BufferQueueCore.h revision 3e96f1982fda358424b0b75f394cbf7c1794a072
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_BUFFERQUEUECORE_H 18#define ANDROID_GUI_BUFFERQUEUECORE_H 19 20#include <gui/BufferQueueDefs.h> 21#include <gui/BufferSlot.h> 22 23#include <utils/Condition.h> 24#include <utils/Mutex.h> 25#include <utils/RefBase.h> 26#include <utils/String8.h> 27#include <utils/StrongPointer.h> 28#include <utils/Trace.h> 29#include <utils/Vector.h> 30 31#define BQ_LOGV(x, ...) ALOGV("[%s] "x, mConsumerName.string(), ##__VA_ARGS__) 32#define BQ_LOGD(x, ...) ALOGD("[%s] "x, mConsumerName.string(), ##__VA_ARGS__) 33#define BQ_LOGI(x, ...) ALOGI("[%s] "x, mConsumerName.string(), ##__VA_ARGS__) 34#define BQ_LOGW(x, ...) ALOGW("[%s] "x, mConsumerName.string(), ##__VA_ARGS__) 35#define BQ_LOGE(x, ...) ALOGE("[%s] "x, mConsumerName.string(), ##__VA_ARGS__) 36 37#define ATRACE_BUFFER_INDEX(index) \ 38 if (ATRACE_ENABLED()) { \ 39 char ___traceBuf[1024]; \ 40 snprintf(___traceBuf, 1024, "%s: %d", \ 41 mCore->mConsumerName.string(), (index)); \ 42 android::ScopedTrace ___bufTracer(ATRACE_TAG, ___traceBuf); \ 43 } 44 45namespace android { 46 47class BufferItem; 48class IBinder; 49class IConsumerListener; 50class IGraphicBufferAlloc; 51 52class BufferQueueCore : public virtual RefBase { 53 54 friend class BufferQueueProducer; 55 friend class BufferQueueConsumer; 56 57public: 58 // Used as a placeholder slot number when the value isn't pointing to an 59 // existing buffer. 60 enum { INVALID_BUFFER_SLOT = -1 }; // TODO: Extract from IGBC::BufferItem 61 62 // We reserve two slots in order to guarantee that the producer and 63 // consumer can run asynchronously. 64 enum { MAX_MAX_ACQUIRED_BUFFERS = BufferQueueDefs::NUM_BUFFER_SLOTS - 2 }; 65 66 // The default API number used to indicate that no producer is connected 67 enum { NO_CONNECTED_API = 0 }; 68 69 typedef Vector<BufferItem> Fifo; 70 71 // BufferQueueCore manages a pool of gralloc memory slots to be used by 72 // producers and consumers. allocator is used to allocate all the needed 73 // gralloc buffers. 74 BufferQueueCore(const sp<IGraphicBufferAlloc>& allocator = NULL); 75 virtual ~BufferQueueCore(); 76 77private: 78 // Dump our state in a string 79 void dump(String8& result, const char* prefix) const; 80 81 // getMinUndequeuedBufferCountLocked returns the minimum number of buffers 82 // that must remain in a state other than DEQUEUED. The async parameter 83 // tells whether we're in asynchronous mode. 84 int getMinUndequeuedBufferCountLocked(bool async) const; 85 86 // getMinMaxBufferCountLocked returns the minimum number of buffers allowed 87 // given the current BufferQueue state. The async parameter tells whether 88 // we're in asynchonous mode. 89 int getMinMaxBufferCountLocked(bool async) const; 90 91 // getMaxBufferCountLocked returns the maximum number of buffers that can be 92 // allocated at once. This value depends on the following member variables: 93 // 94 // mDequeueBufferCannotBlock 95 // mMaxAcquiredBufferCount 96 // mDefaultMaxBufferCount 97 // mOverrideMaxBufferCount 98 // async parameter 99 // 100 // Any time one of these member variables is changed while a producer is 101 // connected, mDequeueCondition must be broadcast. 102 int getMaxBufferCountLocked(bool async) const; 103 104 // setDefaultMaxBufferCountLocked sets the maximum number of buffer slots 105 // that will be used if the producer does not override the buffer slot 106 // count. The count must be between 2 and NUM_BUFFER_SLOTS, inclusive. The 107 // initial default is 2. 108 status_t setDefaultMaxBufferCountLocked(int count); 109 110 // freeBufferLocked frees the GraphicBuffer and sync resources for the 111 // given slot. 112 void freeBufferLocked(int slot); 113 114 // freeAllBuffersLocked frees the GraphicBuffer and sync resources for 115 // all slots. 116 void freeAllBuffersLocked(); 117 118 // stillTracking returns true iff the buffer item is still being tracked 119 // in one of the slots. 120 bool stillTracking(const BufferItem* item) const; 121 122 // mAllocator is the connection to SurfaceFlinger that is used to allocate 123 // new GraphicBuffer objects. 124 sp<IGraphicBufferAlloc> mAllocator; 125 126 // mMutex is the mutex used to prevent concurrent access to the member 127 // variables of BufferQueueCore objects. It must be locked whenever any 128 // member variable is accessed. 129 mutable Mutex mMutex; 130 131 // mIsAbandoned indicates that the BufferQueue will no longer be used to 132 // consume image buffers pushed to it using the IGraphicBufferProducer 133 // interface. It is initialized to false, and set to true in the 134 // consumerDisconnect method. A BufferQueue that is abandoned will return 135 // the NO_INIT error from all IGraphicBufferProducer methods capable of 136 // returning an error. 137 bool mIsAbandoned; 138 139 // mConsumerControlledByApp indicates whether the connected consumer is 140 // controlled by the application. 141 bool mConsumerControlledByApp; 142 143 // mConsumerName is a string used to identify the BufferQueue in log 144 // messages. It is set by the IGraphicBufferConsumer::setConsumerName 145 // method. 146 String8 mConsumerName; 147 148 // mConsumerListener is used to notify the connected consumer of 149 // asynchronous events that it may wish to react to. It is initially 150 // set to NULL and is written by consumerConnect and consumerDisconnect. 151 sp<IConsumerListener> mConsumerListener; 152 153 // mConsumerUsageBits contains flags that the consumer wants for 154 // GraphicBuffers. 155 uint32_t mConsumerUsageBits; 156 157 // mConnectedApi indicates the producer API that is currently connected 158 // to this BufferQueue. It defaults to NO_CONNECTED_API, and gets updated 159 // by the connect and disconnect methods. 160 int mConnectedApi; 161 162 // mConnectedProducerToken is used to set a binder death notification on 163 // the producer. 164 sp<IBinder> mConnectedProducerToken; 165 166 // mSlots is an array of buffer slots that must be mirrored on the producer 167 // side. This allows buffer ownership to be transferred between the producer 168 // and consumer without sending a GraphicBuffer over Binder. The entire 169 // array is initialized to NULL at construction time, and buffers are 170 // allocated for a slot when requestBuffer is called with that slot's index. 171 BufferQueueDefs::SlotsType mSlots; 172 173 // mQueue is a FIFO of queued buffers used in synchronous mode. 174 Fifo mQueue; 175 176 // mOverrideMaxBufferCount is the limit on the number of buffers that will 177 // be allocated at one time. This value is set by the producer by calling 178 // setBufferCount. The default is 0, which means that the producer doesn't 179 // care about the number of buffers in the pool. In that case, 180 // mDefaultMaxBufferCount is used as the limit. 181 int mOverrideMaxBufferCount; 182 183 // mDequeueCondition is a condition variable used for dequeueBuffer in 184 // synchronous mode. 185 mutable Condition mDequeueCondition; 186 187 // mUseAsyncBuffer indicates whether an extra buffer is used in async mode 188 // to prevent dequeueBuffer from blocking. 189 bool mUseAsyncBuffer; 190 191 // mDequeueBufferCannotBlock indicates whether dequeueBuffer is allowed to 192 // block. This flag is set during connect when both the producer and 193 // consumer are controlled by the application. 194 bool mDequeueBufferCannotBlock; 195 196 // mDefaultBufferFormat can be set so it will override the buffer format 197 // when it isn't specified in dequeueBuffer. 198 uint32_t mDefaultBufferFormat; 199 200 // mDefaultWidth holds the default width of allocated buffers. It is used 201 // in dequeueBuffer if a width and height of 0 are specified. 202 int mDefaultWidth; 203 204 // mDefaultHeight holds the default height of allocated buffers. It is used 205 // in dequeueBuffer if a width and height of 0 are specified. 206 int mDefaultHeight; 207 208 // mDefaultMaxBufferCount is the default limit on the number of buffers that 209 // will be allocated at one time. This default limit is set by the consumer. 210 // The limit (as opposed to the default limit) may be overriden by the 211 // producer. 212 int mDefaultMaxBufferCount; 213 214 // mMaxAcquiredBufferCount is the number of buffers that the consumer may 215 // acquire at one time. It defaults to 1, and can be changed by the consumer 216 // via setMaxAcquiredBufferCount, but this may only be done while no 217 // producer is connected to the BufferQueue. This value is used to derive 218 // the value returned for the MIN_UNDEQUEUED_BUFFERS query to the producer. 219 int mMaxAcquiredBufferCount; 220 221 // mBufferHasBeenQueued is true once a buffer has been queued. It is reset 222 // when something causes all buffers to be freed (e.g., changing the buffer 223 // count). 224 bool mBufferHasBeenQueued; 225 226 // mFrameCounter is the free running counter, incremented on every 227 // successful queueBuffer call and buffer allocation. 228 uint64_t mFrameCounter; 229 230 // mTransformHint is used to optimize for screen rotations. 231 uint32_t mTransformHint; 232 233}; // class BufferQueueCore 234 235} // namespace android 236 237#endif 238