RenderThread.h revision a5dda645da738da7b4ae15e28fa7d93d3b04b94f 
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#ifndef RENDERTHREAD_H_
18#define RENDERTHREAD_H_
19
20#include "RenderTask.h"
21
22#include <memory>
23#include <set>
24
25#include <cutils/compiler.h>
26#include <utils/Looper.h>
27#include <utils/Mutex.h>
28#include <utils/Singleton.h>
29#include <utils/Thread.h>
30
31#include "TimeLord.h"
32
33namespace android {
34class DisplayEventReceiver;
35
36namespace uirenderer {
37namespace renderthread {
38
39class DispatchFrameCallbacks;
40
41class TaskQueue {
42public:
43    TaskQueue();
44
45    RenderTask* next();
46    void queue(RenderTask* task);
47    void queueAtFront(RenderTask* task);
48    RenderTask* peek();
49    void remove(RenderTask* task);
50
51private:
52    RenderTask* mHead;
53    RenderTask* mTail;
54};
55
56// Mimics android.view.Choreographer.FrameCallback
57class IFrameCallback {
58public:
59    virtual void doFrame() = 0;
60
61protected:
62    ~IFrameCallback() {}
63};
64
65class ANDROID_API RenderThread : public Thread, public Singleton<RenderThread> {
66public:
67    // RenderThread takes complete ownership of tasks that are queued
68    // and will delete them after they are run
69    ANDROID_API void queue(RenderTask* task);
70    ANDROID_API void queueAtFront(RenderTask* task);
71    void queueDelayed(RenderTask* task, int delayMs);
72    void remove(RenderTask* task);
73
74    // Mimics android.view.Choreographer
75    void postFrameCallback(IFrameCallback* callback);
76    void removeFrameCallback(IFrameCallback* callback);
77    // If the callback is currently registered, it will be pushed back until
78    // the next vsync. If it is not currently registered this does nothing.
79    void pushBackFrameCallback(IFrameCallback* callback);
80
81    TimeLord& timeLord() { return mTimeLord; }
82
83protected:
84    virtual bool threadLoop();
85
86private:
87    friend class Singleton<RenderThread>;
88    friend class DispatchFrameCallbacks;
89
90    RenderThread();
91    virtual ~RenderThread();
92
93    void initializeDisplayEventReceiver();
94    static int displayEventReceiverCallback(int fd, int events, void* data);
95    void drainDisplayEventQueue(bool skipCallbacks = false);
96    void dispatchFrameCallbacks();
97    void requestVsync();
98
99    // Returns the next task to be run. If this returns NULL nextWakeup is set
100    // to the time to requery for the nextTask to run. mNextWakeup is also
101    // set to this time
102    RenderTask* nextTask(nsecs_t* nextWakeup);
103
104    sp<Looper> mLooper;
105    Mutex mLock;
106
107    nsecs_t mNextWakeup;
108    TaskQueue mQueue;
109
110    DisplayEventReceiver* mDisplayEventReceiver;
111    bool mVsyncRequested;
112    std::set<IFrameCallback*> mFrameCallbacks;
113    // We defer the actual registration of these callbacks until
114    // both mQueue *and* mDisplayEventReceiver have been drained off all
115    // immediate events. This makes sure that we catch the next vsync, not
116    // the previous one
117    std::set<IFrameCallback*> mPendingRegistrationFrameCallbacks;
118    bool mFrameCallbackTaskPending;
119    DispatchFrameCallbacks* mFrameCallbackTask;
120
121    TimeLord mTimeLord;
122};
123
124} /* namespace renderthread */
125} /* namespace uirenderer */
126} /* namespace android */
127#endif /* RENDERTHREAD_H_ */
128