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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 
30 namespace android {
31 
32 /**
33  * BufferItemConsumer is a BufferQueue consumer endpoint that allows clients
34  * access to the whole BufferItem entry from BufferQueue. Multiple buffers may
35  * be acquired at once, to be used concurrently by the client. This consumer can
36  * operate either in synchronous or asynchronous mode.
37  */
38 class BufferItemConsumer: public ConsumerBase
39 {
40   public:
41     typedef ConsumerBase::FrameAvailableListener FrameAvailableListener;
42 
43     typedef BufferQueue::BufferItem BufferItem;
44 
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     BufferItemConsumer(uint32_t consumerUsage,
53             int bufferCount = BufferQueue::MIN_UNDEQUEUED_BUFFERS,
54             bool synchronousMode = false);
55 
56     virtual ~BufferItemConsumer();
57 
58     // set the name of the BufferItemConsumer that will be used to identify it in
59     // log messages.
60     void setName(const String8& name);
61 
62     // Gets the next graphics buffer from the producer, filling out the
63     // passed-in BufferItem structure. Returns NO_BUFFER_AVAILABLE if the queue
64     // of buffers is empty, and INVALID_OPERATION if the maximum number of
65     // buffers is already acquired.
66     //
67     // Only a fixed number of buffers can be acquired at a time, determined by
68     // the construction-time bufferCount parameter. If INVALID_OPERATION is
69     // returned by acquireBuffer, then old buffers must be returned to the
70     // queue by calling releaseBuffer before more buffers can be acquired.
71     //
72     // If waitForFence is true, and the acquired BufferItem has a valid fence object,
73     // acquireBuffer will wait on the fence with no timeout before returning.
74     status_t acquireBuffer(BufferItem *item, bool waitForFence = true);
75 
76     // Returns an acquired buffer to the queue, allowing it to be reused. Since
77     // only a fixed number of buffers may be acquired at a time, old buffers
78     // must be released by calling releaseBuffer to ensure new buffers can be
79     // acquired by acquireBuffer. Once a BufferItem is released, the caller must
80     // not access any members of the BufferItem, and should immediately remove
81     // all of its references to the BufferItem itself.
82     status_t releaseBuffer(const BufferItem &item,
83             const sp<Fence>& releaseFence = Fence::NO_FENCE);
84 
getProducerInterface()85     sp<IGraphicBufferProducer> getProducerInterface() const { return getBufferQueue(); }
86 
87     // setDefaultBufferSize is used to set the size of buffers returned by
88     // requestBuffers when a with and height of zero is requested.
89     status_t setDefaultBufferSize(uint32_t w, uint32_t h);
90 
91     // setDefaultBufferFormat allows the BufferQueue to create
92     // GraphicBuffers of a defaultFormat if no format is specified
93     // in dequeueBuffer
94     status_t setDefaultBufferFormat(uint32_t defaultFormat);
95 };
96 
97 } // namespace android
98 
99 #endif // ANDROID_GUI_CPUCONSUMER_H
100