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Diffstat (limited to 'src/imports/nativemedia/BufferQueue.h')
| -rw-r--r-- | src/imports/nativemedia/BufferQueue.h | 490 |
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diff --git a/src/imports/nativemedia/BufferQueue.h b/src/imports/nativemedia/BufferQueue.h new file mode 100644 index 0000000..1c80d0c --- /dev/null +++ b/src/imports/nativemedia/BufferQueue.h @@ -0,0 +1,490 @@ +/* + * 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 <EGL/egl.h> +#include <EGL/eglext.h> + +#include <gui/IGraphicBufferAlloc.h> +#include <gui/ISurfaceTexture.h> + +#include <ui/GraphicBuffer.h> + +#include <utils/String8.h> +#include <utils/Vector.h> +#include <utils/threads.h> + +namespace android { +// ---------------------------------------------------------------------------- + +class BufferQueue : public BnSurfaceTexture { +public: + enum { MIN_UNDEQUEUED_BUFFERS = 2 }; + enum { NUM_BUFFER_SLOTS = 32 }; + enum { NO_CONNECTED_API = 0 }; + enum { INVALID_BUFFER_SLOT = -1 }; + enum { STALE_BUFFER_SLOT = 1, NO_BUFFER_AVAILABLE }; + + // ConsumerListener is the interface through which the BufferQueue notifies + // the consumer of events that the consumer may wish to react to. Because + // the consumer will generally have a mutex that is locked during calls from + // teh consumer to the BufferQueue, these calls from the BufferQueue to the + // consumer *MUST* be called only when the BufferQueue mutex is NOT locked. + struct ConsumerListener : public virtual RefBase { + // onFrameAvailable is called from queueBuffer each time an additional + // frame becomes available for consumption. This means that frames that + // are queued while in asynchronous mode only trigger the callback if no + // previous frames are pending. Frames queued while in synchronous mode + // always trigger the callback. + // + // This is called without any lock held and can be called concurrently + // by multiple threads. + virtual void onFrameAvailable() = 0; + + // onBuffersReleased is called to notify the buffer consumer that the + // BufferQueue has released its references to one or more GraphicBuffers + // contained in its slots. The buffer consumer should then call + // BufferQueue::getReleasedBuffers to retrieve the list of buffers + // + // This is called without any lock held and can be called concurrently + // by multiple threads. + virtual void onBuffersReleased() = 0; + }; + + // 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 BufferQueue::ConsumerListener { + public: + + ProxyConsumerListener(const wp<BufferQueue::ConsumerListener>& consumerListener); + virtual ~ProxyConsumerListener(); + virtual void onFrameAvailable(); + virtual void onBuffersReleased(); + + private: + + // mConsumerListener is a weak reference to the ConsumerListener. This is + // the raison d'etre of ProxyConsumerListener. + wp<BufferQueue::ConsumerListener> mConsumerListener; + }; + + + // BufferQueue manages a pool of gralloc memory slots to be used + // by producers and consumers. + // allowSynchronousMode specifies whether or not synchronous mode can be + // enabled. + // bufferCount sets the minimum number of undequeued buffers for this queue + BufferQueue( bool allowSynchronousMode = true, int bufferCount = MIN_UNDEQUEUED_BUFFERS); + virtual ~BufferQueue(); + + virtual int query(int what, int* value); + + // setBufferCount updates the number of available buffer slots. After + // calling this all buffer slots are both unallocated and owned by the + // BufferQueue object (i.e. they are not owned by the client). + virtual status_t setBufferCount(int bufferCount); + + virtual status_t requestBuffer(int slot, sp<GraphicBuffer>* buf); + + // dequeueBuffer gets the next buffer slot index for the client to use. If a + // buffer slot is available then that slot index is written to the location + // pointed to by the buf argument and a status of OK is returned. If no + // slot is available then a status of -EBUSY is returned and buf is + // unmodified. + // The width and height parameters must be no greater than the minimum of + // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). + // An error due to invalid dimensions might not be reported until + // updateTexImage() is called. + virtual status_t dequeueBuffer(int *buf, uint32_t width, uint32_t height, + uint32_t format, uint32_t usage); + + // queueBuffer returns a filled buffer to the BufferQueue. In addition, a + // timestamp must be provided for the buffer. The timestamp is in + // nanoseconds, and must be monotonically increasing. Its other semantics + // (zero point, etc) are client-dependent and should be documented by the + // client. + virtual status_t queueBuffer(int buf, + const QueueBufferInput& input, QueueBufferOutput* output); + + virtual void cancelBuffer(int buf); + + // setSynchronousMode set whether dequeueBuffer is synchronous or + // asynchronous. In synchronous mode, dequeueBuffer blocks until + // a buffer is available, the currently bound buffer can be dequeued and + // queued buffers will be retired in order. + // The default mode is asynchronous. + virtual status_t setSynchronousMode(bool enabled); + + // connect attempts to connect a producer client API to the BufferQueue. + // This must be called before any other ISurfaceTexture methods are called + // except for getAllocator. + // + // This method will fail if the connect was previously called on the + // BufferQueue and no corresponding disconnect call was made. + virtual status_t connect(int api, QueueBufferOutput* output); + + // disconnect attempts to disconnect a producer client API from the + // BufferQueue. Calling this method will cause any subsequent calls to other + // ISurfaceTexture methods to fail except for getAllocator and connect. + // Successfully calling connect after this will allow the other methods to + // succeed again. + // + // This method will fail if the the BufferQueue is not currently + // connected to the specified client API. + virtual status_t disconnect(int api); + + // dump our state in a String + virtual void dump(String8& result) const; + virtual void dump(String8& result, const char* prefix, char* buffer, size_t SIZE) const; + + // public facing structure for BufferSlot + struct BufferItem { + + BufferItem() + : + mTransform(0), + mScalingMode(NATIVE_WINDOW_SCALING_MODE_FREEZE), + mTimestamp(0), + mFrameNumber(0), + mBuf(INVALID_BUFFER_SLOT) { + mCrop.makeInvalid(); + } + // mGraphicBuffer points to the buffer allocated for this slot or is NULL + // if no buffer has been allocated. + sp<GraphicBuffer> mGraphicBuffer; + + // mCrop is the current crop rectangle for this buffer slot. + Rect mCrop; + + // mTransform is the current transform flags for this buffer slot. + uint32_t mTransform; + + // mScalingMode is the current scaling mode for this buffer slot. + uint32_t mScalingMode; + + // mTimestamp is the current timestamp for this buffer slot. This gets + // to set by queueBuffer each time this slot is queued. + int64_t mTimestamp; + + // mFrameNumber is the number of the queued frame for this slot. + uint64_t mFrameNumber; + + // mBuf is the slot index of this buffer + int mBuf; + }; + + // The following public functions is the consumer facing interface + + // acquireBuffer attempts to acquire ownership of the next pending buffer in + // the BufferQueue. If no buffer is pending then it returns -EINVAL. If a + // buffer is successfully acquired, the information about the buffer is + // returned in BufferItem. If the buffer returned had previously been + // acquired then the BufferItem::mGraphicBuffer field of buffer is set to + // NULL and it is assumed that the consumer still holds a reference to the + // buffer. + status_t acquireBuffer(BufferItem *buffer); + + // releaseBuffer releases a buffer slot from the consumer back to the + // BufferQueue pending a fence sync. + // + // Note that the dependencies on EGL will be removed once we switch to using + // the Android HW Sync HAL. + status_t releaseBuffer(int buf, EGLDisplay display, EGLSyncKHR fence); + + // consumerConnect connects a consumer to the BufferQueue. Only one + // consumer may be connected, and when that consumer disconnects the + // BufferQueue is placed into the "abandoned" state, causing most + // interactions with the BufferQueue by the producer to fail. + status_t consumerConnect(const sp<ConsumerListener>& consumer); + + // consumerDisconnect disconnects a consumer from the BufferQueue. All + // buffers will be freed and the BufferQueue is placed in the "abandoned" + // state, causing most interactions with the BufferQueue by the producer to + // fail. + status_t consumerDisconnect(); + + // getReleasedBuffers sets the value pointed to by slotMask to a bit mask + // indicating which buffer slots the have been released by the BufferQueue + // but have not yet been released by the consumer. + status_t getReleasedBuffers(uint32_t* slotMask); + + // setDefaultBufferSize is used to set the size of buffers returned by + // requestBuffers when a with and height of zero is requested. + status_t setDefaultBufferSize(uint32_t w, uint32_t h); + + // setBufferCountServer set the buffer count. If the client has requested + // a buffer count using setBufferCount, the server-buffer count will + // take effect once the client sets the count back to zero. + status_t setBufferCountServer(int bufferCount); + + // isSynchronousMode returns whether the SurfaceTexture is currently in + // synchronous mode. + bool isSynchronousMode() const; + + // setConsumerName sets the name used in logging + void setConsumerName(const String8& name); + + // setDefaultBufferFormat allows the BufferQueue to create + // GraphicBuffers of a defaultFormat if no format is specified + // in dequeueBuffer + status_t setDefaultBufferFormat(uint32_t defaultFormat); + + // setConsumerUsageBits will turn on additional usage bits for dequeueBuffer + status_t setConsumerUsageBits(uint32_t usage); + + // setTransformHint bakes in rotation to buffers so overlays can be used + status_t setTransformHint(uint32_t hint); + +private: + // freeBufferLocked frees the resources (both GraphicBuffer and EGLImage) + // for the given slot. + void freeBufferLocked(int index); + + // freeAllBuffersLocked frees the resources (both GraphicBuffer and + // EGLImage) for all slots. + void freeAllBuffersLocked(); + + // freeAllBuffersExceptHeadLocked frees the resources (both GraphicBuffer + // and EGLImage) for all slots except the head of mQueue + void freeAllBuffersExceptHeadLocked(); + + // drainQueueLocked drains the buffer queue if we're in synchronous mode + // returns immediately otherwise. It returns NO_INIT if the BufferQueue + // became abandoned or disconnected during this call. + status_t drainQueueLocked(); + + // drainQueueAndFreeBuffersLocked drains the buffer queue if we're in + // synchronous mode and free all buffers. In asynchronous mode, all buffers + // are freed except the current buffer. + status_t drainQueueAndFreeBuffersLocked(); + + status_t setBufferCountServerLocked(int bufferCount); + + struct BufferSlot { + + BufferSlot() + : mEglDisplay(EGL_NO_DISPLAY), + mBufferState(BufferSlot::FREE), + mRequestBufferCalled(false), + mTransform(0), + mScalingMode(NATIVE_WINDOW_SCALING_MODE_FREEZE), + mTimestamp(0), + mFrameNumber(0), + mFence(EGL_NO_SYNC_KHR), + mAcquireCalled(false), + mNeedsCleanupOnRelease(false) { + mCrop.makeInvalid(); + } + + // mGraphicBuffer points to the buffer allocated for this slot or is NULL + // if no buffer has been allocated. + sp<GraphicBuffer> mGraphicBuffer; + + // mEglDisplay is the EGLDisplay used to create mEglImage. + EGLDisplay mEglDisplay; + + // BufferState represents the different states in which a buffer slot + // can be. + enum BufferState { + // FREE indicates that the buffer is not currently being used and + // will not be used in the future until it gets dequeued and + // subsequently queued by the client. + // aka "owned by BufferQueue, ready to be dequeued" + FREE = 0, + + // DEQUEUED indicates that the buffer has been dequeued by the + // client, but has not yet been queued or canceled. The buffer is + // considered 'owned' by the client, and the server should not use + // it for anything. + // + // Note that when in synchronous-mode (mSynchronousMode == true), + // the buffer that's currently attached to the texture may be + // dequeued by the client. That means that the current buffer can + // be in either the DEQUEUED or QUEUED state. In asynchronous mode, + // however, the current buffer is always in the QUEUED state. + // aka "owned by producer, ready to be queued" + DEQUEUED = 1, + + // QUEUED indicates that the buffer has been queued by the client, + // and has not since been made available for the client to dequeue. + // Attaching the buffer to the texture does NOT transition the + // buffer away from the QUEUED state. However, in Synchronous mode + // the current buffer may be dequeued by the client under some + // circumstances. See the note about the current buffer in the + // documentation for DEQUEUED. + // aka "owned by BufferQueue, ready to be acquired" + QUEUED = 2, + + // aka "owned by consumer, ready to be released" + ACQUIRED = 3 + }; + + // mBufferState is the current state of this buffer slot. + BufferState mBufferState; + + // mRequestBufferCalled is used for validating that the client did + // call requestBuffer() when told to do so. Technically this is not + // needed but useful for debugging and catching client bugs. + bool mRequestBufferCalled; + + // mCrop is the current crop rectangle for this buffer slot. + Rect mCrop; + + // mTransform is the current transform flags for this buffer slot. + uint32_t mTransform; + + // mScalingMode is the current scaling mode for this buffer slot. + uint32_t mScalingMode; + + // mTimestamp is the current timestamp for this buffer slot. This gets + // to set by queueBuffer each time this slot is queued. + int64_t mTimestamp; + + // mFrameNumber is the number of the queued frame for this slot. + uint64_t mFrameNumber; + + // mFence is the EGL sync object that must signal before the buffer + // associated with this buffer slot may be dequeued. It is initialized + // to EGL_NO_SYNC_KHR when the buffer is created and (optionally, based + // on a compile-time option) set to a new sync object in updateTexImage. + EGLSyncKHR mFence; + + // Indicates whether this buffer has been seen by a consumer yet + bool mAcquireCalled; + + // Indicates whether this buffer needs to be cleaned up by consumer + bool mNeedsCleanupOnRelease; + }; + + // mSlots is the array of buffer slots that must be mirrored on the client + // side. This allows buffer ownership to be transferred between the client + // and server without sending a GraphicBuffer over binder. The entire array + // is initialized to NULL at construction time, and buffers are allocated + // for a slot when requestBuffer is called with that slot's index. + BufferSlot mSlots[NUM_BUFFER_SLOTS]; + + // mDefaultWidth holds the default width of allocated buffers. It is used + // in requestBuffers() if a width and height of zero is specified. + uint32_t mDefaultWidth; + + // mDefaultHeight holds the default height of allocated buffers. It is used + // in requestBuffers() if a width and height of zero is specified. + uint32_t mDefaultHeight; + + // mPixelFormat holds the pixel format of allocated buffers. It is used + // in requestBuffers() if a format of zero is specified. + uint32_t mPixelFormat; + + // mMinUndequeuedBuffers is a constraint on the number of buffers + // not dequeued at any time + int mMinUndequeuedBuffers; + + // mMinAsyncBufferSlots is a constraint on the minimum mBufferCount + // when this BufferQueue is in asynchronous mode + int mMinAsyncBufferSlots; + + // mMinSyncBufferSlots is a constraint on the minimum mBufferCount + // when this BufferQueue is in synchronous mode + int mMinSyncBufferSlots; + + // mBufferCount is the number of buffer slots that the client and server + // must maintain. It defaults to MIN_ASYNC_BUFFER_SLOTS and can be changed + // by calling setBufferCount or setBufferCountServer + int mBufferCount; + + // mClientBufferCount is the number of buffer slots requested by the client. + // The default is zero, which means the client doesn't care how many buffers + // there is. + int mClientBufferCount; + + // mServerBufferCount buffer count requested by the server-side + int mServerBufferCount; + + // mGraphicBufferAlloc is the connection to SurfaceFlinger that is used to + // allocate new GraphicBuffer objects. + sp<IGraphicBufferAlloc> mGraphicBufferAlloc; + + // mConsumerListener is used to notify the connected consumer of + // asynchronous events that it may wish to react to. It is initially set + // to NULL and is written by consumerConnect and consumerDisconnect. + sp<ConsumerListener> mConsumerListener; + + // mSynchronousMode whether we're in synchronous mode or not + bool mSynchronousMode; + + // mAllowSynchronousMode whether we allow synchronous mode or not + const bool mAllowSynchronousMode; + + // mConnectedApi indicates the API that is currently connected to this + // BufferQueue. It defaults to NO_CONNECTED_API (= 0), and gets updated + // by the connect and disconnect methods. + int mConnectedApi; + + // mDequeueCondition condition used for dequeueBuffer in synchronous mode + mutable Condition mDequeueCondition; + + // mQueue is a FIFO of queued buffers used in synchronous mode + typedef Vector<int> Fifo; + Fifo mQueue; + + // mAbandoned indicates that the BufferQueue will no longer be used to + // consume images buffers pushed to it using the ISurfaceTexture interface. + // It is initialized to false, and set to true in the abandon method. A + // BufferQueue that has been abandoned will return the NO_INIT error from + // all ISurfaceTexture methods capable of returning an error. + bool mAbandoned; + + // mName is a string used to identify the BufferQueue in log messages. + // It is set by the setName method. + String8 mConsumerName; + + // mMutex is the mutex used to prevent concurrent access to the member + // variables of BufferQueue objects. It must be locked whenever the + // member variables are accessed. + mutable Mutex mMutex; + + // mFrameCounter is the free running counter, incremented for every buffer queued + // with the surface Texture. + uint64_t mFrameCounter; + + // mBufferHasBeenQueued is true once a buffer has been queued. It is reset + // by changing the buffer count. + bool mBufferHasBeenQueued; + + // mDefaultBufferFormat can be set so it will override + // the buffer format when it isn't specified in dequeueBuffer + uint32_t mDefaultBufferFormat; + + // mConsumerUsageBits contains flags the consumer wants for GraphicBuffers + uint32_t mConsumerUsageBits; + + // mTransformHint is used to optimize for screen rotations + uint32_t mTransformHint; +}; + +// ---------------------------------------------------------------------------- +}; // namespace android + +#endif // ANDROID_GUI_BUFFERQUEUE_H |