/* * 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 namespace android { // ---------------------------------------------------------------------------- class BufferQueue : public BnSurfaceTexture { public: enum { MIN_UNDEQUEUED_BUFFERS = 2 }; enum { MIN_ASYNC_BUFFER_SLOTS = MIN_UNDEQUEUED_BUFFERS + 1, MIN_SYNC_BUFFER_SLOTS = MIN_UNDEQUEUED_BUFFERS }; enum { NUM_BUFFER_SLOTS = 32 }; enum { NO_CONNECTED_API = 0 }; struct FrameAvailableListener : 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; }; // 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. BufferQueue(bool allowSynchronousMode = true); virtual ~BufferQueue(); // 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, uint32_t* outWidth, uint32_t* outHeight, uint32_t* outTransform); virtual void cancelBuffer(int buf); virtual status_t setCrop(const Rect& reg); virtual status_t setTransform(uint32_t transform); virtual status_t setScalingMode(int mode); // 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); protected: // 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); enum { INVALID_BUFFER_SLOT = -1 }; struct BufferSlot { BufferSlot() : mEglImage(EGL_NO_IMAGE_KHR), 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) { mCrop.makeInvalid(); } // mGraphicBuffer points to the buffer allocated for this slot or is NULL // if no buffer has been allocated. sp mGraphicBuffer; // mEglImage is the EGLImage created from mGraphicBuffer. EGLImageKHR mEglImage; // 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. 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. 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. QUEUED = 2, }; // 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. This gets // set to mNextCrop each time queueBuffer gets called for this buffer. Rect mCrop; // mTransform is the current transform flags for this buffer slot. This // gets set to mNextTransform each time queueBuffer gets called for this // slot. uint32_t mTransform; // mScalingMode is the current scaling mode for this buffer slot. This // gets set to mNextScalingMode each time queueBuffer gets called for // this 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; }; // 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; // 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; // mCurrentTexture is the buffer slot index of the buffer that is currently // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, // indicating that no buffer slot is currently bound to the texture. Note, // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean // that no buffer is bound to the texture. A call to setBufferCount will // reset mCurrentTexture to INVALID_BUFFER_SLOT. int mCurrentTexture; // mNextCrop is the crop rectangle that will be used for the next buffer // that gets queued. It is set by calling setCrop. Rect mNextCrop; // mNextTransform is the transform identifier that will be used for the next // buffer that gets queued. It is set by calling setTransform. uint32_t mNextTransform; // mNextScalingMode is the scaling mode that will be used for the next // buffers that get queued. It is set by calling setScalingMode. int mNextScalingMode; // mGraphicBufferAlloc is the connection to SurfaceFlinger that is used to // allocate new GraphicBuffer objects. sp mGraphicBufferAlloc; // mFrameAvailableListener is the listener object that will be called when a // new frame becomes available. If it is not NULL it will be called from // queueBuffer. sp mFrameAvailableListener; // 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 mName; // 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; }; // ---------------------------------------------------------------------------- }; // namespace android #endif // ANDROID_GUI_BUFFERQUEUE_H