1 /*
2 * Copyright (C) 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 LOG_TAG "TimeCheck"
18
19 #include <utils/Log.h>
20 #include <mediautils/TimeCheck.h>
21 #include <mediautils/EventLog.h>
22 #include "debuggerd/handler.h"
23
24 namespace android {
25
26 // Audio HAL server pids vector used to generate audio HAL processes tombstone
27 // when audioserver watchdog triggers.
28 // We use a lockless storage to avoid potential deadlocks in the context of watchdog
29 // trigger.
30 // Protection again simultaneous writes is not needed given one update takes place
31 // during AudioFlinger construction and other comes necessarily later once the IAudioFlinger
32 // interface is available.
33 // The use of an atomic index just guaranties that current vector is fully initialized
34 // when read.
35 /* static */
accessAudioHalPids(std::vector<pid_t> * pids,bool update)36 void TimeCheck::accessAudioHalPids(std::vector<pid_t>* pids, bool update) {
37 static constexpr int kNumAudioHalPidsVectors = 3;
38 static std::vector<pid_t> audioHalPids[kNumAudioHalPidsVectors];
39 static std::atomic<int> curAudioHalPids = 0;
40
41 if (update) {
42 audioHalPids[(curAudioHalPids + 1) % kNumAudioHalPidsVectors] = *pids;
43 curAudioHalPids++;
44 } else {
45 *pids = audioHalPids[curAudioHalPids];
46 }
47 }
48
49 /* static */
setAudioHalPids(const std::vector<pid_t> & pids)50 void TimeCheck::setAudioHalPids(const std::vector<pid_t>& pids) {
51 accessAudioHalPids(&(const_cast<std::vector<pid_t>&>(pids)), true);
52 }
53
54 /* static */
getAudioHalPids()55 std::vector<pid_t> TimeCheck::getAudioHalPids() {
56 std::vector<pid_t> pids;
57 accessAudioHalPids(&pids, false);
58 return pids;
59 }
60
61 /* static */
getTimeCheckThread()62 sp<TimeCheck::TimeCheckThread> TimeCheck::getTimeCheckThread()
63 {
64 static sp<TimeCheck::TimeCheckThread> sTimeCheckThread = new TimeCheck::TimeCheckThread();
65 return sTimeCheckThread;
66 }
67
TimeCheck(const char * tag,uint32_t timeoutMs)68 TimeCheck::TimeCheck(const char *tag, uint32_t timeoutMs)
69 : mEndTimeNs(getTimeCheckThread()->startMonitoring(tag, timeoutMs))
70 {
71 }
72
~TimeCheck()73 TimeCheck::~TimeCheck() {
74 getTimeCheckThread()->stopMonitoring(mEndTimeNs);
75 }
76
~TimeCheckThread()77 TimeCheck::TimeCheckThread::~TimeCheckThread()
78 {
79 AutoMutex _l(mMutex);
80 requestExit();
81 mMonitorRequests.clear();
82 mCond.signal();
83 }
84
startMonitoring(const char * tag,uint32_t timeoutMs)85 nsecs_t TimeCheck::TimeCheckThread::startMonitoring(const char *tag, uint32_t timeoutMs) {
86 Mutex::Autolock _l(mMutex);
87 nsecs_t endTimeNs = systemTime() + milliseconds(timeoutMs);
88 for (; mMonitorRequests.indexOfKey(endTimeNs) >= 0; ++endTimeNs);
89 mMonitorRequests.add(endTimeNs, tag);
90 mCond.signal();
91 return endTimeNs;
92 }
93
stopMonitoring(nsecs_t endTimeNs)94 void TimeCheck::TimeCheckThread::stopMonitoring(nsecs_t endTimeNs) {
95 Mutex::Autolock _l(mMutex);
96 mMonitorRequests.removeItem(endTimeNs);
97 mCond.signal();
98 }
99
threadLoop()100 bool TimeCheck::TimeCheckThread::threadLoop()
101 {
102 status_t status = TIMED_OUT;
103 {
104 AutoMutex _l(mMutex);
105
106 if (exitPending()) {
107 return false;
108 }
109
110 nsecs_t endTimeNs = INT64_MAX;
111 const char *tag = "<unspecified>";
112 // KeyedVector mMonitorRequests is ordered so take first entry as next timeout
113 if (mMonitorRequests.size() != 0) {
114 endTimeNs = mMonitorRequests.keyAt(0);
115 tag = mMonitorRequests.valueAt(0);
116 }
117
118 const nsecs_t waitTimeNs = endTimeNs - systemTime();
119 if (waitTimeNs > 0) {
120 status = mCond.waitRelative(mMutex, waitTimeNs);
121 }
122 if (status != NO_ERROR) {
123 // Generate audio HAL processes tombstones and allow time to complete
124 // before forcing restart
125 std::vector<pid_t> pids = getAudioHalPids();
126 if (pids.size() != 0) {
127 for (const auto& pid : pids) {
128 ALOGI("requesting tombstone for pid: %d", pid);
129 sigqueue(pid, DEBUGGER_SIGNAL, {.sival_int = 0});
130 }
131 sleep(1);
132 } else {
133 ALOGI("No HAL process pid available, skipping tombstones");
134 }
135 LOG_EVENT_STRING(LOGTAG_AUDIO_BINDER_TIMEOUT, tag);
136 LOG_ALWAYS_FATAL("TimeCheck timeout for %s", tag);
137 }
138 }
139 return true;
140 }
141
142 }; // namespace android
143