/* * Copyright 2014 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_BUFFERQUEUEPRODUCER_H #define ANDROID_GUI_BUFFERQUEUEPRODUCER_H #include #include namespace android { class BufferSlot; class BufferQueueProducer : public BnGraphicBufferProducer, private IBinder::DeathRecipient { public: friend class BufferQueue; // Needed to access binderDied BufferQueueProducer(const sp& core); virtual ~BufferQueueProducer(); // 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 It must be called again if dequeueBuffer returns // flags indicating that previously-returned buffers are no longer valid.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* buf); // 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 (exclusive) 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); // 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 outFence 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. // // 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 *outSlot, sp* outFence, bool async, uint32_t width, uint32_t height, PixelFormat format, uint32_t usage); // See IGraphicBufferProducer::detachBuffer virtual status_t detachBuffer(int slot); // See IGraphicBufferProducer::detachNextBuffer virtual status_t detachNextBuffer(sp* outBuffer, sp* outFence); // See IGraphicBufferProducer::attachBuffer virtual status_t attachBuffer(int* outSlot, const sp& buffer); // 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 slot, 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 slot, const sp& fence); // Query native window attributes. The "what" values are enumerated in // window.h (e.g. NATIVE_WINDOW_FORMAT). virtual int query(int what, int* outValue); // 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(const sp& listener, int api, bool producerControlledByApp, 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); // Attaches a sideband buffer stream to the IGraphicBufferProducer. // // A sideband stream is a device-specific mechanism for passing buffers // from the producer to the consumer without using dequeueBuffer/ // queueBuffer. If a sideband stream is present, the consumer can choose // whether to acquire buffers from the sideband stream or from the queued // buffers. // // Passing NULL or a different stream handle will detach the previous // handle if any. virtual status_t setSidebandStream(const sp& stream); // See IGraphicBufferProducer::allocateBuffers virtual void allocateBuffers(bool async, uint32_t width, uint32_t height, PixelFormat format, uint32_t usage); // See IGraphicBufferProducer::allowAllocation virtual status_t allowAllocation(bool allow); // See IGraphicBufferProducer::setGenerationNumber virtual status_t setGenerationNumber(uint32_t generationNumber); private: // This is required by the IBinder::DeathRecipient interface virtual void binderDied(const wp& who); // waitForFreeSlotThenRelock finds the oldest slot in the FREE state. It may // block if there are no available slots and we are not in non-blocking // mode (producer and consumer controlled by the application). If it blocks, // it will release mCore->mMutex while blocked so that other operations on // the BufferQueue may succeed. status_t waitForFreeSlotThenRelock(const char* caller, bool async, int* found, status_t* returnFlags) const; sp mCore; // This references mCore->mSlots. Lock mCore->mMutex while accessing. BufferQueueDefs::SlotsType& mSlots; // This is a cached copy of the name stored in the BufferQueueCore. // It's updated during connect and dequeueBuffer (which should catch // most updates). String8 mConsumerName; uint32_t mStickyTransform; // This saves the fence from the last queueBuffer, such that the // next queueBuffer call can throttle buffer production. The prior // queueBuffer's fence is not nessessarily available elsewhere, // since the previous buffer might have already been acquired. sp mLastQueueBufferFence; // Take-a-ticket system for ensuring that onFrame* callbacks are called in // the order that frames are queued. While the BufferQueue lock // (mCore->mMutex) is held, a ticket is retained by the producer. After // dropping the BufferQueue lock, the producer must wait on the condition // variable until the current callback ticket matches its retained ticket. Mutex mCallbackMutex; int mNextCallbackTicket; // Protected by mCore->mMutex int mCurrentCallbackTicket; // Protected by mCallbackMutex Condition mCallbackCondition; }; // class BufferQueueProducer } // namespace android #endif