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    enum { DEFAULT_MAX_BUFFERS = -1 };
46    enum { INVALID_BUFFER_SLOT = BufferQueue::INVALID_BUFFER_SLOT };
47    enum { NO_BUFFER_AVAILABLE = BufferQueue::NO_BUFFER_AVAILABLE };
48
49    // Create a new buffer item consumer. The consumerUsage parameter determines
50    // the consumer usage flags passed to the graphics allocator. The
51    // bufferCount parameter specifies how many buffers can be locked for user
52    // access at the same time.
53    // controlledByApp tells whether this consumer is controlled by the
54    // application.
55    BufferItemConsumer(const sp<IGraphicBufferConsumer>& consumer,
56            uint32_t consumerUsage, int bufferCount = DEFAULT_MAX_BUFFERS,
57            bool controlledByApp = false);
58
59    virtual ~BufferItemConsumer();
60
61    // set the name of the BufferItemConsumer that will be used to identify it in
62    // log messages.
63    void setName(const String8& name);
64
65    // Gets the next graphics buffer from the producer, filling out the
66    // passed-in BufferItem structure. Returns NO_BUFFER_AVAILABLE if the queue
67    // of buffers is empty, and INVALID_OPERATION if the maximum number of
68    // buffers is already acquired.
69    //
70    // Only a fixed number of buffers can be acquired at a time, determined by
71    // the construction-time bufferCount parameter. If INVALID_OPERATION is
72    // returned by acquireBuffer, then old buffers must be returned to the
73    // queue by calling releaseBuffer before more buffers can be acquired.
74    //
75    // If waitForFence is true, and the acquired BufferItem has a valid fence object,
76    // acquireBuffer will wait on the fence with no timeout before returning.
77    status_t acquireBuffer(BufferItem* item, nsecs_t presentWhen,
78            bool waitForFence = true);
79
80    // Returns an acquired buffer to the queue, allowing it to be reused. Since
81    // only a fixed number of buffers may be acquired at a time, old buffers
82    // must be released by calling releaseBuffer to ensure new buffers can be
83    // acquired by acquireBuffer. Once a BufferItem is released, the caller must
84    // not access any members of the BufferItem, and should immediately remove
85    // all of its references to the BufferItem itself.
86    status_t releaseBuffer(const BufferItem &item,
87            const sp<Fence>& releaseFence = Fence::NO_FENCE);
88
89};
90
91} // namespace android
92
93#endif // ANDROID_GUI_CPUCONSUMER_H
94