1 /* 2 * Copyright (C) 2010 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_CONSUMERBASE_H 18 #define ANDROID_GUI_CONSUMERBASE_H 19 20 #include <gui/BufferQueue.h> 21 22 #include <ui/GraphicBuffer.h> 23 24 #include <utils/String8.h> 25 #include <utils/Vector.h> 26 #include <utils/threads.h> 27 #include <gui/IConsumerListener.h> 28 29 namespace android { 30 // ---------------------------------------------------------------------------- 31 32 class String8; 33 34 // ConsumerBase is a base class for BufferQueue consumer end-points. It 35 // handles common tasks like management of the connection to the BufferQueue 36 // and the buffer pool. 37 class ConsumerBase : public virtual RefBase, 38 protected ConsumerListener { 39 public: 40 struct FrameAvailableListener : public virtual RefBase { 41 // onFrameAvailable() is called each time an additional frame becomes 42 // available for consumption. This means that frames that are queued 43 // while in asynchronous mode only trigger the callback if no previous 44 // frames are pending. Frames queued while in synchronous mode always 45 // trigger the callback. 46 // 47 // This is called without any lock held and can be called concurrently 48 // by multiple threads. 49 virtual void onFrameAvailable(const BufferItem& item) = 0; 50 }; 51 52 virtual ~ConsumerBase(); 53 54 // abandon frees all the buffers and puts the ConsumerBase into the 55 // 'abandoned' state. Once put in this state the ConsumerBase can never 56 // leave it. When in the 'abandoned' state, all methods of the 57 // IGraphicBufferProducer interface will fail with the NO_INIT error. 58 // 59 // Note that while calling this method causes all the buffers to be freed 60 // from the perspective of the the ConsumerBase, if there are additional 61 // references on the buffers (e.g. if a buffer is referenced by a client 62 // or by OpenGL ES as a texture) then those buffer will remain allocated. 63 void abandon(); 64 65 // set the name of the ConsumerBase that will be used to identify it in 66 // log messages. 67 void setName(const String8& name); 68 69 // dump writes the current state to a string. Child classes should add 70 // their state to the dump by overriding the dumpLocked method, which is 71 // called by these methods after locking the mutex. 72 void dump(String8& result) const; 73 void dump(String8& result, const char* prefix) const; 74 75 // setFrameAvailableListener sets the listener object that will be notified 76 // when a new frame becomes available. 77 void setFrameAvailableListener(const wp<FrameAvailableListener>& listener); 78 79 private: 80 ConsumerBase(const ConsumerBase&); 81 void operator=(const ConsumerBase&); 82 83 protected: 84 // ConsumerBase constructs a new ConsumerBase object to consume image 85 // buffers from the given IGraphicBufferConsumer. 86 // The controlledByApp flag indicates that this consumer is under the application's 87 // control. 88 ConsumerBase(const sp<IGraphicBufferConsumer>& consumer, bool controlledByApp = false); 89 90 // onLastStrongRef gets called by RefBase just before the dtor of the most 91 // derived class. It is used to clean up the buffers so that ConsumerBase 92 // can coordinate the clean-up by calling into virtual methods implemented 93 // by the derived classes. This would not be possible from the 94 // ConsuemrBase dtor because by the time that gets called the derived 95 // classes have already been destructed. 96 // 97 // This methods should not need to be overridden by derived classes, but 98 // if they are overridden the ConsumerBase implementation must be called 99 // from the derived class. 100 virtual void onLastStrongRef(const void* id); 101 102 // Implementation of the IConsumerListener interface. These 103 // calls are used to notify the ConsumerBase of asynchronous events in the 104 // BufferQueue. The onFrameAvailable and onBuffersReleased methods should 105 // not need to be overridden by derived classes, but if they are overridden 106 // the ConsumerBase implementation must be called from the derived class. 107 // The ConsumerBase version of onSidebandStreamChanged does nothing and can 108 // be overriden by derived classes if they want the notification. 109 virtual void onFrameAvailable(const BufferItem& item); 110 virtual void onBuffersReleased(); 111 virtual void onSidebandStreamChanged(); 112 113 // freeBufferLocked frees up the given buffer slot. If the slot has been 114 // initialized this will release the reference to the GraphicBuffer in that 115 // slot. Otherwise it has no effect. 116 // 117 // Derived classes should override this method to clean up any state they 118 // keep per slot. If it is overridden, the derived class's implementation 119 // must call ConsumerBase::freeBufferLocked. 120 // 121 // This method must be called with mMutex locked. 122 virtual void freeBufferLocked(int slotIndex); 123 124 // abandonLocked puts the BufferQueue into the abandoned state, causing 125 // all future operations on it to fail. This method rather than the public 126 // abandon method should be overridden by child classes to add abandon- 127 // time behavior. 128 // 129 // Derived classes should override this method to clean up any object 130 // state they keep (as opposed to per-slot state). If it is overridden, 131 // the derived class's implementation must call ConsumerBase::abandonLocked. 132 // 133 // This method must be called with mMutex locked. 134 virtual void abandonLocked(); 135 136 // dumpLocked dumps the current state of the ConsumerBase object to the 137 // result string. Each line is prefixed with the string pointed to by the 138 // prefix argument. The buffer argument points to a buffer that may be 139 // used for intermediate formatting data, and the size of that buffer is 140 // indicated by the size argument. 141 // 142 // Derived classes should override this method to dump their internal 143 // state. If this method is overridden the derived class's implementation 144 // should call ConsumerBase::dumpLocked. 145 // 146 // This method must be called with mMutex locked. 147 virtual void dumpLocked(String8& result, const char* prefix) const; 148 149 // acquireBufferLocked fetches the next buffer from the BufferQueue and 150 // updates the buffer slot for the buffer returned. 151 // 152 // Derived classes should override this method to perform any 153 // initialization that must take place the first time a buffer is assigned 154 // to a slot. If it is overridden the derived class's implementation must 155 // call ConsumerBase::acquireBufferLocked. 156 virtual status_t acquireBufferLocked(IGraphicBufferConsumer::BufferItem *item, 157 nsecs_t presentWhen); 158 159 // releaseBufferLocked relinquishes control over a buffer, returning that 160 // control to the BufferQueue. 161 // 162 // Derived classes should override this method to perform any cleanup that 163 // must take place when a buffer is released back to the BufferQueue. If 164 // it is overridden the derived class's implementation must call 165 // ConsumerBase::releaseBufferLocked.e 166 virtual status_t releaseBufferLocked(int slot, 167 const sp<GraphicBuffer> graphicBuffer, 168 EGLDisplay display, EGLSyncKHR eglFence); 169 170 // returns true iff the slot still has the graphicBuffer in it. 171 bool stillTracking(int slot, const sp<GraphicBuffer> graphicBuffer); 172 173 // addReleaseFence* adds the sync points associated with a fence to the set 174 // of sync points that must be reached before the buffer in the given slot 175 // may be used after the slot has been released. This should be called by 176 // derived classes each time some asynchronous work is kicked off that 177 // references the buffer. 178 status_t addReleaseFence(int slot, 179 const sp<GraphicBuffer> graphicBuffer, const sp<Fence>& fence); 180 status_t addReleaseFenceLocked(int slot, 181 const sp<GraphicBuffer> graphicBuffer, const sp<Fence>& fence); 182 183 // Slot contains the information and object references that 184 // ConsumerBase maintains about a BufferQueue buffer slot. 185 struct Slot { 186 // mGraphicBuffer is the Gralloc buffer store in the slot or NULL if 187 // no Gralloc buffer is in the slot. 188 sp<GraphicBuffer> mGraphicBuffer; 189 190 // mFence is a fence which will signal when the buffer associated with 191 // this buffer slot is no longer being used by the consumer and can be 192 // overwritten. The buffer can be dequeued before the fence signals; 193 // the producer is responsible for delaying writes until it signals. 194 sp<Fence> mFence; 195 196 // the frame number of the last acquired frame for this slot 197 uint64_t mFrameNumber; 198 }; 199 200 // mSlots stores the buffers that have been allocated by the BufferQueue 201 // for each buffer slot. It is initialized to null pointers, and gets 202 // filled in with the result of BufferQueue::acquire when the 203 // client dequeues a buffer from a 204 // slot that has not yet been used. The buffer allocated to a slot will also 205 // be replaced if the requested buffer usage or geometry differs from that 206 // of the buffer allocated to a slot. 207 Slot mSlots[BufferQueue::NUM_BUFFER_SLOTS]; 208 209 // mAbandoned indicates that the BufferQueue will no longer be used to 210 // consume images buffers pushed to it using the IGraphicBufferProducer 211 // interface. It is initialized to false, and set to true in the abandon 212 // method. A BufferQueue that has been abandoned will return the NO_INIT 213 // error from all IConsumerBase methods capable of returning an error. 214 bool mAbandoned; 215 216 // mName is a string used to identify the ConsumerBase in log messages. 217 // It can be set by the setName method. 218 String8 mName; 219 220 // mFrameAvailableListener is the listener object that will be called when a 221 // new frame becomes available. If it is not NULL it will be called from 222 // queueBuffer. 223 wp<FrameAvailableListener> mFrameAvailableListener; 224 225 // The ConsumerBase has-a BufferQueue and is responsible for creating this object 226 // if none is supplied 227 sp<IGraphicBufferConsumer> mConsumer; 228 229 // mMutex is the mutex used to prevent concurrent access to the member 230 // variables of ConsumerBase objects. It must be locked whenever the 231 // member variables are accessed or when any of the *Locked methods are 232 // called. 233 // 234 // This mutex is intended to be locked by derived classes. 235 mutable Mutex mMutex; 236 }; 237 238 // ---------------------------------------------------------------------------- 239 }; // namespace android 240 241 #endif // ANDROID_GUI_CONSUMERBASE_H 242
