1 /*
2  * Copyright (C) 2020 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 "Watchdog"
18 
19 #include <watchdog/Watchdog.h>
20 
21 #include <android-base/logging.h>
22 #include <android-base/threads.h>
23 #include <signal.h>
24 #include <time.h>
25 #include <cstring>
26 #include <utils/Log.h>
27 
28 namespace android {
29 
Watchdog(::std::chrono::steady_clock::duration timeout)30 Watchdog::Watchdog(::std::chrono::steady_clock::duration timeout) {
31     // Create the timer.
32     struct sigevent sev;
33     sev.sigev_notify = SIGEV_THREAD_ID;
34     sev.sigev_notify_thread_id = base::GetThreadId();
35     sev.sigev_signo = SIGABRT;
36     sev.sigev_value.sival_ptr = &mTimerId;
37     int err = timer_create(CLOCK_MONOTONIC, &sev, &mTimerId);
38     if (err != 0) {
39         PLOG(FATAL) << "Failed to create timer";
40     }
41 
42     // Start the timer.
43     struct itimerspec spec;
44     memset(&spec, 0, sizeof(spec));
45     auto ns = std::chrono::duration_cast<std::chrono::nanoseconds>(timeout);
46     LOG_ALWAYS_FATAL_IF(timeout.count() <= 0, "Duration must be positive");
47     spec.it_value.tv_sec = ns.count() / 1000000000;
48     spec.it_value.tv_nsec = ns.count() % 1000000000;
49     err = timer_settime(mTimerId, 0, &spec, nullptr);
50     if (err != 0) {
51         PLOG(FATAL) << "Failed to start timer";
52     }
53 }
54 
~Watchdog()55 Watchdog::~Watchdog() {
56     // Delete the timer.
57     int err = timer_delete(mTimerId);
58     if (err != 0) {
59         PLOG(FATAL) << "Failed to delete timer";
60     }
61 }
62 
63 }  // namespace android
64