1 /* 2 * Copyright (C) 2012 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_BUFFERITEMCONSUMER_H 18 #define ANDROID_GUI_BUFFERITEMCONSUMER_H 19 20 #include <gui/ConsumerBase.h> 21 #include <gui/BufferQueue.h> 22 23 #define ANDROID_GRAPHICS_BUFFERITEMCONSUMER_JNI_ID "mBufferItemConsumer" 24 25 namespace android { 26 27 class String8; 28 29 /** 30 * BufferItemConsumer is a BufferQueue consumer endpoint that allows clients 31 * access to the whole BufferItem entry from BufferQueue. Multiple buffers may 32 * be acquired at once, to be used concurrently by the client. This consumer can 33 * operate either in synchronous or asynchronous mode. 34 */ 35 class BufferItemConsumer: public ConsumerBase 36 { 37 public: 38 typedef ConsumerBase::FrameAvailableListener FrameAvailableListener; 39 40 struct BufferFreedListener : public virtual RefBase { 41 virtual void onBufferFreed(const wp<GraphicBuffer>& graphicBuffer) = 0; 42 }; 43 44 enum { DEFAULT_MAX_BUFFERS = -1 }; 45 enum { INVALID_BUFFER_SLOT = BufferQueue::INVALID_BUFFER_SLOT }; 46 enum { NO_BUFFER_AVAILABLE = BufferQueue::NO_BUFFER_AVAILABLE }; 47 48 // Create a new buffer item consumer. The consumerUsage parameter determines 49 // the consumer usage flags passed to the graphics allocator. The 50 // bufferCount parameter specifies how many buffers can be locked for user 51 // access at the same time. 52 // controlledByApp tells whether this consumer is controlled by the 53 // application. 54 BufferItemConsumer(const sp<IGraphicBufferConsumer>& consumer, 55 uint64_t consumerUsage, int bufferCount = DEFAULT_MAX_BUFFERS, 56 bool controlledByApp = false); 57 58 ~BufferItemConsumer() override; 59 60 // setBufferFreedListener sets the listener object that will be notified 61 // when an old buffer is being freed. 62 void setBufferFreedListener(const wp<BufferFreedListener>& listener); 63 64 // Gets the next graphics buffer from the producer, filling out the 65 // passed-in BufferItem structure. Returns NO_BUFFER_AVAILABLE if the queue 66 // of buffers is empty, and INVALID_OPERATION if the maximum number of 67 // buffers is already acquired. 68 // 69 // Only a fixed number of buffers can be acquired at a time, determined by 70 // the construction-time bufferCount parameter. If INVALID_OPERATION is 71 // returned by acquireBuffer, then old buffers must be returned to the 72 // queue by calling releaseBuffer before more buffers can be acquired. 73 // 74 // If waitForFence is true, and the acquired BufferItem has a valid fence object, 75 // acquireBuffer will wait on the fence with no timeout before returning. 76 status_t acquireBuffer(BufferItem* item, nsecs_t presentWhen, 77 bool waitForFence = true); 78 79 // Returns an acquired buffer to the queue, allowing it to be reused. Since 80 // only a fixed number of buffers may be acquired at a time, old buffers 81 // must be released by calling releaseBuffer to ensure new buffers can be 82 // acquired by acquireBuffer. Once a BufferItem is released, the caller must 83 // not access any members of the BufferItem, and should immediately remove 84 // all of its references to the BufferItem itself. 85 status_t releaseBuffer(const BufferItem &item, 86 const sp<Fence>& releaseFence = Fence::NO_FENCE); 87 88 private: 89 void freeBufferLocked(int slotIndex) override; 90 91 // mBufferFreedListener is the listener object that will be called when 92 // an old buffer is being freed. If it is not NULL it will be called from 93 // freeBufferLocked. 94 wp<BufferFreedListener> mBufferFreedListener; 95 }; 96 97 } // namespace android 98 99 #endif // ANDROID_GUI_CPUCONSUMER_H 100