, PhysicalDisplayId displayId, uint32_t count,
-                       VsyncEventData vsyncEventData) override;
-    void dispatchHotplug(nsecs_t timestamp, PhysicalDisplayId displayId, bool connected) override;
-    void dispatchModeChanged(nsecs_t timestamp, PhysicalDisplayId displayId, int32_t modeId,
-                             nsecs_t vsyncPeriod) override;
-    void dispatchNullEvent(nsecs_t, PhysicalDisplayId) override;
-    void dispatchFrameRateOverrides(nsecs_t timestamp, PhysicalDisplayId displayId,
-                                    std::vector<FrameRateOverride> overrides) override;
-
-    void scheduleCallbacks();
-
-    ChoreographerFrameCallbackDataImpl createFrameCallbackData(nsecs_t timestamp) const;
-    void registerStartTime() const;
-
-    std::mutex mLock;
-    // Protected by mLock
-    std::priority_queue<FrameCallback> mFrameCallbacks;
-    std::vector<RefreshRateCallback> mRefreshRateCallbacks;
-
-    nsecs_t mLatestVsyncPeriod = -1;
-    VsyncEventData mLastVsyncEventData;
-    bool mInCallback = false;
-
-    const sp<Looper> mLooper;
-    const std::thread::id mThreadId;
-
-    // Approximation of num_threads_using_choreographer * num_frames_of_history with leeway.
-    static constexpr size_t kMaxStartTimes = 250;
-};
-
-static thread_local Choreographer* gChoreographer;
-Choreographer* Choreographer::getForThread() {
-    if (gChoreographer == nullptr) {
-        sp<Looper> looper = Looper::getForThread();
-        if (!looper.get()) {
-            ALOGW("No looper prepared for thread");
-            return nullptr;
-        }
-        gChoreographer = new Choreographer(looper);
-        status_t result = gChoreographer->initialize();
-        if (result != OK) {
-            ALOGW("Failed to initialize");
-            return nullptr;
-        }
-    }
-    return gChoreographer;
-}
-
-Choreographer::Choreographer(const sp<Looper>& looper)
-      : DisplayEventDispatcher(looper, gui::ISurfaceComposer::VsyncSource::eVsyncSourceApp),
-        mLooper(looper),
-        mThreadId(std::this_thread::get_id()) {
-    std::lock_guard<std::mutex> _l(gChoreographers.lock);
-    gChoreographers.ptrs.push_back(this);
-}
-
-Choreographer::~Choreographer() {
-    std::lock_guard<std::mutex> _l(gChoreographers.lock);
-    gChoreographers.ptrs.erase(std::remove_if(gChoreographers.ptrs.begin(),
-                                              gChoreographers.ptrs.end(),
-                                              [=](Choreographer* c) { return c == this; }),
-                               gChoreographers.ptrs.end());
-    // Only poke DisplayManagerGlobal to unregister if we previously registered
-    // callbacks.
-    if (gChoreographers.ptrs.empty() && gChoreographers.registeredToDisplayManager) {
-        gChoreographers.registeredToDisplayManager = false;
-        JNIEnv* env = getJniEnv();
-        if (env == nullptr) {
-            ALOGW("JNI environment is unavailable, skipping choreographer cleanup");
-            return;
-        }
-        jobject dmg = env->CallStaticObjectMethod(gJni.displayManagerGlobal.clazz,
-                                                  gJni.displayManagerGlobal.getInstance);
-        if (dmg == nullptr) {
-            ALOGW("DMS is not initialized yet, skipping choreographer cleanup");
-        } else {
-            env->CallVoidMethod(dmg,
-                                gJni.displayManagerGlobal
-                                        .unregisterNativeChoreographerForRefreshRateCallbacks);
-            env->DeleteLocalRef(dmg);
-        }
-    }
-}
-
-void Choreographer::postFrameCallbackDelayed(AChoreographer_frameCallback cb,
-                                             AChoreographer_frameCallback64 cb64,
-                                             AChoreographer_vsyncCallback vsyncCallback, void* data,
-                                             nsecs_t delay) {
-    nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
-    FrameCallback callback{cb, cb64, vsyncCallback, data, now + delay};
-    {
-        std::lock_guard<std::mutex> _l{mLock};
-        mFrameCallbacks.push(callback);
-    }
-    if (callback.dueTime <= now) {
-        if (std::this_thread::get_id() != mThreadId) {
-            if (mLooper != nullptr) {
-                Message m{MSG_SCHEDULE_VSYNC};
-                mLooper->sendMessage(this, m);
-            } else {
-                scheduleVsync();
-            }
-        } else {
-            scheduleVsync();
-        }
-    } else {
-        if (mLooper != nullptr) {
-            Message m{MSG_SCHEDULE_CALLBACKS};
-            mLooper->sendMessageDelayed(delay, this, m);
-        } else {
-            scheduleCallbacks();
-        }
-    }
-}
-
-void Choreographer::registerRefreshRateCallback(AChoreographer_refreshRateCallback cb, void* data) {
-    std::lock_guard<std::mutex> _l{mLock};
-    for (const auto& callback : mRefreshRateCallbacks) {
-        // Don't re-add callbacks.
-        if (cb == callback.callback && data == callback.data) {
-            return;
-        }
-    }
-    mRefreshRateCallbacks.emplace_back(
-            RefreshRateCallback{.callback = cb, .data = data, .firstCallbackFired = false});
-    bool needsRegistration = false;
-    {
-        std::lock_guard<std::mutex> _l2(gChoreographers.lock);
-        needsRegistration = !gChoreographers.registeredToDisplayManager;
-    }
-    if (needsRegistration) {
-        JNIEnv* env = getJniEnv();
-        if (env == nullptr) {
-            ALOGW("JNI environment is unavailable, skipping registration");
-            return;
-        }
-        jobject dmg = env->CallStaticObjectMethod(gJni.displayManagerGlobal.clazz,
-                                                  gJni.displayManagerGlobal.getInstance);
-        if (dmg == nullptr) {
-            ALOGW("DMS is not initialized yet: skipping registration");
-            return;
-        } else {
-            env->CallVoidMethod(dmg,
-                                gJni.displayManagerGlobal
-                                        .registerNativeChoreographerForRefreshRateCallbacks,
-                                reinterpret_cast<int64_t>(this));
-            env->DeleteLocalRef(dmg);
-            {
-                std::lock_guard<std::mutex> _l2(gChoreographers.lock);
-                gChoreographers.registeredToDisplayManager = true;
-            }
-        }
-    } else {
-        scheduleLatestConfigRequest();
-    }
-}
-
-void Choreographer::unregisterRefreshRateCallback(AChoreographer_refreshRateCallback cb,
-                                                  void* data) {
-    std::lock_guard<std::mutex> _l{mLock};
-    mRefreshRateCallbacks.erase(std::remove_if(mRefreshRateCallbacks.begin(),
-                                               mRefreshRateCallbacks.end(),
-                                               [&](const RefreshRateCallback& callback) {
-                                                   return cb == callback.callback &&
-                                                           data == callback.data;
-                                               }),
-                                mRefreshRateCallbacks.end());
-}
-
-void Choreographer::scheduleLatestConfigRequest() {
-    if (mLooper != nullptr) {
-        Message m{MSG_HANDLE_REFRESH_RATE_UPDATES};
-        mLooper->sendMessage(this, m);
-    } else {
-        // If the looper thread is detached from Choreographer, then refresh rate
-        // changes will be handled in AChoreographer_handlePendingEvents, so we
-        // need to wake up the looper thread by writing to the write-end of the
-        // socket the looper is listening on.
-        // Fortunately, these events are small so sending packets across the
-        // socket should be atomic across processes.
-        DisplayEventReceiver::Event event;
-        event.header =
-                DisplayEventReceiver::Event::Header{DisplayEventReceiver::DISPLAY_EVENT_NULL,
-                                                    PhysicalDisplayId::fromPort(0), systemTime()};
-        injectEvent(event);
-    }
-}
-
-void Choreographer::scheduleCallbacks() {
-    const nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
-    nsecs_t dueTime;
-    {
-        std::lock_guard<std::mutex> _l{mLock};
-        // If there are no pending callbacks then don't schedule a vsync
-        if (mFrameCallbacks.empty()) {
-            return;
-        }
-        dueTime = mFrameCallbacks.top().dueTime;
-    }
-
-    if (dueTime <= now) {
-        ALOGV("choreographer %p ~ scheduling vsync", this);
-        scheduleVsync();
-        return;
-    }
-}
-
-void Choreographer::handleRefreshRateUpdates() {
-    std::vector<RefreshRateCallback> callbacks{};
-    const nsecs_t pendingPeriod = gChoreographers.mLastKnownVsync.load();
-    const nsecs_t lastPeriod = mLatestVsyncPeriod;
-    if (pendingPeriod > 0) {
-        mLatestVsyncPeriod = pendingPeriod;
-    }
-    {
-        std::lock_guard<std::mutex> _l{mLock};
-        for (auto& cb : mRefreshRateCallbacks) {
-            callbacks.push_back(cb);
-            cb.firstCallbackFired = true;
-        }
-    }
-
-    for (auto& cb : callbacks) {
-        if (!cb.firstCallbackFired || (pendingPeriod > 0 && pendingPeriod != lastPeriod)) {
-            cb.callback(pendingPeriod, cb.data);
-        }
-    }
-}
-
-// TODO(b/74619554): The PhysicalDisplayId is ignored because SF only emits VSYNC events for the
-// internal display and DisplayEventReceiver::requestNextVsync only allows requesting VSYNC for
-// the internal display implicitly.
-void Choreographer::dispatchVsync(nsecs_t timestamp, PhysicalDisplayId, uint32_t,
-                                  VsyncEventData vsyncEventData) {
-    std::vector<FrameCallback> callbacks{};
-    {
-        std::lock_guard<std::mutex> _l{mLock};
-        nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
-        while (!mFrameCallbacks.empty() && mFrameCallbacks.top().dueTime < now) {
-            callbacks.push_back(mFrameCallbacks.top());
-            mFrameCallbacks.pop();
-        }
-    }
-    mLastVsyncEventData = vsyncEventData;
-    for (const auto& cb : callbacks) {
-        if (cb.vsyncCallback != nullptr) {
-            const ChoreographerFrameCallbackDataImpl frameCallbackData =
-                    createFrameCallbackData(timestamp);
-            registerStartTime();
-            mInCallback = true;
-            cb.vsyncCallback(reinterpret_cast<const AChoreographerFrameCallbackData*>(
-                                     &frameCallbackData),
-                             cb.data);
-            mInCallback = false;
-        } else if (cb.callback64 != nullptr) {
-            cb.callback64(timestamp, cb.data);
-        } else if (cb.callback != nullptr) {
-            cb.callback(timestamp, cb.data);
-        }
-    }
-}
-
-void Choreographer::dispatchHotplug(nsecs_t, PhysicalDisplayId displayId, bool connected) {
-    ALOGV("choreographer %p ~ received hotplug event (displayId=%s, connected=%s), ignoring.", this,
-          to_string(displayId).c_str(), toString(connected));
-}
-
-void Choreographer::dispatchModeChanged(nsecs_t, PhysicalDisplayId, int32_t, nsecs_t) {
-    LOG_ALWAYS_FATAL("dispatchModeChanged was called but was never registered");
-}
-
-void Choreographer::dispatchFrameRateOverrides(nsecs_t, PhysicalDisplayId,
-                                               std::vector<FrameRateOverride>) {
-    LOG_ALWAYS_FATAL("dispatchFrameRateOverrides was called but was never registered");
-}
-
-void Choreographer::dispatchNullEvent(nsecs_t, PhysicalDisplayId) {
-    ALOGV("choreographer %p ~ received null event.", this);
-    handleRefreshRateUpdates();
-}
-
-void Choreographer::handleMessage(const Message& message) {
-    switch (message.what) {
-        case MSG_SCHEDULE_CALLBACKS:
-            scheduleCallbacks();
-            break;
-        case MSG_SCHEDULE_VSYNC:
-            scheduleVsync();
-            break;
-        case MSG_HANDLE_REFRESH_RATE_UPDATES:
-            handleRefreshRateUpdates();
-            break;
-    }
-}
-
-int64_t Choreographer::getFrameInterval() const {
-    return mLastVsyncEventData.frameInterval;
-}
-
-bool Choreographer::inCallback() const {
-    return mInCallback;
-}
-
-ChoreographerFrameCallbackDataImpl Choreographer::createFrameCallbackData(nsecs_t timestamp) const {
-    return {.frameTimeNanos = timestamp,
-            .vsyncEventData = mLastVsyncEventData,
-            .choreographer = this};
-}
-
-void Choreographer::registerStartTime() const {
-    std::scoped_lock _l(gChoreographers.lock);
-    for (VsyncEventData::FrameTimeline frameTimeline : mLastVsyncEventData.frameTimelines) {
-        while (gChoreographers.startTimes.size() >= kMaxStartTimes) {
-            gChoreographers.startTimes.erase(gChoreographers.startTimes.begin());
-        }
-        gChoreographers.startTimes[frameTimeline.vsyncId] = systemTime(SYSTEM_TIME_MONOTONIC);
-    }
-}
-
-} // namespace android
 using namespace android;
 
 static inline Choreographer* AChoreographer_to_Choreographer(AChoreographer* choreographer) {
@@ -488,27 +50,12 @@
 
 // Glue for private C api
 namespace android {
-void AChoreographer_signalRefreshRateCallbacks(nsecs_t vsyncPeriod) EXCLUDES(gChoreographers.lock) {
-    std::lock_guard<std::mutex> _l(gChoreographers.lock);
-    gChoreographers.mLastKnownVsync.store(vsyncPeriod);
-    for (auto c : gChoreographers.ptrs) {
-        c->scheduleLatestConfigRequest();
-    }
+void AChoreographer_signalRefreshRateCallbacks(nsecs_t vsyncPeriod) {
+    Choreographer::signalRefreshRateCallbacks(vsyncPeriod);
 }
 
 void AChoreographer_initJVM(JNIEnv* env) {
-    env->GetJavaVM(&gJni.jvm);
-    // Now we need to find the java classes.
-    jclass dmgClass = env->FindClass("android/hardware/display/DisplayManagerGlobal");
-    gJni.displayManagerGlobal.clazz = static_cast<jclass>(env->NewGlobalRef(dmgClass));
-    gJni.displayManagerGlobal.getInstance =
-            env->GetStaticMethodID(dmgClass, "getInstance",
-                                   "()Landroid/hardware/display/DisplayManagerGlobal;");
-    gJni.displayManagerGlobal.registerNativeChoreographerForRefreshRateCallbacks =
-            env->GetMethodID(dmgClass, "registerNativeChoreographerForRefreshRateCallbacks", "()V");
-    gJni.displayManagerGlobal.unregisterNativeChoreographerForRefreshRateCallbacks =
-            env->GetMethodID(dmgClass, "unregisterNativeChoreographerForRefreshRateCallbacks",
-                             "()V");
+    Choreographer::initJVM(env);
 }
 
 AChoreographer* AChoreographer_routeGetInstance() {
@@ -583,13 +130,7 @@
 }
 
 int64_t AChoreographer_getStartTimeNanosForVsyncId(AVsyncId vsyncId) {
-    std::scoped_lock _l(gChoreographers.lock);
-    const auto iter = gChoreographers.startTimes.find(vsyncId);
-    if (iter == gChoreographers.startTimes.end()) {
-        ALOGW("Start time was not found for vsync id: %" PRId64, vsyncId);
-        return 0;
-    }
-    return iter->second;
+    return Choreographer::getStartTimeNanosForVsyncId(vsyncId);
 }
 
 } // namespace android
diff --git a/libs/nativedisplay/Android.bp b/libs/nativedisplay/Android.bp
index 8d8a2bc..70de33d 100644
--- a/libs/nativedisplay/Android.bp
+++ b/libs/nativedisplay/Android.bp
@@ -56,6 +56,7 @@
         ":libgui_frame_event_aidl",
         "AChoreographer.cpp",
         "ADisplay.cpp",
+        "Choreographer.cpp",
         "surfacetexture/surface_texture.cpp",
         "surfacetexture/SurfaceTexture.cpp",
         "surfacetexture/ImageConsumer.cpp",
diff --git a/libs/nativedisplay/Choreographer.cpp b/libs/nativedisplay/Choreographer.cpp
new file mode 100644
index 0000000..01e9f04
--- /dev/null
+++ b/libs/nativedisplay/Choreographer.cpp
@@ -0,0 +1,390 @@
+/*
+ * Copyright 2022 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.
+ */
+
+// #define LOG_NDEBUG 0
+
+#include <jni.h>
+#include <nativedisplay/Choreographer.h>
+
+#undef LOG_TAG
+#define LOG_TAG "AChoreographer"
+
+namespace {
+struct {
+    // Global JVM that is provided by zygote
+    JavaVM* jvm = nullptr;
+    struct {
+        jclass clazz;
+        jmethodID getInstance;
+        jmethodID registerNativeChoreographerForRefreshRateCallbacks;
+        jmethodID unregisterNativeChoreographerForRefreshRateCallbacks;
+    } displayManagerGlobal;
+} gJni;
+
+// Gets the JNIEnv* for this thread, and performs one-off initialization if we
+// have never retrieved a JNIEnv* pointer before.
+JNIEnv* getJniEnv() {
+    if (gJni.jvm == nullptr) {
+        ALOGW("AChoreographer: No JVM provided!");
+        return nullptr;
+    }
+
+    JNIEnv* env = nullptr;
+    if (gJni.jvm->GetEnv((void**)&env, JNI_VERSION_1_4) != JNI_OK) {
+        ALOGD("Attaching thread to JVM for AChoreographer");
+        JavaVMAttachArgs args = {JNI_VERSION_1_4, "AChoreographer_env", NULL};
+        jint attachResult = gJni.jvm->AttachCurrentThreadAsDaemon(&env, (void*)&args);
+        if (attachResult != JNI_OK) {
+            ALOGE("Unable to attach thread. Error: %d", attachResult);
+            return nullptr;
+        }
+    }
+    if (env == nullptr) {
+        ALOGW("AChoreographer: No JNI env available!");
+    }
+    return env;
+}
+
+inline const char* toString(bool value) {
+    return value ? "true" : "false";
+}
+} // namespace
+
+namespace android {
+
+Choreographer::Context Choreographer::gChoreographers;
+
+static thread_local Choreographer* gChoreographer;
+
+void Choreographer::initJVM(JNIEnv* env) {
+    env->GetJavaVM(&gJni.jvm);
+    // Now we need to find the java classes.
+    jclass dmgClass = env->FindClass("android/hardware/display/DisplayManagerGlobal");
+    gJni.displayManagerGlobal.clazz = static_cast<jclass>(env->NewGlobalRef(dmgClass));
+    gJni.displayManagerGlobal.getInstance =
+            env->GetStaticMethodID(dmgClass, "getInstance",
+                                   "()Landroid/hardware/display/DisplayManagerGlobal;");
+    gJni.displayManagerGlobal.registerNativeChoreographerForRefreshRateCallbacks =
+            env->GetMethodID(dmgClass, "registerNativeChoreographerForRefreshRateCallbacks", "()V");
+    gJni.displayManagerGlobal.unregisterNativeChoreographerForRefreshRateCallbacks =
+            env->GetMethodID(dmgClass, "unregisterNativeChoreographerForRefreshRateCallbacks",
+                             "()V");
+}
+
+Choreographer* Choreographer::getForThread() {
+    if (gChoreographer == nullptr) {
+        sp<Looper> looper = Looper::getForThread();
+        if (!looper.get()) {
+            ALOGW("No looper prepared for thread");
+            return nullptr;
+        }
+        gChoreographer = new Choreographer(looper);
+        status_t result = gChoreographer->initialize();
+        if (result != OK) {
+            ALOGW("Failed to initialize");
+            return nullptr;
+        }
+    }
+    return gChoreographer;
+}
+
+Choreographer::Choreographer(const sp<Looper>& looper)
+      : DisplayEventDispatcher(looper, gui::ISurfaceComposer::VsyncSource::eVsyncSourceApp),
+        mLooper(looper),
+        mThreadId(std::this_thread::get_id()) {
+    std::lock_guard<std::mutex> _l(gChoreographers.lock);
+    gChoreographers.ptrs.push_back(this);
+}
+
+Choreographer::~Choreographer() {
+    std::lock_guard<std::mutex> _l(gChoreographers.lock);
+    gChoreographers.ptrs.erase(std::remove_if(gChoreographers.ptrs.begin(),
+                                              gChoreographers.ptrs.end(),
+                                              [=](Choreographer* c) { return c == this; }),
+                               gChoreographers.ptrs.end());
+    // Only poke DisplayManagerGlobal to unregister if we previously registered
+    // callbacks.
+    if (gChoreographers.ptrs.empty() && gChoreographers.registeredToDisplayManager) {
+        gChoreographers.registeredToDisplayManager = false;
+        JNIEnv* env = getJniEnv();
+        if (env == nullptr) {
+            ALOGW("JNI environment is unavailable, skipping choreographer cleanup");
+            return;
+        }
+        jobject dmg = env->CallStaticObjectMethod(gJni.displayManagerGlobal.clazz,
+                                                  gJni.displayManagerGlobal.getInstance);
+        if (dmg == nullptr) {
+            ALOGW("DMS is not initialized yet, skipping choreographer cleanup");
+        } else {
+            env->CallVoidMethod(dmg,
+                                gJni.displayManagerGlobal
+                                        .unregisterNativeChoreographerForRefreshRateCallbacks);
+            env->DeleteLocalRef(dmg);
+        }
+    }
+}
+
+void Choreographer::postFrameCallbackDelayed(AChoreographer_frameCallback cb,
+                                             AChoreographer_frameCallback64 cb64,
+                                             AChoreographer_vsyncCallback vsyncCallback, void* data,
+                                             nsecs_t delay) {
+    nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
+    FrameCallback callback{cb, cb64, vsyncCallback, data, now + delay};
+    {
+        std::lock_guard<std::mutex> _l{mLock};
+        mFrameCallbacks.push(callback);
+    }
+    if (callback.dueTime <= now) {
+        if (std::this_thread::get_id() != mThreadId) {
+            if (mLooper != nullptr) {
+                Message m{MSG_SCHEDULE_VSYNC};
+                mLooper->sendMessage(this, m);
+            } else {
+                scheduleVsync();
+            }
+        } else {
+            scheduleVsync();
+        }
+    } else {
+        if (mLooper != nullptr) {
+            Message m{MSG_SCHEDULE_CALLBACKS};
+            mLooper->sendMessageDelayed(delay, this, m);
+        } else {
+            scheduleCallbacks();
+        }
+    }
+}
+
+void Choreographer::registerRefreshRateCallback(AChoreographer_refreshRateCallback cb, void* data) {
+    std::lock_guard<std::mutex> _l{mLock};
+    for (const auto& callback : mRefreshRateCallbacks) {
+        // Don't re-add callbacks.
+        if (cb == callback.callback && data == callback.data) {
+            return;
+        }
+    }
+    mRefreshRateCallbacks.emplace_back(
+            RefreshRateCallback{.callback = cb, .data = data, .firstCallbackFired = false});
+    bool needsRegistration = false;
+    {
+        std::lock_guard<std::mutex> _l2(gChoreographers.lock);
+        needsRegistration = !gChoreographers.registeredToDisplayManager;
+    }
+    if (needsRegistration) {
+        JNIEnv* env = getJniEnv();
+        if (env == nullptr) {
+            ALOGW("JNI environment is unavailable, skipping registration");
+            return;
+        }
+        jobject dmg = env->CallStaticObjectMethod(gJni.displayManagerGlobal.clazz,
+                                                  gJni.displayManagerGlobal.getInstance);
+        if (dmg == nullptr) {
+            ALOGW("DMS is not initialized yet: skipping registration");
+            return;
+        } else {
+            env->CallVoidMethod(dmg,
+                                gJni.displayManagerGlobal
+                                        .registerNativeChoreographerForRefreshRateCallbacks,
+                                reinterpret_cast<int64_t>(this));
+            env->DeleteLocalRef(dmg);
+            {
+                std::lock_guard<std::mutex> _l2(gChoreographers.lock);
+                gChoreographers.registeredToDisplayManager = true;
+            }
+        }
+    } else {
+        scheduleLatestConfigRequest();
+    }
+}
+
+void Choreographer::unregisterRefreshRateCallback(AChoreographer_refreshRateCallback cb,
+                                                  void* data) {
+    std::lock_guard<std::mutex> _l{mLock};
+    mRefreshRateCallbacks.erase(std::remove_if(mRefreshRateCallbacks.begin(),
+                                               mRefreshRateCallbacks.end(),
+                                               [&](const RefreshRateCallback& callback) {
+                                                   return cb == callback.callback &&
+                                                           data == callback.data;
+                                               }),
+                                mRefreshRateCallbacks.end());
+}
+
+void Choreographer::scheduleLatestConfigRequest() {
+    if (mLooper != nullptr) {
+        Message m{MSG_HANDLE_REFRESH_RATE_UPDATES};
+        mLooper->sendMessage(this, m);
+    } else {
+        // If the looper thread is detached from Choreographer, then refresh rate
+        // changes will be handled in AChoreographer_handlePendingEvents, so we
+        // need to wake up the looper thread by writing to the write-end of the
+        // socket the looper is listening on.
+        // Fortunately, these events are small so sending packets across the
+        // socket should be atomic across processes.
+        DisplayEventReceiver::Event event;
+        event.header =
+                DisplayEventReceiver::Event::Header{DisplayEventReceiver::DISPLAY_EVENT_NULL,
+                                                    PhysicalDisplayId::fromPort(0), systemTime()};
+        injectEvent(event);
+    }
+}
+
+void Choreographer::scheduleCallbacks() {
+    const nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
+    nsecs_t dueTime;
+    {
+        std::lock_guard<std::mutex> _l{mLock};
+        // If there are no pending callbacks then don't schedule a vsync
+        if (mFrameCallbacks.empty()) {
+            return;
+        }
+        dueTime = mFrameCallbacks.top().dueTime;
+    }
+
+    if (dueTime <= now) {
+        ALOGV("choreographer %p ~ scheduling vsync", this);
+        scheduleVsync();
+        return;
+    }
+}
+
+void Choreographer::handleRefreshRateUpdates() {
+    std::vector<RefreshRateCallback> callbacks{};
+    const nsecs_t pendingPeriod = gChoreographers.mLastKnownVsync.load();
+    const nsecs_t lastPeriod = mLatestVsyncPeriod;
+    if (pendingPeriod > 0) {
+        mLatestVsyncPeriod = pendingPeriod;
+    }
+    {
+        std::lock_guard<std::mutex> _l{mLock};
+        for (auto& cb : mRefreshRateCallbacks) {
+            callbacks.push_back(cb);
+            cb.firstCallbackFired = true;
+        }
+    }
+
+    for (auto& cb : callbacks) {
+        if (!cb.firstCallbackFired || (pendingPeriod > 0 && pendingPeriod != lastPeriod)) {
+            cb.callback(pendingPeriod, cb.data);
+        }
+    }
+}
+
+void Choreographer::dispatchVsync(nsecs_t timestamp, PhysicalDisplayId, uint32_t,
+                                  VsyncEventData vsyncEventData) {
+    std::vector<FrameCallback> callbacks{};
+    {
+        std::lock_guard<std::mutex> _l{mLock};
+        nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
+        while (!mFrameCallbacks.empty() && mFrameCallbacks.top().dueTime < now) {
+            callbacks.push_back(mFrameCallbacks.top());
+            mFrameCallbacks.pop();
+        }
+    }
+    mLastVsyncEventData = vsyncEventData;
+    for (const auto& cb : callbacks) {
+        if (cb.vsyncCallback != nullptr) {
+            const ChoreographerFrameCallbackDataImpl frameCallbackData =
+                    createFrameCallbackData(timestamp);
+            registerStartTime();
+            mInCallback = true;
+            cb.vsyncCallback(reinterpret_cast<const AChoreographerFrameCallbackData*>(
+                                     &frameCallbackData),
+                             cb.data);
+            mInCallback = false;
+        } else if (cb.callback64 != nullptr) {
+            cb.callback64(timestamp, cb.data);
+        } else if (cb.callback != nullptr) {
+            cb.callback(timestamp, cb.data);
+        }
+    }
+}
+
+void Choreographer::dispatchHotplug(nsecs_t, PhysicalDisplayId displayId, bool connected) {
+    ALOGV("choreographer %p ~ received hotplug event (displayId=%s, connected=%s), ignoring.", this,
+          to_string(displayId).c_str(), toString(connected));
+}
+
+void Choreographer::dispatchModeChanged(nsecs_t, PhysicalDisplayId, int32_t, nsecs_t) {
+    LOG_ALWAYS_FATAL("dispatchModeChanged was called but was never registered");
+}
+
+void Choreographer::dispatchFrameRateOverrides(nsecs_t, PhysicalDisplayId,
+                                               std::vector<FrameRateOverride>) {
+    LOG_ALWAYS_FATAL("dispatchFrameRateOverrides was called but was never registered");
+}
+
+void Choreographer::dispatchNullEvent(nsecs_t, PhysicalDisplayId) {
+    ALOGV("choreographer %p ~ received null event.", this);
+    handleRefreshRateUpdates();
+}
+
+void Choreographer::handleMessage(const Message& message) {
+    switch (message.what) {
+        case MSG_SCHEDULE_CALLBACKS:
+            scheduleCallbacks();
+            break;
+        case MSG_SCHEDULE_VSYNC:
+            scheduleVsync();
+            break;
+        case MSG_HANDLE_REFRESH_RATE_UPDATES:
+            handleRefreshRateUpdates();
+            break;
+    }
+}
+
+int64_t Choreographer::getFrameInterval() const {
+    return mLastVsyncEventData.frameInterval;
+}
+
+bool Choreographer::inCallback() const {
+    return mInCallback;
+}
+
+ChoreographerFrameCallbackDataImpl Choreographer::createFrameCallbackData(nsecs_t timestamp) const {
+    return {.frameTimeNanos = timestamp,
+            .vsyncEventData = mLastVsyncEventData,
+            .choreographer = this};
+}
+
+void Choreographer::registerStartTime() const {
+    std::scoped_lock _l(gChoreographers.lock);
+    for (VsyncEventData::FrameTimeline frameTimeline : mLastVsyncEventData.frameTimelines) {
+        while (gChoreographers.startTimes.size() >= kMaxStartTimes) {
+            gChoreographers.startTimes.erase(gChoreographers.startTimes.begin());
+        }
+        gChoreographers.startTimes[frameTimeline.vsyncId] = systemTime(SYSTEM_TIME_MONOTONIC);
+    }
+}
+
+void Choreographer::signalRefreshRateCallbacks(nsecs_t vsyncPeriod) {
+    std::lock_guard<std::mutex> _l(gChoreographers.lock);
+    gChoreographers.mLastKnownVsync.store(vsyncPeriod);
+    for (auto c : gChoreographers.ptrs) {
+        c->scheduleLatestConfigRequest();
+    }
+}
+
+int64_t Choreographer::getStartTimeNanosForVsyncId(AVsyncId vsyncId) {
+    std::scoped_lock _l(gChoreographers.lock);
+    const auto iter = gChoreographers.startTimes.find(vsyncId);
+    if (iter == gChoreographers.startTimes.end()) {
+        ALOGW("Start time was not found for vsync id: %" PRId64, vsyncId);
+        return 0;
+    }
+    return iter->second;
+}
+
+} // namespace android
\ No newline at end of file
diff --git a/libs/nativedisplay/include/nativedisplay/Choreographer.h b/libs/nativedisplay/include/nativedisplay/Choreographer.h
new file mode 100644
index 0000000..bb63f29
--- /dev/null
+++ b/libs/nativedisplay/include/nativedisplay/Choreographer.h
@@ -0,0 +1,138 @@
+/*
+ * Copyright 2022 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.
+ */
+
+#pragma once
+
+#include <gui/DisplayEventDispatcher.h>
+#include <private/android/choreographer.h>
+#include <utils/Looper.h>
+
+#include <mutex>
+#include <queue>
+#include <thread>
+
+namespace android {
+using gui::VsyncEventData;
+
+struct FrameCallback {
+    AChoreographer_frameCallback callback;
+    AChoreographer_frameCallback64 callback64;
+    AChoreographer_vsyncCallback vsyncCallback;
+    void* data;
+    nsecs_t dueTime;
+
+    inline bool operator<(const FrameCallback& rhs) const {
+        // Note that this is intentionally flipped because we want callbacks due sooner to be at
+        // the head of the queue
+        return dueTime > rhs.dueTime;
+    }
+};
+
+struct RefreshRateCallback {
+    AChoreographer_refreshRateCallback callback;
+    void* data;
+    bool firstCallbackFired = false;
+};
+
+class Choreographer;
+
+/**
+ * Implementation of AChoreographerFrameCallbackData.
+ */
+struct ChoreographerFrameCallbackDataImpl {
+    int64_t frameTimeNanos{0};
+
+    VsyncEventData vsyncEventData;
+
+    const Choreographer* choreographer;
+};
+
+class Choreographer : public DisplayEventDispatcher, public MessageHandler {
+public:
+    struct Context {
+        std::mutex lock;
+        std::vector<Choreographer*> ptrs GUARDED_BY(lock);
+        std::map<AVsyncId, int64_t> startTimes GUARDED_BY(lock);
+        bool registeredToDisplayManager GUARDED_BY(lock) = false;
+
+        std::atomic<nsecs_t> mLastKnownVsync = -1;
+    };
+    static Context gChoreographers;
+
+    explicit Choreographer(const sp<Looper>& looper) EXCLUDES(gChoreographers.lock);
+    void postFrameCallbackDelayed(AChoreographer_frameCallback cb,
+                                  AChoreographer_frameCallback64 cb64,
+                                  AChoreographer_vsyncCallback vsyncCallback, void* data,
+                                  nsecs_t delay);
+    void registerRefreshRateCallback(AChoreographer_refreshRateCallback cb, void* data)
+            EXCLUDES(gChoreographers.lock);
+    void unregisterRefreshRateCallback(AChoreographer_refreshRateCallback cb, void* data);
+    // Drains the queue of pending vsync periods and dispatches refresh rate
+    // updates to callbacks.
+    // The assumption is that this method is only called on a single
+    // processing thread, either by looper or by AChoreographer_handleEvents
+    void handleRefreshRateUpdates();
+    void scheduleLatestConfigRequest();
+
+    enum {
+        MSG_SCHEDULE_CALLBACKS = 0,
+        MSG_SCHEDULE_VSYNC = 1,
+        MSG_HANDLE_REFRESH_RATE_UPDATES = 2,
+    };
+    virtual void handleMessage(const Message& message) override;
+
+    static void initJVM(JNIEnv* env);
+    static Choreographer* getForThread();
+    static void signalRefreshRateCallbacks(nsecs_t vsyncPeriod) EXCLUDES(gChoreographers.lock);
+    static int64_t getStartTimeNanosForVsyncId(AVsyncId vsyncId) EXCLUDES(gChoreographers.lock);
+    virtual ~Choreographer() override EXCLUDES(gChoreographers.lock);
+    int64_t getFrameInterval() const;
+    bool inCallback() const;
+
+private:
+    Choreographer(const Choreographer&) = delete;
+
+    void dispatchVsync(nsecs_t timestamp, PhysicalDisplayId displayId, uint32_t count,
+                       VsyncEventData vsyncEventData) override;
+    void dispatchHotplug(nsecs_t timestamp, PhysicalDisplayId displayId, bool connected) override;
+    void dispatchModeChanged(nsecs_t timestamp, PhysicalDisplayId displayId, int32_t modeId,
+                             nsecs_t vsyncPeriod) override;
+    void dispatchNullEvent(nsecs_t, PhysicalDisplayId) override;
+    void dispatchFrameRateOverrides(nsecs_t timestamp, PhysicalDisplayId displayId,
+                                    std::vector<FrameRateOverride> overrides) override;
+
+    void scheduleCallbacks();
+
+    ChoreographerFrameCallbackDataImpl createFrameCallbackData(nsecs_t timestamp) const;
+    void registerStartTime() const;
+
+    std::mutex mLock;
+    // Protected by mLock
+    std::priority_queue<FrameCallback> mFrameCallbacks;
+    std::vector<RefreshRateCallback> mRefreshRateCallbacks;
+
+    nsecs_t mLatestVsyncPeriod = -1;
+    VsyncEventData mLastVsyncEventData;
+    bool mInCallback = false;
+
+    const sp<Looper> mLooper;
+    const std::thread::id mThreadId;
+
+    // Approximation of num_threads_using_choreographer * num_frames_of_history with leeway.
+    static constexpr size_t kMaxStartTimes = 250;
+};
+
+} // namespace android
\ No newline at end of file