BufferQueueProducer.h revision 399184a4cd728ea1421fb0bc1722274a29e38f4a
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 23namespace android { 24 25class BufferSlot; 26 27class BufferQueueProducer : public BnGraphicBufferProducer, 28 private IBinder::DeathRecipient { 29public: 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 It must be called again if dequeueBuffer returns 39 // flags indicating that previously-returned buffers are no longer valid. 40 virtual status_t requestBuffer(int slot, sp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 // The pixel formats are enumerated in graphics.h, e.g. 77 // HAL_PIXEL_FORMAT_RGBA_8888. If the format is 0, the default format 78 // will be used. 79 // 80 // The usage argument specifies gralloc buffer usage flags. The values 81 // are enumerated in gralloc.h, e.g. GRALLOC_USAGE_HW_RENDER. These 82 // will be merged with the usage flags specified by setConsumerUsageBits. 83 // 84 // The return value may be a negative error value or a non-negative 85 // collection of flags. If the flags are set, the return values are 86 // valid, but additional actions must be performed. 87 // 88 // If IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION is set, the 89 // producer must discard cached GraphicBuffer references for the slot 90 // returned in buf. 91 // If IGraphicBufferProducer::RELEASE_ALL_BUFFERS is set, the producer 92 // must discard cached GraphicBuffer references for all slots. 93 // 94 // In both cases, the producer will need to call requestBuffer to get a 95 // GraphicBuffer handle for the returned slot. 96 virtual status_t dequeueBuffer(int *outSlot, sp<Fence>* outFence, bool async, 97 uint32_t width, uint32_t height, uint32_t format, uint32_t usage); 98 99 // queueBuffer returns a filled buffer to the BufferQueue. 100 // 101 // Additional data is provided in the QueueBufferInput struct. Notably, 102 // a timestamp must be provided for the buffer. The timestamp is in 103 // nanoseconds, and must be monotonically increasing. Its other semantics 104 // (zero point, etc) are producer-specific and should be documented by the 105 // producer. 106 // 107 // The caller may provide a fence that signals when all rendering 108 // operations have completed. Alternatively, NO_FENCE may be used, 109 // indicating that the buffer is ready immediately. 110 // 111 // Some values are returned in the output struct: the current settings 112 // for default width and height, the current transform hint, and the 113 // number of queued buffers. 114 virtual status_t queueBuffer(int slot, 115 const QueueBufferInput& input, QueueBufferOutput* output); 116 117 // cancelBuffer returns a dequeued buffer to the BufferQueue, but doesn't 118 // queue it for use by the consumer. 119 // 120 // The buffer will not be overwritten until the fence signals. The fence 121 // will usually be the one obtained from dequeueBuffer. 122 virtual void cancelBuffer(int slot, const sp<Fence>& fence); 123 124 // Query native window attributes. The "what" values are enumerated in 125 // window.h (e.g. NATIVE_WINDOW_FORMAT). 126 virtual int query(int what, int* outValue); 127 128 // connect attempts to connect a producer API to the BufferQueue. This 129 // must be called before any other IGraphicBufferProducer methods are 130 // called except for getAllocator. A consumer must already be connected. 131 // 132 // This method will fail if connect was previously called on the 133 // BufferQueue and no corresponding disconnect call was made (i.e. if 134 // it's still connected to a producer). 135 // 136 // APIs are enumerated in window.h (e.g. NATIVE_WINDOW_API_CPU). 137 virtual status_t connect(const sp<IBinder>& token, 138 int api, bool producerControlledByApp, QueueBufferOutput* output); 139 140 // disconnect attempts to disconnect a producer API from the BufferQueue. 141 // Calling this method will cause any subsequent calls to other 142 // IGraphicBufferProducer methods to fail except for getAllocator and connect. 143 // Successfully calling connect after this will allow the other methods to 144 // succeed again. 145 // 146 // This method will fail if the the BufferQueue is not currently 147 // connected to the specified producer API. 148 virtual status_t disconnect(int api); 149 150 // Attaches a sideband buffer stream to the IGraphicBufferProducer. 151 // 152 // A sideband stream is a device-specific mechanism for passing buffers 153 // from the producer to the consumer without using dequeueBuffer/ 154 // queueBuffer. If a sideband stream is present, the consumer can choose 155 // whether to acquire buffers from the sideband stream or from the queued 156 // buffers. 157 // 158 // Passing NULL or a different stream handle will detach the previous 159 // handle if any. 160 virtual status_t setSidebandStream(const sp<NativeHandle>& stream); 161 162private: 163 // This is required by the IBinder::DeathRecipient interface 164 virtual void binderDied(const wp<IBinder>& who); 165 166 sp<BufferQueueCore> mCore; 167 168 // This references mCore->mSlots. Lock mCore->mMutex while accessing. 169 BufferQueueDefs::SlotsType& mSlots; 170 171 // This is a cached copy of the name stored in the BufferQueueCore. 172 // It's updated during connect and dequeueBuffer (which should catch 173 // most updates). 174 String8 mConsumerName; 175 176}; // class BufferQueueProducer 177 178} // namespace android 179 180#endif 181