BufferQueue improvements and APIs changes
this is the first step of a series of improvements to
BufferQueue. A few things happen in this change:
- setSynchronousMode() goes away as well as the SynchronousModeAllowed flag
- BufferQueue now defaults to (what used to be) synchronous mode
- a new "controlled by app" flag is passed when creating consumers and producers
those flags are used to put the BufferQueue in a mode where it
will never block if both flags are set. This is achieved by:
- returning an error from dequeueBuffer() if it would block
- making sure a buffer is always available by replacing
the previous buffer with the new one in queueBuffer()
(note: this is similar to what asynchrnous mode used to be)
Note: in this change EGL's swap-interval 0 is broken; this will be
fixed in another change.
Change-Id: I691f9507d6e2e158287e3039f2a79a4d4434211d
diff --git a/libs/gui/BufferQueue.cpp b/libs/gui/BufferQueue.cpp
index 8d4b174..1e86a4f 100644
--- a/libs/gui/BufferQueue.cpp
+++ b/libs/gui/BufferQueue.cpp
@@ -63,15 +63,15 @@
}
}
-BufferQueue::BufferQueue(bool allowSynchronousMode,
- const sp<IGraphicBufferAlloc>& allocator) :
+BufferQueue::BufferQueue(const sp<IGraphicBufferAlloc>& allocator) :
mDefaultWidth(1),
mDefaultHeight(1),
mMaxAcquiredBufferCount(1),
mDefaultMaxBufferCount(2),
mOverrideMaxBufferCount(0),
- mSynchronousMode(false),
- mAllowSynchronousMode(allowSynchronousMode),
+ mConsumerControlledByApp(false),
+ mDequeueBufferCannotBlock(false),
+ mSynchronousMode(true),
mConnectedApi(NO_CONNECTED_API),
mAbandoned(false),
mFrameCounter(0),
@@ -109,11 +109,6 @@
return NO_ERROR;
}
-bool BufferQueue::isSynchronousMode() const {
- Mutex::Autolock lock(mMutex);
- return mSynchronousMode;
-}
-
void BufferQueue::setConsumerName(const String8& name) {
Mutex::Autolock lock(mMutex);
mConsumerName = name;
@@ -348,6 +343,10 @@
// the max buffer count to change.
tryAgain = found == INVALID_BUFFER_SLOT;
if (tryAgain) {
+ if (mDequeueBufferCannotBlock) {
+ ST_LOGE("dequeueBuffer: would block! returning an error instead.");
+ return WOULD_BLOCK;
+ }
mDequeueCondition.wait(mMutex);
}
}
@@ -441,38 +440,6 @@
return returnFlags;
}
-status_t BufferQueue::setSynchronousMode(bool enabled) {
- ATRACE_CALL();
- ST_LOGV("setSynchronousMode: enabled=%d", enabled);
- Mutex::Autolock lock(mMutex);
-
- if (mAbandoned) {
- ST_LOGE("setSynchronousMode: BufferQueue has been abandoned!");
- return NO_INIT;
- }
-
- status_t err = OK;
- if (!mAllowSynchronousMode && enabled)
- return err;
-
- if (!enabled) {
- // going to asynchronous mode, drain the queue
- err = drainQueueLocked();
- if (err != NO_ERROR)
- return err;
- }
-
- if (mSynchronousMode != enabled) {
- // - if we're going to asynchronous mode, the queue is guaranteed to be
- // empty here
- // - if the client set the number of buffers, we're guaranteed that
- // we have at least 3 (because we don't allow less)
- mSynchronousMode = enabled;
- mDequeueCondition.broadcast();
- }
- return err;
-}
-
status_t BufferQueue::queueBuffer(int buf,
const QueueBufferInput& input, QueueBufferOutput* output) {
ATRACE_CALL();
@@ -630,7 +597,7 @@
mDequeueCondition.broadcast();
}
-status_t BufferQueue::connect(int api, QueueBufferOutput* output) {
+status_t BufferQueue::connect(int api, bool producerControlledByApp, QueueBufferOutput* output) {
ATRACE_CALL();
ST_LOGV("connect: api=%d", api);
Mutex::Autolock lock(mMutex);
@@ -667,6 +634,8 @@
}
mBufferHasBeenQueued = false;
+ mDequeueBufferCannotBlock = mConsumerControlledByApp && producerControlledByApp;
+ mSynchronousMode = !mDequeueBufferCannotBlock;
return err;
}
@@ -950,7 +919,8 @@
return NO_ERROR;
}
-status_t BufferQueue::consumerConnect(const sp<ConsumerListener>& consumerListener) {
+status_t BufferQueue::consumerConnect(const sp<ConsumerListener>& consumerListener,
+ bool controlledByApp) {
ST_LOGV("consumerConnect");
Mutex::Autolock lock(mMutex);
@@ -964,6 +934,7 @@
}
mConsumerListener = consumerListener;
+ mConsumerControlledByApp = controlledByApp;
return NO_ERROR;
}