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/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_GUI_BUFFERQUEUE_H
#define ANDROID_GUI_BUFFERQUEUE_H
#include <gui/BufferItem.h>
#include <gui/BufferQueueDefs.h>
#include <gui/IGraphicBufferConsumer.h>
#include <gui/IGraphicBufferProducer.h>
#include <gui/IConsumerListener.h>
// These are only required to keep other parts of the framework with incomplete
// dependencies building successfully
#include <gui/IGraphicBufferAlloc.h>
namespace android {
class BufferQueue {
public:
// BufferQueue will keep track of at most this value of buffers.
// Attempts at runtime to increase the number of buffers past this will fail.
enum { NUM_BUFFER_SLOTS = BufferQueueDefs::NUM_BUFFER_SLOTS };
// Used as a placeholder slot# when the value isn't pointing to an existing buffer.
enum { INVALID_BUFFER_SLOT = BufferItem::INVALID_BUFFER_SLOT };
// Alias to <IGraphicBufferConsumer.h> -- please scope from there in future code!
enum {
NO_BUFFER_AVAILABLE = IGraphicBufferConsumer::NO_BUFFER_AVAILABLE,
PRESENT_LATER = IGraphicBufferConsumer::PRESENT_LATER,
};
// When in async mode we reserve two slots in order to guarantee that the
// producer and consumer can run asynchronously.
enum { MAX_MAX_ACQUIRED_BUFFERS = NUM_BUFFER_SLOTS - 2 };
// for backward source compatibility
typedef ::android::ConsumerListener ConsumerListener;
// ProxyConsumerListener is a ConsumerListener implementation that keeps a weak
// reference to the actual consumer object. It forwards all calls to that
// consumer object so long as it exists.
//
// This class exists to avoid having a circular reference between the
// BufferQueue object and the consumer object. The reason this can't be a weak
// reference in the BufferQueue class is because we're planning to expose the
// consumer side of a BufferQueue as a binder interface, which doesn't support
// weak references.
class ProxyConsumerListener : public BnConsumerListener {
public:
ProxyConsumerListener(const wp<ConsumerListener>& consumerListener);
virtual ~ProxyConsumerListener();
virtual void onFrameAvailable(const BufferItem& item) override;
virtual void onFrameReplaced(const BufferItem& item) override;
virtual void onBuffersReleased() override;
virtual void onSidebandStreamChanged() override;
private:
// mConsumerListener is a weak reference to the IConsumerListener. This is
// the raison d'etre of ProxyConsumerListener.
wp<ConsumerListener> mConsumerListener;
};
// BufferQueue manages a pool of gralloc memory slots to be used by
// producers and consumers. allocator is used to allocate all the
// needed gralloc buffers.
static void createBufferQueue(sp<IGraphicBufferProducer>* outProducer,
sp<IGraphicBufferConsumer>* outConsumer,
const sp<IGraphicBufferAlloc>& allocator = NULL);
private:
BufferQueue(); // Create through createBufferQueue
};
// ----------------------------------------------------------------------------
}; // namespace android
#endif // ANDROID_GUI_BUFFERQUEUE_H