Revert "libgui: Change BufferQueue to use free lists"
This reverts commit 8dddc990103b71137be2a6365a26b1ac36598e68.
Change-Id: I0b0fed9f1394c6f6ae812f6c562ead4473a8226e
diff --git a/libs/gui/BufferQueueProducer.cpp b/libs/gui/BufferQueueProducer.cpp
index b54641e..6452cdd 100644
--- a/libs/gui/BufferQueueProducer.cpp
+++ b/libs/gui/BufferQueueProducer.cpp
@@ -161,6 +161,8 @@
}
}
+ // Look for a free buffer to give to the client
+ *found = BufferQueueCore::INVALID_BUFFER_SLOT;
int dequeuedCount = 0;
int acquiredCount = 0;
for (int s = 0; s < maxBufferCount; ++s) {
@@ -171,6 +173,15 @@
case BufferSlot::ACQUIRED:
++acquiredCount;
break;
+ case BufferSlot::FREE:
+ // We return the oldest of the free buffers to avoid
+ // stalling the producer if possible, since the consumer
+ // may still have pending reads of in-flight buffers
+ if (*found == BufferQueueCore::INVALID_BUFFER_SLOT ||
+ mSlots[s].mFrameNumber < mSlots[*found].mFrameNumber) {
+ *found = s;
+ }
+ break;
default:
break;
}
@@ -203,8 +214,6 @@
}
}
- *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
@@ -214,16 +223,6 @@
if (tooManyBuffers) {
BQ_LOGV("%s: queue size is %zu, waiting", caller,
mCore->mQueue.size());
- } else {
- if (!mCore->mFreeBuffers.empty()) {
- auto slot = mCore->mFreeBuffers.begin();
- *found = *slot;
- mCore->mFreeBuffers.erase(slot);
- } else if (!mCore->mFreeSlots.empty()) {
- auto slot = mCore->mFreeSlots.begin();
- *found = *slot;
- mCore->mFreeSlots.erase(slot);
- }
}
// If no buffer is found, or if the queue has too many buffers
@@ -336,8 +335,6 @@
*outFence = mSlots[found].mFence;
mSlots[found].mEglFence = EGL_NO_SYNC_KHR;
mSlots[found].mFence = Fence::NO_FENCE;
-
- mCore->validateConsistencyLocked();
} // Autolock scope
if (returnFlags & BUFFER_NEEDS_REALLOCATION) {
@@ -358,6 +355,7 @@
return NO_INIT;
}
+ mSlots[*outSlot].mFrameNumber = UINT32_MAX;
mSlots[*outSlot].mGraphicBuffer = graphicBuffer;
} // Autolock scope
}
@@ -416,7 +414,6 @@
mCore->freeBufferLocked(slot);
mCore->mDequeueCondition.broadcast();
- mCore->validateConsistencyLocked();
return NO_ERROR;
}
@@ -441,19 +438,27 @@
return NO_INIT;
}
- if (mCore->mFreeBuffers.empty()) {
- return NO_MEMORY;
+ // Find the oldest valid slot
+ int found = BufferQueueCore::INVALID_BUFFER_SLOT;
+ for (int s = 0; s < BufferQueueDefs::NUM_BUFFER_SLOTS; ++s) {
+ if (mSlots[s].mBufferState == BufferSlot::FREE &&
+ mSlots[s].mGraphicBuffer != NULL) {
+ if (found == BufferQueueCore::INVALID_BUFFER_SLOT ||
+ mSlots[s].mFrameNumber < mSlots[found].mFrameNumber) {
+ found = s;
+ }
+ }
}
- int found = mCore->mFreeBuffers.front();
- mCore->mFreeBuffers.remove(found);
+ if (found == BufferQueueCore::INVALID_BUFFER_SLOT) {
+ return NO_MEMORY;
+ }
BQ_LOGV("detachNextBuffer detached slot %d", found);
*outBuffer = mSlots[found].mGraphicBuffer;
*outFence = mSlots[found].mFence;
mCore->freeBufferLocked(found);
- mCore->validateConsistencyLocked();
return NO_ERROR;
}
@@ -501,8 +506,6 @@
mSlots[*outSlot].mFence = Fence::NO_FENCE;
mSlots[*outSlot].mRequestBufferCalled = true;
- mCore->validateConsistencyLocked();
-
return returnFlags;
}
@@ -637,7 +640,9 @@
// mark it as freed
if (mCore->stillTracking(front)) {
mSlots[front->mSlot].mBufferState = BufferSlot::FREE;
- mCore->mFreeBuffers.push_front(front->mSlot);
+ // Reset the frame number of the freed buffer so that it is
+ // the first in line to be dequeued again
+ mSlots[front->mSlot].mFrameNumber = 0;
}
// Overwrite the droppable buffer with the incoming one
*front = item;
@@ -659,8 +664,6 @@
// Take a ticket for the callback functions
callbackTicket = mNextCallbackTicket++;
-
- mCore->validateConsistencyLocked();
} // Autolock scope
// Wait without lock held
@@ -721,11 +724,10 @@
return;
}
- mCore->mFreeBuffers.push_front(slot);
mSlots[slot].mBufferState = BufferSlot::FREE;
+ mSlots[slot].mFrameNumber = 0;
mSlots[slot].mFence = fence;
mCore->mDequeueCondition.broadcast();
- mCore->validateConsistencyLocked();
}
int BufferQueueProducer::query(int what, int *outValue) {
@@ -1007,19 +1009,13 @@
}
mCore->freeBufferLocked(slot); // Clean up the slot first
mSlots[slot].mGraphicBuffer = buffers[i];
+ mSlots[slot].mFrameNumber = 0;
mSlots[slot].mFence = Fence::NO_FENCE;
-
- // freeBufferLocked puts this slot on the free slots list. Since
- // we then attached a buffer, move the slot to free buffer list.
- mCore->mFreeSlots.erase(slot);
- mCore->mFreeBuffers.push_front(slot);
-
BQ_LOGV("allocateBuffers: allocated a new buffer in slot %d", slot);
}
mCore->mIsAllocating = false;
mCore->mIsAllocatingCondition.broadcast();
- mCore->validateConsistencyLocked();
} // Autolock scope
}
}