xref: /aosp_15_r20/frameworks/native/libs/gui/include/gui/BufferItemConsumer.h (revision 38e8c45f13ce32b0dcecb25141ffecaf386fa17f)
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 <com_android_graphics_libgui_flags.h>
21 #include <gui/BufferQueue.h>
22 #include <gui/ConsumerBase.h>
23 
24 #define ANDROID_GRAPHICS_BUFFERITEMCONSUMER_JNI_ID "mBufferItemConsumer"
25 
26 namespace android {
27 
28 class GraphicBuffer;
29 class String8;
30 
31 /**
32  * BufferItemConsumer is a BufferQueue consumer endpoint that allows clients
33  * access to the whole BufferItem entry from BufferQueue. Multiple buffers may
34  * be acquired at once, to be used concurrently by the client. This consumer can
35  * operate either in synchronous or asynchronous mode.
36  */
37 class BufferItemConsumer: public ConsumerBase
38 {
39   public:
40     typedef ConsumerBase::FrameAvailableListener FrameAvailableListener;
41 
42     struct BufferFreedListener : public virtual RefBase {
43         virtual void onBufferFreed(const wp<GraphicBuffer>& graphicBuffer) = 0;
44     };
45 
46     enum { DEFAULT_MAX_BUFFERS = -1 };
47     enum { INVALID_BUFFER_SLOT = BufferQueue::INVALID_BUFFER_SLOT };
48     enum { NO_BUFFER_AVAILABLE = BufferQueue::NO_BUFFER_AVAILABLE };
49 
50     // Create a new buffer item consumer. The consumerUsage parameter determines
51     // the consumer usage flags passed to the graphics allocator. The
52     // bufferCount parameter specifies how many buffers can be locked for user
53     // access at the same time.
54     // controlledByApp tells whether this consumer is controlled by the
55     // application.
56 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_CONSUMER_BASE_OWNS_BQ)
57     BufferItemConsumer(uint64_t consumerUsage, int bufferCount = DEFAULT_MAX_BUFFERS,
58                        bool controlledByApp = false, bool isConsumerSurfaceFlinger = false);
59     BufferItemConsumer(const sp<IGraphicBufferConsumer>& consumer, uint64_t consumerUsage,
60                        int bufferCount = DEFAULT_MAX_BUFFERS, bool controlledByApp = false)
61             __attribute((deprecated("Prefer ctors that create their own surface and consumer.")));
62 #else
63     BufferItemConsumer(const sp<IGraphicBufferConsumer>& consumer,
64             uint64_t consumerUsage, int bufferCount = DEFAULT_MAX_BUFFERS,
65             bool controlledByApp = false);
66 #endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_CONSUMER_BASE_OWNS_BQ)
67 
68     ~BufferItemConsumer() override;
69 
70     // setBufferFreedListener sets the listener object that will be notified
71     // when an old buffer is being freed.
72     void setBufferFreedListener(const wp<BufferFreedListener>& listener);
73 
74     // Gets the next graphics buffer from the producer, filling out the
75     // passed-in BufferItem structure. Returns NO_BUFFER_AVAILABLE if the queue
76     // of buffers is empty, and INVALID_OPERATION if the maximum number of
77     // buffers is already acquired.
78     //
79     // Only a fixed number of buffers can be acquired at a time, determined by
80     // the construction-time bufferCount parameter. If INVALID_OPERATION is
81     // returned by acquireBuffer, then old buffers must be returned to the
82     // queue by calling releaseBuffer before more buffers can be acquired.
83     //
84     // If waitForFence is true, and the acquired BufferItem has a valid fence object,
85     // acquireBuffer will wait on the fence with no timeout before returning.
86     status_t acquireBuffer(BufferItem* item, nsecs_t presentWhen,
87             bool waitForFence = true);
88 
89     // Returns an acquired buffer to the queue, allowing it to be reused. Since
90     // only a fixed number of buffers may be acquired at a time, old buffers
91     // must be released by calling releaseBuffer to ensure new buffers can be
92     // acquired by acquireBuffer. Once a BufferItem is released, the caller must
93     // not access any members of the BufferItem, and should immediately remove
94     // all of its references to the BufferItem itself.
95     status_t releaseBuffer(const BufferItem &item,
96             const sp<Fence>& releaseFence = Fence::NO_FENCE);
97 
98 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
99     status_t releaseBuffer(const sp<GraphicBuffer>& buffer,
100                            const sp<Fence>& releaseFence = Fence::NO_FENCE);
101 #endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
102 
103 protected:
104 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_CONSUMER_BASE_OWNS_BQ)
105     // This should only be used by BLASTBufferQueue:
106     BufferItemConsumer(const sp<IGraphicBufferProducer>& producer,
107                        const sp<IGraphicBufferConsumer>& consumer, uint64_t consumerUsage,
108                        int bufferCount = DEFAULT_MAX_BUFFERS, bool controlledByApp = false);
109 #endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_CONSUMER_BASE_OWNS_BQ)
110 
111 private:
112     void initialize(uint64_t consumerUsage, int bufferCount);
113 
114     status_t releaseBufferSlotLocked(int slotIndex, const sp<GraphicBuffer>& buffer,
115                                      const sp<Fence>& releaseFence);
116 
117     void freeBufferLocked(int slotIndex) override;
118 
119     // mBufferFreedListener is the listener object that will be called when
120     // an old buffer is being freed. If it is not NULL it will be called from
121     // freeBufferLocked.
122     wp<BufferFreedListener> mBufferFreedListener;
123 };
124 
125 } // namespace android
126 
127 #endif // ANDROID_GUI_CPUCONSUMER_H
128