/* * 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 #include #include #include #include #include #include #include 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 }; // 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& 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 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* 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, int64_t timestamp, const Rect& crop, int scalingMode, uint32_t transform, uint32_t* outWidth, uint32_t* outHeight, uint32_t* outTransform); 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, uint32_t* outWidth, uint32_t* outHeight, uint32_t* outTransform); // 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 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; // buf 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& 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 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 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 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 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