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 
27 namespace android {
28 
29 class BufferItem;
30 class FrameEventHistoryDelta;
31 struct 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 
38 class ConsumerListener : public virtual RefBase {
39 public:
ConsumerListener()40     ConsumerListener() {}
41     virtual ~ConsumerListener();
42 
43     // onDisconnect is called when a producer disconnects from the BufferQueue.
onDisconnect()44     virtual void onDisconnect() {} /* Asynchronous */
45 
46     // onFrameDequeued is called when a call to the BufferQueueProducer::dequeueBuffer successfully
47     // returns a slot from the BufferQueue.
onFrameDequeued(const uint64_t)48     virtual void onFrameDequeued(const uint64_t) {}
49 
50     // onFrameCancelled is called when the client calls cancelBuffer, thereby releasing the slot
51     // back to the BufferQueue.
onFrameCancelled(const uint64_t)52     virtual void onFrameCancelled(const uint64_t) {}
53 
54     // onFrameDetached is called after a successful detachBuffer() call while in asynchronous mode.
onFrameDetached(const uint64_t)55     virtual void onFrameDetached(const uint64_t) {}
56 
57     // onFrameAvailable is called from queueBuffer each time an additional frame becomes available
58     // for consumption. This means that frames that are queued while in asynchronous mode only
59     // trigger the callback if no previous frames are pending. Frames queued while in synchronous
60     // mode always trigger the callback. The item passed to the callback will contain all of the
61     // information about the queued frame except for its GraphicBuffer pointer, which will always be
62     // null (except if the consumer is SurfaceFlinger).
63     //
64     // This is called without any lock held and can be called concurrently by multiple threads.
65     virtual void onFrameAvailable(const BufferItem& item) = 0; /* Asynchronous */
66 
67     // onFrameReplaced is called from queueBuffer if the frame being queued is replacing an existing
68     // slot in the queue. Any call to queueBuffer that doesn't call onFrameAvailable will call this
69     // callback instead. The item passed to the callback will contain all of the information about
70     // the queued frame except for its GraphicBuffer pointer, which will always be null.
71     //
72     // This is called without any lock held and can be called concurrently by multiple threads.
onFrameReplaced(const BufferItem &)73     virtual void onFrameReplaced(const BufferItem& /* item */) {} /* Asynchronous */
74 
75     // onBuffersReleased is called to notify the buffer consumer that the BufferQueue has released
76     // its references to one or more GraphicBuffers contained in its slots. The buffer consumer
77     // should then call BufferQueue::getReleasedBuffers to retrieve the list of buffers.
78     //
79     // This is called without any lock held and can be called concurrently by multiple threads.
80     virtual void onBuffersReleased() = 0; /* Asynchronous */
81 
82     // onSidebandStreamChanged is called to notify the buffer consumer that the BufferQueue's
83     // sideband buffer stream has changed. This is called when a stream is first attached and when
84     // it is either detached or replaced by a different stream.
85     virtual void onSidebandStreamChanged() = 0; /* Asynchronous */
86 
87     // Notifies the consumer of any new producer-side timestamps and returns the combined frame
88     // history that hasn't already been retrieved.
89     //
90     // WARNING: This method can only be called when the BufferQueue is in the consumer's process.
addAndGetFrameTimestamps(const NewFrameEventsEntry *,FrameEventHistoryDelta *)91     virtual void addAndGetFrameTimestamps(const NewFrameEventsEntry* /*newTimestamps*/,
92                                           FrameEventHistoryDelta* /*outDelta*/) {}
93 };
94 
95 #ifndef NO_BINDER
96 class IConsumerListener : public ConsumerListener, public IInterface {
97 public:
98     DECLARE_META_INTERFACE(ConsumerListener)
99 };
100 
101 class BnConsumerListener : public SafeBnInterface<IConsumerListener> {
102 public:
BnConsumerListener()103     BnConsumerListener() : SafeBnInterface<IConsumerListener>("BnConsumerListener") {}
104 
105     status_t onTransact(uint32_t code, const Parcel& data, Parcel* reply,
106                         uint32_t flags = 0) override;
107 };
108 
109 #else
110 class IConsumerListener : public ConsumerListener {
111 };
112 class BnConsumerListener : public IConsumerListener {
113 };
114 #endif
115 
116 } // namespace android
117