1 /* 2 * Copyright 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ANDROID_GUI_BUFFERQUEUEPRODUCER_H 18 #define ANDROID_GUI_BUFFERQUEUEPRODUCER_H 19 20 #include <gui/BufferQueueDefs.h> 21 #include <gui/IGraphicBufferProducer.h> 22 23 namespace android { 24 25 class BufferSlot; 26 27 class BufferQueueProducer : public BnGraphicBufferProducer, 28 private IBinder::DeathRecipient { 29 public: 30 friend class BufferQueue; // Needed to access binderDied 31 32 BufferQueueProducer(const sp<BufferQueueCore>& core); 33 virtual ~BufferQueueProducer(); 34 35 // requestBuffer returns the GraphicBuffer for slot N. 36 // 37 // In normal operation, this is called the first time slot N is returned 38 // by dequeueBuffer. It must be called again if dequeueBuffer returns 39 // flags indicating that previously-returned buffers are no longer valid. 40 virtual status_t requestBuffer(int slot, sp<GraphicBuffer>* buf); 41 42 // setBufferCount updates the number of available buffer slots. If this 43 // method succeeds, buffer slots will be both unallocated and owned by 44 // the BufferQueue object (i.e. they are not owned by the producer or 45 // consumer). 46 // 47 // This will fail if the producer has dequeued any buffers, or if 48 // bufferCount is invalid. bufferCount must generally be a value 49 // between the minimum undequeued buffer count (exclusive) and NUM_BUFFER_SLOTS 50 // (inclusive). It may also be set to zero (the default) to indicate 51 // that the producer does not wish to set a value. The minimum value 52 // can be obtained by calling query(NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS, 53 // ...). 54 // 55 // This may only be called by the producer. The consumer will be told 56 // to discard buffers through the onBuffersReleased callback. 57 virtual status_t setBufferCount(int bufferCount); 58 59 // dequeueBuffer gets the next buffer slot index for the producer to use. 60 // If a buffer slot is available then that slot index is written to the 61 // location pointed to by the buf argument and a status of OK is returned. 62 // If no slot is available then a status of -EBUSY is returned and buf is 63 // unmodified. 64 // 65 // The outFence parameter will be updated to hold the fence associated with 66 // the buffer. The contents of the buffer must not be overwritten until the 67 // fence signals. If the fence is Fence::NO_FENCE, the buffer may be 68 // written immediately. 69 // 70 // The width and height parameters must be no greater than the minimum of 71 // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). 72 // An error due to invalid dimensions might not be reported until 73 // updateTexImage() is called. If width and height are both zero, the 74 // default values specified by setDefaultBufferSize() are used instead. 75 // 76 // If the format is 0, the default format will be used. 77 // 78 // The usage argument specifies gralloc buffer usage flags. The values 79 // are enumerated in gralloc.h, e.g. GRALLOC_USAGE_HW_RENDER. These 80 // will be merged with the usage flags specified by setConsumerUsageBits. 81 // 82 // The return value may be a negative error value or a non-negative 83 // collection of flags. If the flags are set, the return values are 84 // valid, but additional actions must be performed. 85 // 86 // If IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION is set, the 87 // producer must discard cached GraphicBuffer references for the slot 88 // returned in buf. 89 // If IGraphicBufferProducer::RELEASE_ALL_BUFFERS is set, the producer 90 // must discard cached GraphicBuffer references for all slots. 91 // 92 // In both cases, the producer will need to call requestBuffer to get a 93 // GraphicBuffer handle for the returned slot. 94 virtual status_t dequeueBuffer(int *outSlot, sp<Fence>* outFence, 95 bool async, uint32_t width, uint32_t height, PixelFormat format, 96 uint32_t usage); 97 98 // See IGraphicBufferProducer::detachBuffer 99 virtual status_t detachBuffer(int slot); 100 101 // See IGraphicBufferProducer::detachNextBuffer 102 virtual status_t detachNextBuffer(sp<GraphicBuffer>* outBuffer, 103 sp<Fence>* outFence); 104 105 // See IGraphicBufferProducer::attachBuffer 106 virtual status_t attachBuffer(int* outSlot, const sp<GraphicBuffer>& buffer); 107 108 // queueBuffer returns a filled buffer to the BufferQueue. 109 // 110 // Additional data is provided in the QueueBufferInput struct. Notably, 111 // a timestamp must be provided for the buffer. The timestamp is in 112 // nanoseconds, and must be monotonically increasing. Its other semantics 113 // (zero point, etc) are producer-specific and should be documented by the 114 // producer. 115 // 116 // The caller may provide a fence that signals when all rendering 117 // operations have completed. Alternatively, NO_FENCE may be used, 118 // indicating that the buffer is ready immediately. 119 // 120 // Some values are returned in the output struct: the current settings 121 // for default width and height, the current transform hint, and the 122 // number of queued buffers. 123 virtual status_t queueBuffer(int slot, 124 const QueueBufferInput& input, QueueBufferOutput* output); 125 126 // cancelBuffer returns a dequeued buffer to the BufferQueue, but doesn't 127 // queue it for use by the consumer. 128 // 129 // The buffer will not be overwritten until the fence signals. The fence 130 // will usually be the one obtained from dequeueBuffer. 131 virtual void cancelBuffer(int slot, const sp<Fence>& fence); 132 133 // Query native window attributes. The "what" values are enumerated in 134 // window.h (e.g. NATIVE_WINDOW_FORMAT). 135 virtual int query(int what, int* outValue); 136 137 // connect attempts to connect a producer API to the BufferQueue. This 138 // must be called before any other IGraphicBufferProducer methods are 139 // called except for getAllocator. A consumer must already be connected. 140 // 141 // This method will fail if connect was previously called on the 142 // BufferQueue and no corresponding disconnect call was made (i.e. if 143 // it's still connected to a producer). 144 // 145 // APIs are enumerated in window.h (e.g. NATIVE_WINDOW_API_CPU). 146 virtual status_t connect(const sp<IProducerListener>& listener, 147 int api, bool producerControlledByApp, QueueBufferOutput* output); 148 149 // disconnect attempts to disconnect a producer API from the BufferQueue. 150 // Calling this method will cause any subsequent calls to other 151 // IGraphicBufferProducer methods to fail except for getAllocator and connect. 152 // Successfully calling connect after this will allow the other methods to 153 // succeed again. 154 // 155 // This method will fail if the the BufferQueue is not currently 156 // connected to the specified producer API. 157 virtual status_t disconnect(int api); 158 159 // Attaches a sideband buffer stream to the IGraphicBufferProducer. 160 // 161 // A sideband stream is a device-specific mechanism for passing buffers 162 // from the producer to the consumer without using dequeueBuffer/ 163 // queueBuffer. If a sideband stream is present, the consumer can choose 164 // whether to acquire buffers from the sideband stream or from the queued 165 // buffers. 166 // 167 // Passing NULL or a different stream handle will detach the previous 168 // handle if any. 169 virtual status_t setSidebandStream(const sp<NativeHandle>& stream); 170 171 // See IGraphicBufferProducer::allocateBuffers 172 virtual void allocateBuffers(bool async, uint32_t width, uint32_t height, 173 PixelFormat format, uint32_t usage); 174 175 // See IGraphicBufferProducer::allowAllocation 176 virtual status_t allowAllocation(bool allow); 177 178 // See IGraphicBufferProducer::setGenerationNumber 179 virtual status_t setGenerationNumber(uint32_t generationNumber); 180 181 // See IGraphicBufferProducer::getConsumerName 182 virtual String8 getConsumerName() const override; 183 184 private: 185 // This is required by the IBinder::DeathRecipient interface 186 virtual void binderDied(const wp<IBinder>& who); 187 188 // waitForFreeSlotThenRelock finds the oldest slot in the FREE state. It may 189 // block if there are no available slots and we are not in non-blocking 190 // mode (producer and consumer controlled by the application). If it blocks, 191 // it will release mCore->mMutex while blocked so that other operations on 192 // the BufferQueue may succeed. 193 status_t waitForFreeSlotThenRelock(const char* caller, bool async, 194 int* found, status_t* returnFlags) const; 195 196 sp<BufferQueueCore> mCore; 197 198 // This references mCore->mSlots. Lock mCore->mMutex while accessing. 199 BufferQueueDefs::SlotsType& mSlots; 200 201 // This is a cached copy of the name stored in the BufferQueueCore. 202 // It's updated during connect and dequeueBuffer (which should catch 203 // most updates). 204 String8 mConsumerName; 205 206 uint32_t mStickyTransform; 207 208 // This saves the fence from the last queueBuffer, such that the 209 // next queueBuffer call can throttle buffer production. The prior 210 // queueBuffer's fence is not nessessarily available elsewhere, 211 // since the previous buffer might have already been acquired. 212 sp<Fence> mLastQueueBufferFence; 213 214 // Take-a-ticket system for ensuring that onFrame* callbacks are called in 215 // the order that frames are queued. While the BufferQueue lock 216 // (mCore->mMutex) is held, a ticket is retained by the producer. After 217 // dropping the BufferQueue lock, the producer must wait on the condition 218 // variable until the current callback ticket matches its retained ticket. 219 Mutex mCallbackMutex; 220 int mNextCallbackTicket; // Protected by mCore->mMutex 221 int mCurrentCallbackTicket; // Protected by mCallbackMutex 222 Condition mCallbackCondition; 223 224 }; // class BufferQueueProducer 225 226 } // namespace android 227 228 #endif 229