status_t BufferQueue::acquireBuffer(BufferItem *buffer) {
ATRACE_CALL();
Mutex::Autolock _l(mMutex);
+
+ // Check that the consumer doesn't currently have the maximum number of
+ // buffers acquired. We allow the max buffer count to be exceeded by one
+ // buffer, so that the consumer can successfully set up the newly acquired
+ // buffer before releasing the old one.
+ int numAcquiredBuffers = 0;
+ for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
+ if (mSlots[i].mBufferState == BufferSlot::ACQUIRED) {
+ numAcquiredBuffers++;
+ }
+ }
+ if (numAcquiredBuffers >= mMaxAcquiredBufferCount+1) {
+ ST_LOGE("acquireBuffer: max acquired buffer count reached: %d (max=%d)",
+ numAcquiredBuffers, mMaxAcquiredBufferCount);
+ return INVALID_OPERATION;
+ }
+
// check if queue is empty
// In asynchronous mode the list is guaranteed to be one buffer
// deep, while in synchronous mode we use the oldest buffer.