Have the Surface class track the buffer age.

Have the Surface class track the buffer age, so that Surface::query()
can return the buffer age without having to use a binder call to
BufferQueueProducer::query().  The idea is for
BufferQueueProducer::dequeueBuffer() to return the value, which the
Surface class will cache for later use by Surface::query().

Bug: b/27903668
Test: Use systrace to no ensure query binder call after dequeueBuffer.
Change-Id: I106a7bd27461d381f0bd84df70d804de56a128ab

1 files changed, 7 insertions, 4 deletions

diff --git a/libs/gui/BufferQueueProducer.cpp b/libs/gui/BufferQueueProducer.cpp
index 3d94a029e5..3424012acf 100644
--- a/libs/gui/BufferQueueProducer.cpp
+++ b/libs/gui/BufferQueueProducer.cpp
@@ -347,10 +347,10 @@ status_t BufferQueueProducer::waitForFreeSlotThenRelock(FreeSlotCaller caller,
     return NO_ERROR;
 }
 
-status_t BufferQueueProducer::dequeueBuffer(int *outSlot,
-        sp<android::Fence> *outFence, uint32_t width, uint32_t height,
-        PixelFormat format, uint64_t usage,
-        FrameEventHistoryDelta* outTimestamps) {
+status_t BufferQueueProducer::dequeueBuffer(int* outSlot, sp<android::Fence>* outFence,
+                                            uint32_t width, uint32_t height, PixelFormat format,
+                                            uint64_t usage, uint64_t* outBufferAge,
+                                            FrameEventHistoryDelta* outTimestamps) {
     ATRACE_CALL();
     { // Autolock scope
         Mutex::Autolock lock(mCore->mMutex);
@@ -558,6 +558,9 @@ status_t BufferQueueProducer::dequeueBuffer(int *outSlot,
             mSlots[*outSlot].mFrameNumber,
             mSlots[*outSlot].mGraphicBuffer->handle, returnFlags);
 
+    if (outBufferAge) {
+        *outBufferAge = mCore->mBufferAge;
+    }
     addAndGetFrameTimestamps(nullptr, outTimestamps);
 
     return returnFlags;