1 /*
2  * Copyright 2018 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 #define ATRACE_TAG ATRACE_TAG_GRAPHICS
18 
19 #include "DispSyncSource.h"
20 
21 #include <android-base/stringprintf.h>
22 #include <utils/Trace.h>
23 #include <mutex>
24 
25 #include "DispSync.h"
26 #include "EventThread.h"
27 
28 namespace android {
29 
DispSyncSource(DispSync * dispSync,nsecs_t phaseOffset,bool traceVsync,const char * name)30 DispSyncSource::DispSyncSource(DispSync* dispSync, nsecs_t phaseOffset, bool traceVsync,
31                                const char* name)
32       : mName(name),
33         mTraceVsync(traceVsync),
34         mVsyncOnLabel(base::StringPrintf("VsyncOn-%s", name)),
35         mVsyncEventLabel(base::StringPrintf("VSYNC-%s", name)),
36         mDispSync(dispSync),
37         mPhaseOffset(phaseOffset) {}
38 
setVSyncEnabled(bool enable)39 void DispSyncSource::setVSyncEnabled(bool enable) {
40     std::lock_guard lock(mVsyncMutex);
41     if (enable) {
42         status_t err = mDispSync->addEventListener(mName, mPhaseOffset,
43                                                    static_cast<DispSync::Callback*>(this),
44                                                    mLastCallbackTime);
45         if (err != NO_ERROR) {
46             ALOGE("error registering vsync callback: %s (%d)", strerror(-err), err);
47         }
48         // ATRACE_INT(mVsyncOnLabel.c_str(), 1);
49     } else {
50         status_t err = mDispSync->removeEventListener(static_cast<DispSync::Callback*>(this),
51                                                       &mLastCallbackTime);
52         if (err != NO_ERROR) {
53             ALOGE("error unregistering vsync callback: %s (%d)", strerror(-err), err);
54         }
55         // ATRACE_INT(mVsyncOnLabel.c_str(), 0);
56     }
57     mEnabled = enable;
58 }
59 
setCallback(VSyncSource::Callback * callback)60 void DispSyncSource::setCallback(VSyncSource::Callback* callback) {
61     std::lock_guard lock(mCallbackMutex);
62     mCallback = callback;
63 }
64 
setPhaseOffset(nsecs_t phaseOffset)65 void DispSyncSource::setPhaseOffset(nsecs_t phaseOffset) {
66     std::lock_guard lock(mVsyncMutex);
67 
68     // Normalize phaseOffset to [0, period)
69     auto period = mDispSync->getPeriod();
70     phaseOffset %= period;
71     if (phaseOffset < 0) {
72         // If we're here, then phaseOffset is in (-period, 0). After this
73         // operation, it will be in (0, period)
74         phaseOffset += period;
75     }
76     mPhaseOffset = phaseOffset;
77 
78     // If we're not enabled, we don't need to mess with the listeners
79     if (!mEnabled) {
80         return;
81     }
82 
83     status_t err =
84             mDispSync->changePhaseOffset(static_cast<DispSync::Callback*>(this), mPhaseOffset);
85     if (err != NO_ERROR) {
86         ALOGE("error changing vsync offset: %s (%d)", strerror(-err), err);
87     }
88 }
89 
onDispSyncEvent(nsecs_t when)90 void DispSyncSource::onDispSyncEvent(nsecs_t when) {
91     VSyncSource::Callback* callback;
92     {
93         std::lock_guard lock(mCallbackMutex);
94         callback = mCallback;
95 
96         if (mTraceVsync) {
97             mValue = (mValue + 1) % 2;
98             ATRACE_INT(mVsyncEventLabel.c_str(), mValue);
99         }
100     }
101 
102     if (callback != nullptr) {
103         callback->onVSyncEvent(when);
104     }
105 }
106 
107 } // namespace android