BufferQueue: Guard against unbounded queue growth
Adds logic to dequeueBuffer that blocks if there are currently too
many buffers in the queue. This prevents unbounded growth around
times where the slots are cleared but the queue is not (e.g.,
during rapid connect/disconnect or setBufferCount activity). This
replaces the fix from ag/377958 in a more general way.
Bug: 11293214
Change-Id: Ieb7adfcd076ff7ffe3d4d369397b2c29cf5099c3
diff --git a/libs/gui/BufferQueueConsumer.cpp b/libs/gui/BufferQueueConsumer.cpp
index 995ed5e..872eae6 100644
--- a/libs/gui/BufferQueueConsumer.cpp
+++ b/libs/gui/BufferQueueConsumer.cpp
@@ -160,8 +160,10 @@
}
mCore->mQueue.erase(front);
- // TODO: Should this call be after we free a slot while dropping buffers?
- // Simply acquiring the next buffer doesn't enable a producer to dequeue.
+
+ // We might have freed a slot while dropping old buffers, or the producer
+ // may be blocked waiting for the number of buffers in the queue to
+ // decrease.
mCore->mDequeueCondition.broadcast();
ATRACE_INT(mCore->mConsumerName.string(), mCore->mQueue.size());