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, 4 insertions, 3 deletions

diff --git a/libs/gui/GLConsumer.cpp b/libs/gui/GLConsumer.cpp
index 6d29edc0c4..d12083fcb2 100644
--- a/libs/gui/GLConsumer.cpp
+++ b/libs/gui/GLConsumer.cpp
@@ -139,7 +139,7 @@ status_t GLConsumer::updateTexImage() {
     // Acquire the next buffer.
     // In asynchronous mode the list is guaranteed to be one buffer
     // deep, while in synchronous mode we use the oldest buffer.
-    err = acquireBufferLocked(&item);
+    err = acquireBufferLocked(&item, 0);
     if (err != NO_ERROR) {
         if (err == BufferQueue::NO_BUFFER_AVAILABLE) {
             // We always bind the texture even if we don't update its contents.
@@ -165,8 +165,9 @@ status_t GLConsumer::updateTexImage() {
     return bindTextureImageLocked();
 }
 
-status_t GLConsumer::acquireBufferLocked(BufferQueue::BufferItem *item) {
-    status_t err = ConsumerBase::acquireBufferLocked(item);
+status_t GLConsumer::acquireBufferLocked(BufferQueue::BufferItem *item,
+        nsecs_t presentWhen) {
+    status_t err = ConsumerBase::acquireBufferLocked(item, presentWhen);
     if (err != NO_ERROR) {
         return err;
     }