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Merge "BufferQueue: Guard against unbounded queue growth"

This commit is contained in:
Dan Stoza 2014-04-21 21:40:33 +00:00 committed by Android (Google) Code Review
parent 1034cfc778 ae3c368233
commit 4cbf3c5344
2 changed files with 35 additions and 37 deletions
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6
libs/gui/BufferQueueConsumer.cpp
View File

@ -160,8 +160,10 @@ status_t BufferQueueConsumer::acquireBuffer(BufferItem* outBuffer,
}
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());

66
libs/gui/BufferQueueProducer.cpp
View File

@ -205,9 +205,21 @@ status_t BufferQueueProducer::waitForFreeSlotThenRelock(const char* caller,
}
}
// If no buffer is found, wait for a buffer to be released or for
// the max buffer count to change
tryAgain = (*found == BufferQueueCore::INVALID_BUFFER_SLOT);
// If we disconnect and reconnect quickly, we can be in a state where
// our slots are empty but we have many buffers in the queue. This can
// cause us to run out of memory if we outrun the consumer. Wait here if
// it looks like we have too many buffers queued up.
bool tooManyBuffers = mCore->mQueue.size() > maxBufferCount;
if (tooManyBuffers) {
BQ_LOGV("%s: queue size is %d, waiting", caller,
mCore->mQueue.size());
}
// If no buffer is found, or if the queue has too many buffers
// outstanding, wait for a buffer to be acquired or released, or for the
// max buffer count to change.
tryAgain = (*found == BufferQueueCore::INVALID_BUFFER_SLOT) ||
tooManyBuffers;
if (tryAgain) {
// Return an error if we're in non-blocking mode (producer and
// consumer are controlled by the application).
@ -707,41 +719,25 @@ status_t BufferQueueProducer::connect(const sp<IProducerListener>& listener,
BQ_LOGV("connect(P): api=%d producerControlledByApp=%s", api,
producerControlledByApp ? "true" : "false");
// If we disconnect and reconnect quickly, we can be in a state where our
// slots are empty but we have many buffers in the queue. This can cause us
// to run out of memory if we outrun the consumer. Wait here if it looks
// like we have too many buffers queued up.
while (true) {
if (mCore->mIsAbandoned) {
BQ_LOGE("connect(P): BufferQueue has been abandoned");
return NO_INIT;
}
if (mCore->mIsAbandoned) {
BQ_LOGE("connect(P): BufferQueue has been abandoned");
return NO_INIT;
}
if (mCore->mConsumerListener == NULL) {
BQ_LOGE("connect(P): BufferQueue has no consumer");
return NO_INIT;
}
if (mCore->mConsumerListener == NULL) {
BQ_LOGE("connect(P): BufferQueue has no consumer");
return NO_INIT;
}
if (output == NULL) {
BQ_LOGE("connect(P): output was NULL");
return BAD_VALUE;
}
if (output == NULL) {
BQ_LOGE("connect(P): output was NULL");
return BAD_VALUE;
}
if (mCore->mConnectedApi != BufferQueueCore::NO_CONNECTED_API) {
BQ_LOGE("connect(P): already connected (cur=%d req=%d)",
mCore->mConnectedApi, api);
return BAD_VALUE;
}
size_t maxBufferCount = mCore->getMaxBufferCountLocked(false);
if (mCore->mQueue.size() <= maxBufferCount) {
// The queue size seems small enough to proceed
// TODO: Make this bound tighter?
break;
}
BQ_LOGV("connect(P): queue size is %d, waiting", mCore->mQueue.size());
mCore->mDequeueCondition.wait(mCore->mMutex);
if (mCore->mConnectedApi != BufferQueueCore::NO_CONNECTED_API) {
BQ_LOGE("connect(P): already connected (cur=%d req=%d)",
mCore->mConnectedApi, api);
return BAD_VALUE;
}
int status = NO_ERROR;