Merge "graphics: discard stale data from message queue" into oc-mr1-dev
am: 710b7085f9
Change-Id: I2a2e69edf9e822b4bd44344163f79b7d036d95c3
diff --git a/graphics/composer/2.1/default/IComposerCommandBuffer.h b/graphics/composer/2.1/default/IComposerCommandBuffer.h
index 9ee5f4f..058709c 100644
--- a/graphics/composer/2.1/default/IComposerCommandBuffer.h
+++ b/graphics/composer/2.1/default/IComposerCommandBuffer.h
@@ -92,6 +92,23 @@
bool writeQueue(bool* outQueueChanged, uint32_t* outCommandLength,
hidl_vec<hidl_handle>* outCommandHandles)
{
+ // After data are written to the queue, it may not be read by the
+ // remote reader when
+ //
+ // - the writer does not send them (because of other errors)
+ // - the hwbinder transaction fails
+ // - the reader does not read them (because of other errors)
+ //
+ // Discard the stale data here.
+ size_t staleDataSize = mQueue ? mQueue->availableToRead() : 0;
+ if (staleDataSize > 0) {
+ ALOGW("discarding stale data from message queue");
+ CommandQueueType::MemTransaction tx;
+ if (mQueue->beginRead(staleDataSize, &tx)) {
+ mQueue->commitRead(staleDataSize);
+ }
+ }
+
// write data to queue, optionally resizing it
if (mQueue && (mDataMaxSize <= mQueue->getQuantumCount())) {
if (!mQueue->write(mData.get(), mDataWritten)) {