1/*
2 * Copyright (C) 2013 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#pragma once
18
19#include <binder/IInterface.h>
20#include <binder/SafeInterface.h>
21
22#include <utils/Errors.h>
23#include <utils/RefBase.h>
24
25#include <cstdint>
26
27namespace android {
28
29class BufferItem;
30class FrameEventHistoryDelta;
31struct NewFrameEventsEntry;
32
33// ConsumerListener is the interface through which the BufferQueue notifies the consumer of events
34// that the consumer may wish to react to. Because the consumer will generally have a mutex that is
35// locked during calls from the consumer to the BufferQueue, these calls from the BufferQueue to the
36// consumer *MUST* be called only when the BufferQueue mutex is NOT locked.
37
38class ConsumerListener : public virtual RefBase {
39public:
40    ConsumerListener() {}
41    virtual ~ConsumerListener();
42
43    // onDisconnect is called when a producer disconnects from the BufferQueue.
44    virtual void onDisconnect() {} /* Asynchronous */
45
46    // onFrameAvailable is called from queueBuffer each time an additional frame becomes available
47    // for consumption. This means that frames that are queued while in asynchronous mode only
48    // trigger the callback if no previous frames are pending. Frames queued while in synchronous
49    // mode always trigger the callback. The item passed to the callback will contain all of the
50    // information about the queued frame except for its GraphicBuffer pointer, which will always be
51    // null (except if the consumer is SurfaceFlinger).
52    //
53    // This is called without any lock held and can be called concurrently by multiple threads.
54    virtual void onFrameAvailable(const BufferItem& item) = 0; /* Asynchronous */
55
56    // onFrameReplaced is called from queueBuffer if the frame being queued is replacing an existing
57    // slot in the queue. Any call to queueBuffer that doesn't call onFrameAvailable will call this
58    // callback instead. The item passed to the callback will contain all of the information about
59    // the queued frame except for its GraphicBuffer pointer, which will always be null.
60    //
61    // This is called without any lock held and can be called concurrently by multiple threads.
62    virtual void onFrameReplaced(const BufferItem& /* item */) {} /* Asynchronous */
63
64    // onBuffersReleased is called to notify the buffer consumer that the BufferQueue has released
65    // its references to one or more GraphicBuffers contained in its slots. The buffer consumer
66    // should then call BufferQueue::getReleasedBuffers to retrieve the list of buffers.
67    //
68    // This is called without any lock held and can be called concurrently by multiple threads.
69    virtual void onBuffersReleased() = 0; /* Asynchronous */
70
71    // onSidebandStreamChanged is called to notify the buffer consumer that the BufferQueue's
72    // sideband buffer stream has changed. This is called when a stream is first attached and when
73    // it is either detached or replaced by a different stream.
74    virtual void onSidebandStreamChanged() = 0; /* Asynchronous */
75
76    // Notifies the consumer of any new producer-side timestamps and returns the combined frame
77    // history that hasn't already been retrieved.
78    //
79    // WARNING: This method can only be called when the BufferQueue is in the consumer's process.
80    virtual void addAndGetFrameTimestamps(const NewFrameEventsEntry* /*newTimestamps*/,
81                                          FrameEventHistoryDelta* /*outDelta*/) {}
82};
83
84class IConsumerListener : public ConsumerListener, public IInterface {
85public:
86    DECLARE_META_INTERFACE(ConsumerListener)
87};
88
89class BnConsumerListener : public SafeBnInterface<IConsumerListener> {
90public:
91    BnConsumerListener() : SafeBnInterface<IConsumerListener>("BnConsumerListener") {}
92
93    status_t onTransact(uint32_t code, const Parcel& data, Parcel* reply,
94                        uint32_t flags = 0) override;
95};
96
97} // namespace android
98