Revert "Revert "Bind to FBO when using GPU composition""

Hold for now while I propose a fix on top of this change.

This reverts commit 8d4f90aaadf9f3be77d258d2acd67b6186352811.

Reason for revert: Forward fixing

Bug: 117680609
Change-Id: I68a26ced146fa057de3aeb144cbfe2fa3c9842fe
Test: See If639ce2c6cd600eabb957d278815f80b413d92b3
diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index 5342bcf..d5b24ae 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -35,6 +35,8 @@
 #include <gui/Surface.h>
 #include <hardware/gralloc.h>
 #include <renderengine/RenderEngine.h>
+#include <sync/sync.h>
+#include <system/window.h>
 #include <ui/DebugUtils.h>
 #include <ui/DisplayInfo.h>
 #include <ui/PixelFormat.h>
@@ -221,6 +223,7 @@
         mDisplayToken(args.displayToken),
         mId(args.displayId),
         mNativeWindow(args.nativeWindow),
+        mGraphicBuffer(nullptr),
         mDisplaySurface(args.displaySurface),
         mSurface{std::move(args.renderSurface)},
         mDisplayInstallOrientation(args.displayInstallOrientation),
@@ -284,6 +287,10 @@
     mHdrCapabilities = HdrCapabilities(types, maxLuminance, maxAverageLuminance, minLuminance);
 
     ANativeWindow* const window = mNativeWindow.get();
+
+    int status = native_window_api_connect(mNativeWindow.get(), NATIVE_WINDOW_API_EGL);
+    ALOGE_IF(status != NO_ERROR, "Unable to connect BQ producer: %d", status);
+
     mDisplayWidth = ANativeWindow_getWidth(window);
     mDisplayHeight = ANativeWindow_getHeight(window);
 
@@ -321,7 +328,6 @@
 
 void DisplayDevice::flip() const
 {
-    mFlinger->getRenderEngine().checkErrors();
     mPageFlipCount++;
 }
 
@@ -356,9 +362,71 @@
     return mDisplaySurface->prepareFrame(compositionType);
 }
 
-void DisplayDevice::swapBuffers(HWComposer& hwc) const {
+sp<GraphicBuffer> DisplayDevice::dequeueBuffer() {
+    int fd;
+    ANativeWindowBuffer* buffer;
+
+    status_t res = mNativeWindow->dequeueBuffer(mNativeWindow.get(), &buffer, &fd);
+
+    if (res != NO_ERROR) {
+        ALOGE("ANativeWindow::dequeueBuffer failed for display [%s] with error: %d",
+              getDisplayName().c_str(), res);
+        // Return fast here as we can't do much more - any rendering we do
+        // now will just be wrong.
+        return mGraphicBuffer;
+    }
+
+    ALOGW_IF(mGraphicBuffer != nullptr, "Clobbering a non-null pointer to a buffer [%p].",
+             mGraphicBuffer->getNativeBuffer()->handle);
+    mGraphicBuffer = GraphicBuffer::from(buffer);
+
+    // Block until the buffer is ready
+    // TODO(alecmouri): it's perhaps more appropriate to block renderengine so
+    // that the gl driver can block instead.
+    if (fd >= 0) {
+        sync_wait(fd, -1);
+        close(fd);
+    }
+
+    return mGraphicBuffer;
+}
+
+void DisplayDevice::queueBuffer(HWComposer& hwc) {
     if (hwc.hasClientComposition(mId) || hwc.hasFlipClientTargetRequest(mId)) {
-        mSurface->swapBuffers();
+        // hasFlipClientTargetRequest could return true even if we haven't
+        // dequeued a buffer before. Try dequeueing one if we don't have a
+        // buffer ready.
+        if (mGraphicBuffer == nullptr) {
+            ALOGI("Attempting to queue a client composited buffer without one "
+                  "previously dequeued for display [%s]. Attempting to dequeue "
+                  "a scratch buffer now",
+                  mDisplayName.c_str());
+            // We shouldn't deadlock here, since mGraphicBuffer == nullptr only
+            // after a successful call to queueBuffer, or if dequeueBuffer has
+            // never been called.
+            dequeueBuffer();
+        }
+
+        if (mGraphicBuffer == nullptr) {
+            ALOGE("No buffer is ready for display [%s]", mDisplayName.c_str());
+        } else {
+            int fd = mBufferReady.release();
+
+            status_t res = mNativeWindow->queueBuffer(mNativeWindow.get(),
+                                                      mGraphicBuffer->getNativeBuffer(), fd);
+            if (res != NO_ERROR) {
+                ALOGE("Error when queueing buffer for display [%s]: %d", mDisplayName.c_str(), res);
+                // We risk blocking on dequeueBuffer if the primary display failed
+                // to queue up its buffer, so crash here.
+                if (isPrimary()) {
+                    LOG_ALWAYS_FATAL("ANativeWindow::queueBuffer failed with error: %d", res);
+                } else {
+                    mNativeWindow->cancelBuffer(mNativeWindow.get(),
+                                                mGraphicBuffer->getNativeBuffer(), fd);
+                }
+            }
+            mGraphicBuffer = nullptr;
+        }
     }
 
     status_t result = mDisplaySurface->advanceFrame();
@@ -367,7 +435,7 @@
     }
 }
 
-void DisplayDevice::onSwapBuffersCompleted() const {
+void DisplayDevice::onPresentDisplayCompleted() {
     mDisplaySurface->onFrameCommitted();
 }
 
@@ -384,6 +452,13 @@
     mFlinger->getRenderEngine().setViewportAndProjection(w, h, sourceCrop, ui::Transform::ROT_0);
 }
 
+void DisplayDevice::finishBuffer() {
+    mBufferReady = mFlinger->getRenderEngine().flush();
+    if (mBufferReady.get() < 0) {
+        mFlinger->getRenderEngine().finish();
+    }
+}
+
 const sp<Fence>& DisplayDevice::getClientTargetAcquireFence() const {
     return mDisplaySurface->getClientTargetAcquireFence();
 }