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 It must be called again if dequeueBuffer returns 39 // flags indicating that previously-returned buffers are no longer valid. 40 virtual status_t requestBuffer(int slot, sp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 // see IGraphicsBufferProducer::setMaxDequeuedBufferCount 43 virtual status_t setMaxDequeuedBufferCount(int maxDequeuedBuffers); 44 45 // see IGraphicsBufferProducer::setAsyncMode 46 virtual status_t setAsyncMode(bool async); 47 48 // dequeueBuffer gets the next buffer slot index for the producer to use. 49 // If a buffer slot is available then that slot index is written to the 50 // location pointed to by the buf argument and a status of OK is returned. 51 // If no slot is available then a status of -EBUSY is returned and buf is 52 // unmodified. 53 // 54 // The outFence parameter will be updated to hold the fence associated with 55 // the buffer. The contents of the buffer must not be overwritten until the 56 // fence signals. If the fence is Fence::NO_FENCE, the buffer may be 57 // written immediately. 58 // 59 // The width and height parameters must be no greater than the minimum of 60 // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). 61 // An error due to invalid dimensions might not be reported until 62 // updateTexImage() is called. If width and height are both zero, the 63 // default values specified by setDefaultBufferSize() are used instead. 64 // 65 // If the format is 0, the default format will be used. 66 // 67 // The usage argument specifies gralloc buffer usage flags. The values 68 // are enumerated in gralloc.h, e.g. GRALLOC_USAGE_HW_RENDER. These 69 // will be merged with the usage flags specified by setConsumerUsageBits. 70 // 71 // The return value may be a negative error value or a non-negative 72 // collection of flags. If the flags are set, the return values are 73 // valid, but additional actions must be performed. 74 // 75 // If IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION is set, the 76 // producer must discard cached GraphicBuffer references for the slot 77 // returned in buf. 78 // If IGraphicBufferProducer::RELEASE_ALL_BUFFERS is set, the producer 79 // must discard cached GraphicBuffer references for all slots. 80 // 81 // In both cases, the producer will need to call requestBuffer to get a 82 // GraphicBuffer handle for the returned slot. 83 virtual status_t dequeueBuffer(int *outSlot, sp<Fence>* outFence, 84 uint32_t width, uint32_t height, PixelFormat format, 85 uint32_t usage); 86 87 // See IGraphicBufferProducer::detachBuffer 88 virtual status_t detachBuffer(int slot); 89 90 // See IGraphicBufferProducer::detachNextBuffer 91 virtual status_t detachNextBuffer(sp<GraphicBuffer>* outBuffer, 92 sp<Fence>* outFence); 93 94 // See IGraphicBufferProducer::attachBuffer 95 virtual status_t attachBuffer(int* outSlot, const sp<GraphicBuffer>& buffer); 96 97 // queueBuffer returns a filled buffer to the BufferQueue. 98 // 99 // Additional data is provided in the QueueBufferInput struct. Notably, 100 // a timestamp must be provided for the buffer. The timestamp is in 101 // nanoseconds, and must be monotonically increasing. Its other semantics 102 // (zero point, etc) are producer-specific and should be documented by the 103 // producer. 104 // 105 // The caller may provide a fence that signals when all rendering 106 // operations have completed. Alternatively, NO_FENCE may be used, 107 // indicating that the buffer is ready immediately. 108 // 109 // Some values are returned in the output struct: the current settings 110 // for default width and height, the current transform hint, and the 111 // number of queued buffers. 112 virtual status_t queueBuffer(int slot, 113 const QueueBufferInput& input, QueueBufferOutput* output); 114 115 // cancelBuffer returns a dequeued buffer to the BufferQueue, but doesn't 116 // queue it for use by the consumer. 117 // 118 // The buffer will not be overwritten until the fence signals. The fence 119 // will usually be the one obtained from dequeueBuffer. 120 virtual status_t cancelBuffer(int slot, const sp<Fence>& fence); 121 122 // Query native window attributes. The "what" values are enumerated in 123 // window.h (e.g. NATIVE_WINDOW_FORMAT). 124 virtual int query(int what, int* outValue); 125 126 // connect attempts to connect a producer API to the BufferQueue. This 127 // must be called before any other IGraphicBufferProducer methods are 128 // called except for getAllocator. A consumer must already be connected. 129 // 130 // This method will fail if connect was previously called on the 131 // BufferQueue and no corresponding disconnect call was made (i.e. if 132 // it's still connected to a producer). 133 // 134 // APIs are enumerated in window.h (e.g. NATIVE_WINDOW_API_CPU). 135 virtual status_t connect(const sp<IProducerListener>& listener, 136 int api, bool producerControlledByApp, QueueBufferOutput* output); 137 138 // disconnect attempts to disconnect a producer API from the BufferQueue. 139 // Calling this method will cause any subsequent calls to other 140 // IGraphicBufferProducer methods to fail except for getAllocator and connect. 141 // Successfully calling connect after this will allow the other methods to 142 // succeed again. 143 // 144 // This method will fail if the the BufferQueue is not currently 145 // connected to the specified producer API. 146 virtual status_t disconnect(int api); 147 148 // Attaches a sideband buffer stream to the IGraphicBufferProducer. 149 // 150 // A sideband stream is a device-specific mechanism for passing buffers 151 // from the producer to the consumer without using dequeueBuffer/ 152 // queueBuffer. If a sideband stream is present, the consumer can choose 153 // whether to acquire buffers from the sideband stream or from the queued 154 // buffers. 155 // 156 // Passing NULL or a different stream handle will detach the previous 157 // handle if any. 158 virtual status_t setSidebandStream(const sp<NativeHandle>& stream); 159 160 // See IGraphicBufferProducer::allocateBuffers 161 virtual void allocateBuffers(uint32_t width, uint32_t height, 162 PixelFormat format, uint32_t usage); 163 164 // See IGraphicBufferProducer::allowAllocation 165 virtual status_t allowAllocation(bool allow); 166 167 // See IGraphicBufferProducer::setGenerationNumber 168 virtual status_t setGenerationNumber(uint32_t generationNumber); 169 170 // See IGraphicBufferProducer::getConsumerName 171 virtual String8 getConsumerName() const override; 172 173 // See IGraphicBufferProducer::getNextFrameNumber 174 virtual uint64_t getNextFrameNumber() const override; 175 176 // See IGraphicBufferProducer::setSharedBufferMode 177 virtual status_t setSharedBufferMode(bool sharedBufferMode) override; 178 179 // See IGraphicBufferProducer::setAutoRefresh 180 virtual status_t setAutoRefresh(bool autoRefresh) override; 181 182 // See IGraphicBufferProducer::setDequeueTimeout 183 virtual status_t setDequeueTimeout(nsecs_t timeout) override; 184 185 // See IGraphicBufferProducer::getLastQueuedBuffer 186 virtual status_t getLastQueuedBuffer(sp<GraphicBuffer>* outBuffer, 187 sp<Fence>* outFence, float outTransformMatrix[16]) override; 188 189 // See IGraphicBufferProducer::getUniqueId 190 virtual status_t getUniqueId(uint64_t* outId) const override; 191 192 private: 193 // This is required by the IBinder::DeathRecipient interface 194 virtual void binderDied(const wp<IBinder>& who); 195 196 // Returns the slot of the next free buffer if one is available or 197 // BufferQueueCore::INVALID_BUFFER_SLOT otherwise 198 int getFreeBufferLocked() const; 199 200 // Returns the next free slot if one is available or 201 // BufferQueueCore::INVALID_BUFFER_SLOT otherwise 202 int getFreeSlotLocked() const; 203 204 // waitForFreeSlotThenRelock finds the oldest slot in the FREE state. It may 205 // block if there are no available slots and we are not in non-blocking 206 // mode (producer and consumer controlled by the application). If it blocks, 207 // it will release mCore->mMutex while blocked so that other operations on 208 // the BufferQueue may succeed. 209 enum class FreeSlotCaller { 210 Dequeue, 211 Attach, 212 }; 213 status_t waitForFreeSlotThenRelock(FreeSlotCaller caller, int* found) const; 214 215 sp<BufferQueueCore> mCore; 216 217 // This references mCore->mSlots. Lock mCore->mMutex while accessing. 218 BufferQueueDefs::SlotsType& mSlots; 219 220 // This is a cached copy of the name stored in the BufferQueueCore. 221 // It's updated during connect and dequeueBuffer (which should catch 222 // most updates). 223 String8 mConsumerName; 224 225 uint32_t mStickyTransform; 226 227 // This saves the fence from the last queueBuffer, such that the 228 // next queueBuffer call can throttle buffer production. The prior 229 // queueBuffer's fence is not nessessarily available elsewhere, 230 // since the previous buffer might have already been acquired. 231 sp<Fence> mLastQueueBufferFence; 232 233 Rect mLastQueuedCrop; 234 uint32_t mLastQueuedTransform; 235 236 // Take-a-ticket system for ensuring that onFrame* callbacks are called in 237 // the order that frames are queued. While the BufferQueue lock 238 // (mCore->mMutex) is held, a ticket is retained by the producer. After 239 // dropping the BufferQueue lock, the producer must wait on the condition 240 // variable until the current callback ticket matches its retained ticket. 241 Mutex mCallbackMutex; 242 int mNextCallbackTicket; // Protected by mCore->mMutex 243 int mCurrentCallbackTicket; // Protected by mCallbackMutex 244 Condition mCallbackCondition; 245 246 // Sets how long dequeueBuffer or attachBuffer will block if a buffer or 247 // slot is not yet available. 248 nsecs_t mDequeueTimeout; 249 250 }; // class BufferQueueProducer 251 252 } // namespace android 253 254 #endif 255