1 /*
2 * Copyright (C) 2012 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 LOG_TAG "AudioWatchdog"
18 //#define LOG_NDEBUG 0
19
20 #include "Configuration.h"
21 #include <utils/Log.h>
22 #include "AudioWatchdog.h"
23
24 #ifdef AUDIO_WATCHDOG
25
26 namespace android {
27
dump(int fd)28 void AudioWatchdogDump::dump(int fd)
29 {
30 char buf[32];
31 if (mMostRecent != 0) {
32 // includes NUL terminator
33 ctime_r(&mMostRecent, buf);
34 } else {
35 strcpy(buf, "N/A\n");
36 }
37 dprintf(fd, "Watchdog: underruns=%u, logs=%u, most recent underrun log at %s",
38 mUnderruns, mLogs, buf);
39 }
40
threadLoop()41 bool AudioWatchdog::threadLoop()
42 {
43 {
44 AutoMutex _l(mMyLock);
45 if (mPaused) {
46 mMyCond.wait(mMyLock);
47 // ignore previous timestamp after resume()
48 mOldTsValid = false;
49 // force an immediate log on first underrun after resume()
50 mLogTs.tv_sec = MIN_TIME_BETWEEN_LOGS_SEC;
51 mLogTs.tv_nsec = 0;
52 // caller will check for exitPending()
53 return true;
54 }
55 }
56 struct timespec newTs;
57 int rc = clock_gettime(CLOCK_MONOTONIC, &newTs);
58 if (rc != 0) {
59 pause();
60 return false;
61 }
62 if (!mOldTsValid) {
63 mOldTs = newTs;
64 mOldTsValid = true;
65 return true;
66 }
67 time_t sec = newTs.tv_sec - mOldTs.tv_sec;
68 long nsec = newTs.tv_nsec - mOldTs.tv_nsec;
69 if (nsec < 0) {
70 --sec;
71 nsec += 1000000000;
72 }
73 mOldTs = newTs;
74 // cycleNs is same as sec*1e9 + nsec, but limited to about 4 seconds
75 uint32_t cycleNs = nsec;
76 if (sec > 0) {
77 if (sec < 4) {
78 cycleNs += sec * 1000000000;
79 } else {
80 cycleNs = 4000000000u;
81 }
82 }
83 mLogTs.tv_sec += sec;
84 if ((mLogTs.tv_nsec += nsec) >= 1000000000) {
85 mLogTs.tv_sec++;
86 mLogTs.tv_nsec -= 1000000000;
87 }
88 if (cycleNs > mMaxCycleNs) {
89 mDump->mUnderruns = ++mUnderruns;
90 if (mLogTs.tv_sec >= MIN_TIME_BETWEEN_LOGS_SEC) {
91 mDump->mLogs = ++mLogs;
92 mDump->mMostRecent = time(NULL);
93 ALOGW("Insufficient CPU for load: expected=%.1f actual=%.1f ms; underruns=%u logs=%u",
94 mPeriodNs * 1e-6, cycleNs * 1e-6, mUnderruns, mLogs);
95 mLogTs.tv_sec = 0;
96 mLogTs.tv_nsec = 0;
97 }
98 }
99 struct timespec req;
100 req.tv_sec = 0;
101 req.tv_nsec = mPeriodNs;
102 rc = nanosleep(&req, NULL);
103 if (!((rc == 0) || (rc == -1 && errno == EINTR))) {
104 pause();
105 return false;
106 }
107 return true;
108 }
109
requestExit()110 void AudioWatchdog::requestExit()
111 {
112 // must be in this order to avoid a race condition
113 Thread::requestExit();
114 resume();
115 }
116
pause()117 void AudioWatchdog::pause()
118 {
119 AutoMutex _l(mMyLock);
120 mPaused = true;
121 }
122
resume()123 void AudioWatchdog::resume()
124 {
125 AutoMutex _l(mMyLock);
126 if (mPaused) {
127 mPaused = false;
128 mMyCond.signal();
129 }
130 }
131
setDump(AudioWatchdogDump * dump)132 void AudioWatchdog::setDump(AudioWatchdogDump *dump)
133 {
134 mDump = dump != NULL ? dump : &mDummyDump;
135 }
136
137 } // namespace android
138
139 #endif // AUDIO_WATCHDOG
140