|  | /* | 
|  | * 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/IGraphicBufferProducer.h> | 
|  |  | 
|  | #include <ui/Fence.h> | 
|  | #include <ui/GraphicBuffer.h> | 
|  |  | 
|  | #include <utils/String8.h> | 
|  | #include <utils/Vector.h> | 
|  | #include <utils/threads.h> | 
|  |  | 
|  | namespace android { | 
|  | // ---------------------------------------------------------------------------- | 
|  |  | 
|  | class BufferQueue : public BnGraphicBufferProducer { | 
|  | 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 }; | 
|  |  | 
|  | // 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 }; | 
|  |  | 
|  | // 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 | 
|  | // the 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 by the producer. allocator is used to | 
|  | // allocate all the needed gralloc buffers. | 
|  | BufferQueue(bool allowSynchronousMode = true, | 
|  | const sp<IGraphicBufferAlloc>& allocator = NULL); | 
|  | virtual ~BufferQueue(); | 
|  |  | 
|  | // Query native window attributes.  The "what" values are enumerated in | 
|  | // window.h (e.g. NATIVE_WINDOW_FORMAT). | 
|  | virtual int query(int what, int* value); | 
|  |  | 
|  | // setBufferCount updates the number of available buffer slots.  If this | 
|  | // method succeeds, buffer slots will be both unallocated and owned by | 
|  | // the BufferQueue object (i.e. they are not owned by the producer or | 
|  | // consumer). | 
|  | // | 
|  | // This will fail if the producer has dequeued any buffers, or if | 
|  | // bufferCount is invalid.  bufferCount must generally be a value | 
|  | // between the minimum undequeued buffer count and NUM_BUFFER_SLOTS | 
|  | // (inclusive).  It may also be set to zero (the default) to indicate | 
|  | // that the producer does not wish to set a value.  The minimum value | 
|  | // can be obtained by calling query(NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS, | 
|  | // ...). | 
|  | // | 
|  | // This may only be called by the producer.  The consumer will be told | 
|  | // to discard buffers through the onBuffersReleased callback. | 
|  | virtual status_t setBufferCount(int bufferCount); | 
|  |  | 
|  | // requestBuffer returns the GraphicBuffer for slot N. | 
|  | // | 
|  | // In normal operation, this is called the first time slot N is returned | 
|  | // by dequeueBuffer.  It must be called again if dequeueBuffer returns | 
|  | // flags indicating that previously-returned buffers are no longer valid. | 
|  | virtual status_t requestBuffer(int slot, sp<GraphicBuffer>* buf); | 
|  |  | 
|  | // dequeueBuffer gets the next buffer slot index for the producer 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 fence parameter will be updated to hold the fence associated with | 
|  | // the buffer. The contents of the buffer must not be overwritten until the | 
|  | // fence signals. If the fence is Fence::NO_FENCE, the buffer may be | 
|  | // written immediately. | 
|  | // | 
|  | // 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.  If width and height are both zero, the | 
|  | // default values specified by setDefaultBufferSize() are used instead. | 
|  | // | 
|  | // The pixel formats are enumerated in graphics.h, e.g. | 
|  | // HAL_PIXEL_FORMAT_RGBA_8888.  If the format is 0, the default format | 
|  | // will be used. | 
|  | // | 
|  | // The usage argument specifies gralloc buffer usage flags.  The values | 
|  | // are enumerated in gralloc.h, e.g. GRALLOC_USAGE_HW_RENDER.  These | 
|  | // will be merged with the usage flags specified by setConsumerUsageBits. | 
|  | // | 
|  | // The return value may be a negative error value or a non-negative | 
|  | // collection of flags.  If the flags are set, the return values are | 
|  | // valid, but additional actions must be performed. | 
|  | // | 
|  | // If IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION is set, the | 
|  | // producer must discard cached GraphicBuffer references for the slot | 
|  | // returned in buf. | 
|  | // If IGraphicBufferProducer::RELEASE_ALL_BUFFERS is set, the producer | 
|  | // must discard cached GraphicBuffer references for all slots. | 
|  | // | 
|  | // In both cases, the producer will need to call requestBuffer to get a | 
|  | // GraphicBuffer handle for the returned slot. | 
|  | virtual status_t dequeueBuffer(int *buf, sp<Fence>* fence, | 
|  | uint32_t width, uint32_t height, uint32_t format, uint32_t usage); | 
|  |  | 
|  | // queueBuffer returns a filled buffer to the BufferQueue. | 
|  | // | 
|  | // Additional data is provided in the QueueBufferInput struct.  Notably, | 
|  | // 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 producer-specific and should be documented by the | 
|  | // producer. | 
|  | // | 
|  | // The caller may provide a fence that signals when all rendering | 
|  | // operations have completed.  Alternatively, NO_FENCE may be used, | 
|  | // indicating that the buffer is ready immediately. | 
|  | // | 
|  | // Some values are returned in the output struct: the current settings | 
|  | // for default width and height, the current transform hint, and the | 
|  | // number of queued buffers. | 
|  | virtual status_t queueBuffer(int buf, | 
|  | const QueueBufferInput& input, QueueBufferOutput* output); | 
|  |  | 
|  | // cancelBuffer returns a dequeued buffer to the BufferQueue, but doesn't | 
|  | // queue it for use by the consumer. | 
|  | // | 
|  | // The buffer will not be overwritten until the fence signals.  The fence | 
|  | // will usually be the one obtained from dequeueBuffer. | 
|  | virtual void cancelBuffer(int buf, const sp<Fence>& fence); | 
|  |  | 
|  | // setSynchronousMode sets 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 acquired in order.  In asynchronous mode, | 
|  | // a queued buffer may be replaced by a subsequently queued buffer. | 
|  | // | 
|  | // The default mode is asynchronous. | 
|  | virtual status_t setSynchronousMode(bool enabled); | 
|  |  | 
|  | // connect attempts to connect a producer API to the BufferQueue.  This | 
|  | // must be called before any other IGraphicBufferProducer methods are | 
|  | // called except for getAllocator.  A consumer must already be connected. | 
|  | // | 
|  | // This method will fail if connect was previously called on the | 
|  | // BufferQueue and no corresponding disconnect call was made (i.e. if | 
|  | // it's still connected to a producer). | 
|  | // | 
|  | // APIs are enumerated in window.h (e.g. NATIVE_WINDOW_API_CPU). | 
|  | virtual status_t connect(int api, QueueBufferOutput* output); | 
|  |  | 
|  | // disconnect attempts to disconnect a producer API from the BufferQueue. | 
|  | // Calling this method will cause any subsequent calls to other | 
|  | // IGraphicBufferProducer 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 producer 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 the buffer in this slot has been acquired in the past (see | 
|  | // BufferSlot.mAcquireCalled). | 
|  | 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; | 
|  |  | 
|  | // mFence is a fence that will signal when the buffer is idle. | 
|  | sp<Fence> mFence; | 
|  | }; | 
|  |  | 
|  | // The following public functions are 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.  This may be done while the buffer's contents are still | 
|  | // being accessed.  The fence will signal when the buffer is no longer | 
|  | // in use. | 
|  | // | 
|  | // If releaseBuffer returns STALE_BUFFER_SLOT, then the consumer must free | 
|  | // any references to the just-released buffer that it might have, as if it | 
|  | // had received a onBuffersReleased() call with a mask set for the released | 
|  | // buffer. | 
|  | // | 
|  | // 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, | 
|  | const sp<Fence>& releaseFence); | 
|  |  | 
|  | // 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. | 
|  | // | 
|  | // consumer may not be NULL. | 
|  | 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 have been released by the BufferQueue | 
|  | // but have not yet been released by the consumer. | 
|  | // | 
|  | // This should be called from the onBuffersReleased() callback. | 
|  | status_t getReleasedBuffers(uint32_t* slotMask); | 
|  |  | 
|  | // setDefaultBufferSize is used to set the size of buffers returned by | 
|  | // dequeueBuffer when a width and height of zero is requested.  Default | 
|  | // is 1x1. | 
|  | status_t setDefaultBufferSize(uint32_t w, uint32_t h); | 
|  |  | 
|  | // setDefaultMaxBufferCount sets the default value for the maximum buffer | 
|  | // count (the initial default is 2). If the producer has requested a | 
|  | // buffer count using setBufferCount, the default buffer count will only | 
|  | // take effect if the producer sets the count back to zero. | 
|  | // | 
|  | // The count must be between 2 and NUM_BUFFER_SLOTS, inclusive. | 
|  | status_t setDefaultMaxBufferCount(int bufferCount); | 
|  |  | 
|  | // setMaxAcquiredBufferCount sets the maximum number of buffers that can | 
|  | // be acquired by the consumer at one time (default 1).  This call will | 
|  | // fail if a producer is connected to the BufferQueue. | 
|  | status_t setMaxAcquiredBufferCount(int maxAcquiredBuffers); | 
|  |  | 
|  | // isSynchronousMode returns whether the BufferQueue 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.  Formats are enumerated in graphics.h; the | 
|  | // initial default is HAL_PIXEL_FORMAT_RGBA_8888. | 
|  | status_t setDefaultBufferFormat(uint32_t defaultFormat); | 
|  |  | 
|  | // setConsumerUsageBits will turn on additional usage bits for dequeueBuffer. | 
|  | // These are merged with the bits passed to dequeueBuffer.  The values are | 
|  | // enumerated in gralloc.h, e.g. GRALLOC_USAGE_HW_RENDER; the default is 0. | 
|  | status_t setConsumerUsageBits(uint32_t usage); | 
|  |  | 
|  | // setTransformHint bakes in rotation to buffers so overlays can be used. | 
|  | // The values are enumerated in window.h, e.g. | 
|  | // NATIVE_WINDOW_TRANSFORM_ROT_90.  The default is 0 (no transform). | 
|  | status_t setTransformHint(uint32_t hint); | 
|  |  | 
|  | private: | 
|  | // freeBufferLocked frees the GraphicBuffer and sync resources for the | 
|  | // given slot. | 
|  | void freeBufferLocked(int index); | 
|  |  | 
|  | // freeAllBuffersLocked frees the GraphicBuffer and sync resources for | 
|  | // all slots. | 
|  | void freeAllBuffersLocked(); | 
|  |  | 
|  | // freeAllBuffersExceptHeadLocked frees the GraphicBuffer and sync | 
|  | // resources for all slots except the head of mQueue. | 
|  | void freeAllBuffersExceptHeadLocked(); | 
|  |  | 
|  | // drainQueueLocked waits for the buffer queue to empty if we're in | 
|  | // synchronous mode, or returns immediately otherwise. It returns NO_INIT | 
|  | // if the BufferQueue is abandoned (consumer disconnected) or disconnected | 
|  | // (producer disconnected) during the 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 currently queued buffer (if it exists). | 
|  | status_t drainQueueAndFreeBuffersLocked(); | 
|  |  | 
|  | // setDefaultMaxBufferCountLocked sets the maximum number of buffer slots | 
|  | // that will be used if the producer does not override the buffer slot | 
|  | // count.  The count must be between 2 and NUM_BUFFER_SLOTS, inclusive. | 
|  | // The initial default is 2. | 
|  | status_t setDefaultMaxBufferCountLocked(int count); | 
|  |  | 
|  | // getMinBufferCountLocked returns the minimum number of buffers allowed | 
|  | // given the current BufferQueue state. | 
|  | int getMinMaxBufferCountLocked() const; | 
|  |  | 
|  | // getMinUndequeuedBufferCountLocked returns the minimum number of buffers | 
|  | // that must remain in a state other than DEQUEUED. | 
|  | int getMinUndequeuedBufferCountLocked() const; | 
|  |  | 
|  | // getMaxBufferCountLocked returns the maximum number of buffers that can | 
|  | // be allocated at once.  This value depends upon the following member | 
|  | // variables: | 
|  | // | 
|  | //      mSynchronousMode | 
|  | //      mMaxAcquiredBufferCount | 
|  | //      mDefaultMaxBufferCount | 
|  | //      mOverrideMaxBufferCount | 
|  | // | 
|  | // Any time one of these member variables is changed while a producer is | 
|  | // connected, mDequeueCondition must be broadcast. | 
|  | int getMaxBufferCountLocked() const; | 
|  |  | 
|  | struct BufferSlot { | 
|  |  | 
|  | BufferSlot() | 
|  | : mEglDisplay(EGL_NO_DISPLAY), | 
|  | mBufferState(BufferSlot::FREE), | 
|  | mRequestBufferCalled(false), | 
|  | mTransform(0), | 
|  | mScalingMode(NATIVE_WINDOW_SCALING_MODE_FREEZE), | 
|  | mTimestamp(0), | 
|  | mFrameNumber(0), | 
|  | mEglFence(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 EGLSyncKHR objects. | 
|  | EGLDisplay mEglDisplay; | 
|  |  | 
|  | // BufferState represents the different states in which a buffer slot | 
|  | // can be.  All slots are initially FREE. | 
|  | enum BufferState { | 
|  | // FREE indicates that the buffer is available to be dequeued | 
|  | // by the producer.  The buffer may be in use by the consumer for | 
|  | // a finite time, so the buffer must not be modified until the | 
|  | // associated fence is signaled. | 
|  | // | 
|  | // The slot is "owned" by BufferQueue.  It transitions to DEQUEUED | 
|  | // when dequeueBuffer is called. | 
|  | FREE = 0, | 
|  |  | 
|  | // DEQUEUED indicates that the buffer has been dequeued by the | 
|  | // producer, but has not yet been queued or canceled.  The | 
|  | // producer may modify the buffer's contents as soon as the | 
|  | // associated ready fence is signaled. | 
|  | // | 
|  | // The slot is "owned" by the producer.  It can transition to | 
|  | // QUEUED (via queueBuffer) or back to FREE (via cancelBuffer). | 
|  | DEQUEUED = 1, | 
|  |  | 
|  | // QUEUED indicates that the buffer has been filled by the | 
|  | // producer and queued for use by the consumer.  The buffer | 
|  | // contents may continue to be modified for a finite time, so | 
|  | // the contents must not be accessed until the associated fence | 
|  | // is signaled. | 
|  | // | 
|  | // The slot is "owned" by BufferQueue.  It can transition to | 
|  | // ACQUIRED (via acquireBuffer) or to FREE (if another buffer is | 
|  | // queued in asynchronous mode). | 
|  | QUEUED = 2, | 
|  |  | 
|  | // ACQUIRED indicates that the buffer has been acquired by the | 
|  | // consumer.  As with QUEUED, the contents must not be accessed | 
|  | // by the consumer until the fence is signaled. | 
|  | // | 
|  | // The slot is "owned" by the consumer.  It transitions to FREE | 
|  | // when releaseBuffer is called. | 
|  | ACQUIRED = 3 | 
|  | }; | 
|  |  | 
|  | // mBufferState is the current state of this buffer slot. | 
|  | BufferState mBufferState; | 
|  |  | 
|  | // mRequestBufferCalled is used for validating that the producer did | 
|  | // call requestBuffer() when told to do so. Technically this is not | 
|  | // needed but useful for debugging and catching producer 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. | 
|  | // (example: NATIVE_WINDOW_TRANSFORM_ROT_90) | 
|  | uint32_t mTransform; | 
|  |  | 
|  | // mScalingMode is the current scaling mode for this buffer slot. | 
|  | // (example: NATIVE_WINDOW_SCALING_MODE_FREEZE) | 
|  | 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.  This | 
|  | // is used to dequeue buffers in LRU order (useful because buffers | 
|  | // may be released before their release fence is signaled). | 
|  | uint64_t mFrameNumber; | 
|  |  | 
|  | // mEglFence 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 may be set to a | 
|  | // new sync object in releaseBuffer.  (This is deprecated in favor of | 
|  | // mFence, below.) | 
|  | EGLSyncKHR mEglFence; | 
|  |  | 
|  | // mFence is a fence which will signal when work initiated by the | 
|  | // previous owner of the buffer is finished. When the buffer is FREE, | 
|  | // the fence indicates when the consumer has finished reading | 
|  | // from the buffer, or when the producer has finished writing if it | 
|  | // called cancelBuffer after queueing some writes. When the buffer is | 
|  | // QUEUED, it indicates when the producer has finished filling the | 
|  | // buffer. When the buffer is DEQUEUED or ACQUIRED, the fence has been | 
|  | // passed to the consumer or producer along with ownership of the | 
|  | // buffer, and mFence is set to NO_FENCE. | 
|  | sp<Fence> mFence; | 
|  |  | 
|  | // Indicates whether this buffer has been seen by a consumer yet | 
|  | bool mAcquireCalled; | 
|  |  | 
|  | // Indicates whether this buffer needs to be cleaned up by the | 
|  | // consumer.  This is set when a buffer in ACQUIRED state is freed. | 
|  | // It causes releaseBuffer to return STALE_BUFFER_SLOT. | 
|  | bool mNeedsCleanupOnRelease; | 
|  | }; | 
|  |  | 
|  | // mSlots is the array of buffer slots that must be mirrored on the | 
|  | // producer side. This allows buffer ownership to be transferred between | 
|  | // the producer and consumer 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 dequeueBuffer() if a width and height of zero is specified. | 
|  | uint32_t mDefaultWidth; | 
|  |  | 
|  | // mDefaultHeight holds the default height of allocated buffers. It is used | 
|  | // in dequeueBuffer() if a width and height of zero is specified. | 
|  | uint32_t mDefaultHeight; | 
|  |  | 
|  | // mMaxAcquiredBufferCount is the number of buffers that the consumer may | 
|  | // acquire at one time.  It defaults to 1 and can be changed by the | 
|  | // consumer via the setMaxAcquiredBufferCount method, but this may only be | 
|  | // done when no producer is connected to the BufferQueue. | 
|  | // | 
|  | // This value is used to derive the value returned for the | 
|  | // MIN_UNDEQUEUED_BUFFERS query by the producer. | 
|  | int mMaxAcquiredBufferCount; | 
|  |  | 
|  | // mDefaultMaxBufferCount is the default limit on the number of buffers | 
|  | // that will be allocated at one time.  This default limit is set by the | 
|  | // consumer.  The limit (as opposed to the default limit) may be | 
|  | // overridden by the producer. | 
|  | int mDefaultMaxBufferCount; | 
|  |  | 
|  | // mOverrideMaxBufferCount is the limit on the number of buffers that will | 
|  | // be allocated at one time. This value is set by the image producer by | 
|  | // calling setBufferCount. The default is zero, which means the producer | 
|  | // doesn't care about the number of buffers in the pool. In that case | 
|  | // mDefaultMaxBufferCount is used as the limit. | 
|  | int mOverrideMaxBufferCount; | 
|  |  | 
|  | // 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.  Set | 
|  | // when the BufferQueue is created (by the consumer). | 
|  | const bool mAllowSynchronousMode; | 
|  |  | 
|  | // mConnectedApi indicates the producer 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 image buffers pushed to it using the IGraphicBufferProducer | 
|  | // interface.  It is initialized to false, and set to true in the | 
|  | // consumerDisconnect method.  A BufferQueue that has been abandoned will | 
|  | // return the NO_INIT error from all IGraphicBufferProducer methods | 
|  | // capable of returning an error. | 
|  | bool mAbandoned; | 
|  |  | 
|  | // mConsumerName is a string used to identify the BufferQueue in log | 
|  | // messages.  It is set by the setConsumerName 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 on every | 
|  | // successful queueBuffer call. | 
|  | uint64_t mFrameCounter; | 
|  |  | 
|  | // mBufferHasBeenQueued is true once a buffer has been queued.  It is | 
|  | // reset when something causes all buffers to be freed (e.g. 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 |