replicant-frameworks_native/include/gui/CpuConsumer.h
Eino-Ville Talvala 042ecee2ab CpuConsumer: Properly track acquired buffers
CpuConsumer cannot simply assume a slot's buffer is the same buffer
between acquire and release, and therefore it could be possible for
the same slot to get used for a second acquired buffer, if there's a
producer disconnect in between. This would cause a problem when the
first buffer is released by the consumer.

Instead, use an independent list of acquired buffers to properly track
their state.

Bug: 8291751
Change-Id: I0241ad8704e53d47318c7179b13daed8181b1fab
2013-03-05 15:25:06 -08:00

119 lines
4.0 KiB
C++

/*
* 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_CPUCONSUMER_H
#define ANDROID_GUI_CPUCONSUMER_H
#include <gui/ConsumerBase.h>
#include <ui/GraphicBuffer.h>
#include <utils/String8.h>
#include <utils/Vector.h>
#include <utils/threads.h>
#define ANDROID_GRAPHICS_CPUCONSUMER_JNI_ID "mCpuConsumer"
namespace android {
/**
* CpuConsumer is a BufferQueue consumer endpoint that allows direct CPU
* access to the underlying gralloc buffers provided by BufferQueue. Multiple
* buffers may be acquired by it at once, to be used concurrently by the
* CpuConsumer owner. Sets gralloc usage flags to be software-read-only.
* This queue is synchronous by default.
*/
class CpuConsumer : public ConsumerBase
{
public:
typedef ConsumerBase::FrameAvailableListener FrameAvailableListener;
struct LockedBuffer {
uint8_t *data;
uint32_t width;
uint32_t height;
PixelFormat format;
uint32_t stride;
Rect crop;
uint32_t transform;
uint32_t scalingMode;
int64_t timestamp;
uint64_t frameNumber;
};
// Create a new CPU consumer. The maxLockedBuffers parameter specifies
// how many buffers can be locked for user access at the same time.
CpuConsumer(uint32_t maxLockedBuffers, bool synchronousMode = true);
virtual ~CpuConsumer();
// set the name of the CpuConsumer that will be used to identify it in
// log messages.
void setName(const String8& name);
// Gets the next graphics buffer from the producer and locks it for CPU use,
// filling out the passed-in locked buffer structure with the native pointer
// and metadata. Returns BAD_VALUE if no new buffer is available, and
// INVALID_OPERATION if the maximum number of buffers is already locked.
//
// Only a fixed number of buffers can be locked at a time, determined by the
// construction-time maxLockedBuffers parameter. If INVALID_OPERATION is
// returned by lockNextBuffer, then old buffers must be returned to the queue
// by calling unlockBuffer before more buffers can be acquired.
status_t lockNextBuffer(LockedBuffer *nativeBuffer);
// Returns a locked buffer to the queue, allowing it to be reused. Since
// only a fixed number of buffers may be locked at a time, old buffers must
// be released by calling unlockBuffer to ensure new buffers can be acquired by
// lockNextBuffer.
status_t unlockBuffer(const LockedBuffer &nativeBuffer);
sp<IGraphicBufferProducer> getProducerInterface() const { return getBufferQueue(); }
private:
// Maximum number of buffers that can be locked at a time
uint32_t mMaxLockedBuffers;
status_t releaseAcquiredBufferLocked(int lockedIdx);
virtual void freeBufferLocked(int slotIndex);
// Tracking for buffers acquired by the user
struct AcquiredBuffer {
// Need to track the original mSlot index and the buffer itself because
// the mSlot entry may be freed/reused before the acquired buffer is
// released.
int mSlot;
sp<GraphicBuffer> mGraphicBuffer;
void *mBufferPointer;
AcquiredBuffer() :
mSlot(BufferQueue::INVALID_BUFFER_SLOT),
mBufferPointer(NULL) {
}
};
Vector<AcquiredBuffer> mAcquiredBuffers;
// Count of currently locked buffers
uint32_t mCurrentLockedBuffers;
};
} // namespace android
#endif // ANDROID_GUI_CPUCONSUMER_H