BufferItemConsumer.h revision fe50d2a0a13116238d5321e16c06e6ed533618dc 
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
22#include <ui/GraphicBuffer.h>
23
24#include <utils/String8.h>
25#include <utils/Vector.h>
26#include <utils/threads.h>
27
28#define ANDROID_GRAPHICS_BUFFERITEMCONSUMER_JNI_ID "mBufferItemConsumer"
29
30namespace android {
31
32class BufferQueue;
33
34/**
35 * BufferItemConsumer is a BufferQueue consumer endpoint that allows clients
36 * access to the whole BufferItem entry from BufferQueue. Multiple buffers may
37 * be acquired at once, to be used concurrently by the client. This consumer can
38 * operate either in synchronous or asynchronous mode.
39 */
40class BufferItemConsumer: public ConsumerBase
41{
42  public:
43    typedef ConsumerBase::FrameAvailableListener FrameAvailableListener;
44
45    typedef BufferQueue::BufferItem BufferItem;
46
47    enum { DEFAULT_MAX_BUFFERS = -1 };
48    enum { INVALID_BUFFER_SLOT = BufferQueue::INVALID_BUFFER_SLOT };
49    enum { NO_BUFFER_AVAILABLE = BufferQueue::NO_BUFFER_AVAILABLE };
50
51    // Create a new buffer item consumer. The consumerUsage parameter determines
52    // the consumer usage flags passed to the graphics allocator. The
53    // bufferCount parameter specifies how many buffers can be locked for user
54    // access at the same time.
55    // controlledByApp tells whether this consumer is controlled by the
56    // application.
57    BufferItemConsumer(const sp<IGraphicBufferConsumer>& consumer,
58            uint32_t consumerUsage, int bufferCount = DEFAULT_MAX_BUFFERS,
59            bool controlledByApp = false);
60
61    virtual ~BufferItemConsumer();
62
63    // set the name of the BufferItemConsumer that will be used to identify it in
64    // log messages.
65    void setName(const String8& name);
66
67    // Gets the next graphics buffer from the producer, filling out the
68    // passed-in BufferItem structure. Returns NO_BUFFER_AVAILABLE if the queue
69    // of buffers is empty, and INVALID_OPERATION if the maximum number of
70    // buffers is already acquired.
71    //
72    // Only a fixed number of buffers can be acquired at a time, determined by
73    // the construction-time bufferCount parameter. If INVALID_OPERATION is
74    // returned by acquireBuffer, then old buffers must be returned to the
75    // queue by calling releaseBuffer before more buffers can be acquired.
76    //
77    // If waitForFence is true, and the acquired BufferItem has a valid fence object,
78    // acquireBuffer will wait on the fence with no timeout before returning.
79    status_t acquireBuffer(BufferItem *item, nsecs_t presentWhen,
80        bool waitForFence = true);
81
82    // Returns an acquired buffer to the queue, allowing it to be reused. Since
83    // only a fixed number of buffers may be acquired at a time, old buffers
84    // must be released by calling releaseBuffer to ensure new buffers can be
85    // acquired by acquireBuffer. Once a BufferItem is released, the caller must
86    // not access any members of the BufferItem, and should immediately remove
87    // all of its references to the BufferItem itself.
88    status_t releaseBuffer(const BufferItem &item,
89            const sp<Fence>& releaseFence = Fence::NO_FENCE);
90
91    // setDefaultBufferSize is used to set the size of buffers returned by
92    // requestBuffers when a with and height of zero is requested.
93    status_t setDefaultBufferSize(uint32_t w, uint32_t h);
94
95    // setDefaultBufferFormat allows the BufferQueue to create
96    // GraphicBuffers of a defaultFormat if no format is specified
97    // in dequeueBuffer
98    status_t setDefaultBufferFormat(uint32_t defaultFormat);
99};
100
101} // namespace android
102
103#endif // ANDROID_GUI_CPUCONSUMER_H
104