/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef ANDROID_GUI_CONSUMERBASE_H #define ANDROID_GUI_CONSUMERBASE_H #include #include #include #include #include namespace android { // ---------------------------------------------------------------------------- class String8; // ConsumerBase is a base class for BufferQueue consumer end-points. It // handles common tasks like management of the connection to the BufferQueue // and the buffer pool. class ConsumerBase : public virtual RefBase, protected BufferQueue::ConsumerListener { public: struct FrameAvailableListener : public virtual RefBase { // onFrameAvailable() is called each time an additional frame becomes // available for consumption. This means that frames that are queued // while in asynchronous mode only trigger the callback if no previous // frames are pending. Frames queued while in synchronous mode always // trigger the callback. // // This is called without any lock held and can be called concurrently // by multiple threads. virtual void onFrameAvailable() = 0; }; virtual ~ConsumerBase(); // abandon frees all the buffers and puts the ConsumerBase into the // 'abandoned' state. Once put in this state the ConsumerBase can never // leave it. When in the 'abandoned' state, all methods of the // IGraphicBufferProducer interface will fail with the NO_INIT error. // // Note that while calling this method causes all the buffers to be freed // from the perspective of the the ConsumerBase, if there are additional // references on the buffers (e.g. if a buffer is referenced by a client // or by OpenGL ES as a texture) then those buffer will remain allocated. void abandon(); // set the name of the ConsumerBase that will be used to identify it in // log messages. void setName(const String8& name); // getBufferQueue returns the BufferQueue object to which this // ConsumerBase is connected. sp getBufferQueue() const; // dump writes the current state to a string. Child classes should add // their state to the dump by overriding the dumpLocked method, which is // called by these methods after locking the mutex. void dump(String8& result) const; void dump(String8& result, const char* prefix) const; // setFrameAvailableListener sets the listener object that will be notified // when a new frame becomes available. void setFrameAvailableListener(const wp& listener); private: ConsumerBase(const ConsumerBase&); void operator=(const ConsumerBase&); protected: // ConsumerBase constructs a new ConsumerBase object to consume image // buffers from the given BufferQueue. ConsumerBase(const sp &bufferQueue); // onLastStrongRef gets called by RefBase just before the dtor of the most // derived class. It is used to clean up the buffers so that ConsumerBase // can coordinate the clean-up by calling into virtual methods implemented // by the derived classes. This would not be possible from the // ConsuemrBase dtor because by the time that gets called the derived // classes have already been destructed. // // This methods should not need to be overridden by derived classes, but // if they are overridden the ConsumerBase implementation must be called // from the derived class. virtual void onLastStrongRef(const void* id); // Implementation of the BufferQueue::ConsumerListener interface. These // calls are used to notify the ConsumerBase of asynchronous events in the // BufferQueue. These methods should not need to be overridden by derived // classes, but if they are overridden the ConsumerBase implementation // must be called from the derived class. virtual void onFrameAvailable(); virtual void onBuffersReleased(); // freeBufferLocked frees up the given buffer slot. If the slot has been // initialized this will release the reference to the GraphicBuffer in that // slot. Otherwise it has no effect. // // Derived classes should override this method to clean up any state they // keep per slot. If it is overridden, the derived class's implementation // must call ConsumerBase::freeBufferLocked. // // This method must be called with mMutex locked. virtual void freeBufferLocked(int slotIndex); // abandonLocked puts the BufferQueue into the abandoned state, causing // all future operations on it to fail. This method rather than the public // abandon method should be overridden by child classes to add abandon- // time behavior. // // Derived classes should override this method to clean up any object // state they keep (as opposed to per-slot state). If it is overridden, // the derived class's implementation must call ConsumerBase::abandonLocked. // // This method must be called with mMutex locked. virtual void abandonLocked(); // dumpLocked dumps the current state of the ConsumerBase object to the // result string. Each line is prefixed with the string pointed to by the // prefix argument. The buffer argument points to a buffer that may be // used for intermediate formatting data, and the size of that buffer is // indicated by the size argument. // // Derived classes should override this method to dump their internal // state. If this method is overridden the derived class's implementation // should call ConsumerBase::dumpLocked. // // This method must be called with mMutex locked. virtual void dumpLocked(String8& result, const char* prefix) const; // acquireBufferLocked fetches the next buffer from the BufferQueue and // updates the buffer slot for the buffer returned. // // Derived classes should override this method to perform any // initialization that must take place the first time a buffer is assigned // to a slot. If it is overridden the derived class's implementation must // call ConsumerBase::acquireBufferLocked. virtual status_t acquireBufferLocked(BufferQueue::BufferItem *item, nsecs_t presentWhen); // releaseBufferLocked relinquishes control over a buffer, returning that // control to the BufferQueue. // // Derived classes should override this method to perform any cleanup that // must take place when a buffer is released back to the BufferQueue. If // it is overridden the derived class's implementation must call // ConsumerBase::releaseBufferLocked.e virtual status_t releaseBufferLocked(int slot, const sp graphicBuffer, EGLDisplay display, EGLSyncKHR eglFence); // returns true iff the slot still has the graphicBuffer in it. bool stillTracking(int slot, const sp graphicBuffer); // addReleaseFence* adds the sync points associated with a fence to the set // of sync points that must be reached before the buffer in the given slot // may be used after the slot has been released. This should be called by // derived classes each time some asynchronous work is kicked off that // references the buffer. status_t addReleaseFence(int slot, const sp graphicBuffer, const sp& fence); status_t addReleaseFenceLocked(int slot, const sp graphicBuffer, const sp& fence); // Slot contains the information and object references that // ConsumerBase maintains about a BufferQueue buffer slot. struct Slot { // mGraphicBuffer is the Gralloc buffer store in the slot or NULL if // no Gralloc buffer is in the slot. sp mGraphicBuffer; // mFence is a fence which will signal when the buffer associated with // this buffer slot is no longer being used by the consumer and can be // overwritten. The buffer can be dequeued before the fence signals; // the producer is responsible for delaying writes until it signals. sp mFence; // the frame number of the last acquired frame for this slot uint64_t mFrameNumber; }; // mSlots stores the buffers that have been allocated by the BufferQueue // for each buffer slot. It is initialized to null pointers, and gets // filled in with the result of BufferQueue::acquire when the // client dequeues a buffer from a // slot that has not yet been used. The buffer allocated to a slot will also // be replaced if the requested buffer usage or geometry differs from that // of the buffer allocated to a slot. Slot mSlots[BufferQueue::NUM_BUFFER_SLOTS]; // mAbandoned indicates that the BufferQueue will no longer be used to // consume images buffers pushed to it using the IGraphicBufferProducer // interface. It is initialized to false, and set to true in the abandon // method. A BufferQueue that has been abandoned will return the NO_INIT // error from all IConsumerBase methods capable of returning an error. bool mAbandoned; // mName is a string used to identify the ConsumerBase in log messages. // It can be set by the setName method. String8 mName; // mFrameAvailableListener is the listener object that will be called when a // new frame becomes available. If it is not NULL it will be called from // queueBuffer. wp mFrameAvailableListener; // The ConsumerBase has-a BufferQueue and is responsible for creating this object // if none is supplied sp mBufferQueue; // mMutex is the mutex used to prevent concurrent access to the member // variables of ConsumerBase objects. It must be locked whenever the // member variables are accessed or when any of the *Locked methods are // called. // // This mutex is intended to be locked by derived classes. mutable Mutex mMutex; }; // ---------------------------------------------------------------------------- }; // namespace android #endif // ANDROID_GUI_CONSUMERBASE_H