Pay attention to buffer timestamps

When acquiring a buffer, SurfaceFlinger now computes the expected
presentation time and passes it to the BufferQueue acquireBuffer()
method.  If it's not yet time to display the buffer, acquireBuffer()
returns PRESENT_LATER instead of a buffer.

The current implementation of the expected-present-time computation
uses approximations and guesswork.

Bug 7900302

Change-Id: If9345611c5983a11a811935aaf27d6388a5036f1

1 files changed, 3 insertions, 2 deletions

diff --git a/libs/gui/ConsumerBase.cpp b/libs/gui/ConsumerBase.cpp
index fd9d15365b..deb2646693 100644
--- a/libs/gui/ConsumerBase.cpp
+++ b/libs/gui/ConsumerBase.cpp
@@ -182,8 +182,9 @@ void ConsumerBase::dumpLocked(String8& result, const char* prefix) const {
     }
 }
 
-status_t ConsumerBase::acquireBufferLocked(BufferQueue::BufferItem *item) {
-    status_t err = mBufferQueue->acquireBuffer(item);
+status_t ConsumerBase::acquireBufferLocked(BufferQueue::BufferItem *item,
+        nsecs_t presentWhen) {
+    status_t err = mBufferQueue->acquireBuffer(item, presentWhen);
     if (err != NO_ERROR) {
         return err;
     }