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 } else {
44 *pids = audioHalPids[curAudioHalPids % kNumAudioHalPidsVectors];
45 }
46 }
47
48 /* static */
setAudioHalPids(const std::vector<pid_t> & pids)49 void TimeCheck::setAudioHalPids(const std::vector<pid_t>& pids) {
50 accessAudioHalPids(&(const_cast<std::vector<pid_t>&>(pids)), true);
51 }
52
53 /* static */
getAudioHalPids()54 std::vector<pid_t> TimeCheck::getAudioHalPids() {
55 std::vector<pid_t> pids;
56 accessAudioHalPids(&pids, false);
57 return pids;
58 }
59
60 /* static */
getTimeCheckThread()61 sp<TimeCheck::TimeCheckThread> TimeCheck::getTimeCheckThread()
62 {
63 static sp<TimeCheck::TimeCheckThread> sTimeCheckThread = new TimeCheck::TimeCheckThread();
64 return sTimeCheckThread;
65 }
66
TimeCheck(const char * tag,uint32_t timeoutMs)67 TimeCheck::TimeCheck(const char *tag, uint32_t timeoutMs)
68 : mEndTimeNs(getTimeCheckThread()->startMonitoring(tag, timeoutMs))
69 {
70 }
71
~TimeCheck()72 TimeCheck::~TimeCheck() {
73 getTimeCheckThread()->stopMonitoring(mEndTimeNs);
74 }
75
~TimeCheckThread()76 TimeCheck::TimeCheckThread::~TimeCheckThread()
77 {
78 AutoMutex _l(mMutex);
79 requestExit();
80 mMonitorRequests.clear();
81 mCond.signal();
82 }
83
startMonitoring(const char * tag,uint32_t timeoutMs)84 nsecs_t TimeCheck::TimeCheckThread::startMonitoring(const char *tag, uint32_t timeoutMs) {
85 Mutex::Autolock _l(mMutex);
86 nsecs_t endTimeNs = systemTime() + milliseconds(timeoutMs);
87 for (; mMonitorRequests.indexOfKey(endTimeNs) >= 0; ++endTimeNs);
88 mMonitorRequests.add(endTimeNs, tag);
89 mCond.signal();
90 return endTimeNs;
91 }
92
stopMonitoring(nsecs_t endTimeNs)93 void TimeCheck::TimeCheckThread::stopMonitoring(nsecs_t endTimeNs) {
94 Mutex::Autolock _l(mMutex);
95 mMonitorRequests.removeItem(endTimeNs);
96 mCond.signal();
97 }
98
threadLoop()99 bool TimeCheck::TimeCheckThread::threadLoop()
100 {
101 status_t status = TIMED_OUT;
102 {
103 AutoMutex _l(mMutex);
104
105 if (exitPending()) {
106 return false;
107 }
108
109 nsecs_t endTimeNs = INT64_MAX;
110 const char *tag = "<unspecified>";
111 // KeyedVector mMonitorRequests is ordered so take first entry as next timeout
112 if (mMonitorRequests.size() != 0) {
113 endTimeNs = mMonitorRequests.keyAt(0);
114 tag = mMonitorRequests.valueAt(0);
115 }
116
117 const nsecs_t waitTimeNs = endTimeNs - systemTime();
118 if (waitTimeNs > 0) {
119 status = mCond.waitRelative(mMutex, waitTimeNs);
120 }
121 if (status != NO_ERROR) {
122 // Generate audio HAL processes tombstones and allow time to complete
123 // before forcing restart
124 std::vector<pid_t> pids = getAudioHalPids();
125 if (pids.size() != 0) {
126 for (const auto& pid : pids) {
127 ALOGI("requesting tombstone for pid: %d", pid);
128 sigqueue(pid, DEBUGGER_SIGNAL, {.sival_int = 0});
129 }
130 sleep(1);
131 } else {
132 ALOGI("No HAL process pid available, skipping tombstones");
133 }
134 LOG_EVENT_STRING(LOGTAG_AUDIO_BINDER_TIMEOUT, tag);
135 LOG_ALWAYS_FATAL("TimeCheck timeout for %s", tag);
136 }
137 }
138 return true;
139 }
140
141 }; // namespace android
142