path: root/hwc2/common/observers/SoftVsyncObserver.cpp (plain)
blob: 6347b8dcdfd7c4e93fe78ec2dbb9e793d514700e

1	/*
2	// Copyright (c) 2014 Intel Corporation
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	// This file is modified by Amlogic, Inc. 2017.01.17.
17	*/
18
19	#include <HwcTrace.h>
20	#include <SoftVsyncObserver.h>
21	#include <IDisplayDevice.h>
22
23	extern "C" int clock_nanosleep(clockid_t clock_id, int flags,
24	const struct timespec *request,
25	struct timespec *remain);
26
27
28	namespace android {
29	namespace amlogic {
30
31	SoftVsyncObserver::SoftVsyncObserver(IDisplayDevice& disp)
32	: mDisplayDevice(disp),
33	mEnabled(false),
34	mRefreshRate(60), // default 60 frames per second
35	mRefreshPeriod(0),
36	mLock(),
37	mCondition(),
38	mNextFakeVSync(0),
39	mExitThread(false),
40	mInitialized(false)
41	{
42	}
43
44	SoftVsyncObserver::~SoftVsyncObserver()
45	{
46	WARN_IF_NOT_DEINIT();
47	}
48
49	bool SoftVsyncObserver::initialize()
50	{
51	if (mInitialized) {
52	WTRACE("object has been initialized");
53	return true;
54	}
55
56	mExitThread = false;
57	mEnabled = false;
58	mRefreshRate = 60;
59	mRefreshPeriod = nsecs_t(1e9 / mRefreshRate);
60	mThread = new VsyncEventPollThread(this);
61	if (!mThread.get()) {
62	DEINIT_AND_RETURN_FALSE("failed to create vsync event poll thread.");
63	}
64	mThread->run("SoftVsyncObserver", PRIORITY_URGENT_DISPLAY);
65	mInitialized = true;
66	return true;
67	}
68
69	void SoftVsyncObserver::deinitialize()
70	{
71	if (mEnabled) {
72	WTRACE("soft vsync is still enabled");
73	control(false);
74	}
75
76	mExitThread = true;
77	mCondition.signal();
78
79	if (mThread.get()) {
80	mThread->requestExitAndWait();
81	mThread = NULL;
82	}
83	mInitialized = false;
84	}
85
86	void SoftVsyncObserver::setRefreshRate(int rate)
87	{
88	Mutex::Autolock _l(mLock);
89
90	if (rate < 1 || rate > 120) {
91	WTRACE("invalid refresh rate %d", rate);
92	} else if (mRefreshRate != rate) {
93	mRefreshRate = rate;
94	if (mEnabled) {
95	mRefreshPeriod = nsecs_t(1e9 / mRefreshRate);
96	mNextFakeVSync = systemTime(CLOCK_MONOTONIC) + mRefreshPeriod;
97	}
98	}
99	}
100
101	bool SoftVsyncObserver::control(bool enabled)
102	{
103	Mutex::Autolock _l(mLock);
104
105	if (enabled == mEnabled) {
106	WTRACE("vsync state %d is not changed", enabled);
107	return true;
108	}
109
110	if (enabled) {
111	mRefreshPeriod = nsecs_t(1e9 / mRefreshRate);
112	mNextFakeVSync = systemTime(CLOCK_MONOTONIC) + mRefreshPeriod;
113	}
114	mEnabled = enabled;
115	mCondition.signal();
116	return true;
117	}
118
119	bool SoftVsyncObserver::threadLoop()
120	{
121	{ // scope for lock
122	Mutex::Autolock _l(mLock);
123	while (!mEnabled) {
124	mCondition.wait(mLock);
125	if (mExitThread) {
126	ITRACE("exiting thread loop");
127	return false;
128	}
129	}
130	}
131
132
133	const nsecs_t period = mRefreshPeriod;
134	const nsecs_t now = systemTime(CLOCK_MONOTONIC);
135	nsecs_t next_vsync = mNextFakeVSync;
136	nsecs_t sleep = next_vsync - now;
137	if (sleep < 0) {
138	// we missed, find where the next vsync should be
139	sleep = (period - ((now - next_vsync) % period));
140	next_vsync = now + sleep;
141	}
142	mNextFakeVSync = next_vsync + period;
143
144	struct timespec spec;
145	spec.tv_sec = next_vsync / 1000000000;
146	spec.tv_nsec = next_vsync % 1000000000;
147
148	int err;
149	do {
150	err = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &spec, NULL);
151	} while (err < 0 && errno == EINTR);
152
153
154	if (err == 0) {
155	mDisplayDevice.onVsync(next_vsync);
156	}
157
158	return true;
159	}
160
161	} // namespace amlogic
162	} // namesapce android
163
164