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 "carwatchdogd"
18 
19 #include "ServiceManager.h"
20 
21 #include <android-base/chrono_utils.h>
22 #include <android-base/properties.h>
23 #include <android-base/result.h>
24 #include <binder/IPCThreadState.h>
25 #include <binder/IServiceManager.h>
26 #include <binder/ProcessState.h>
27 #include <log/log.h>
28 #include <utils/Looper.h>
29 
30 #include <signal.h>
31 
32 #include <thread>  // NOLINT(build/c++11)
33 
34 using ::android::IPCThreadState;
35 using ::android::Looper;
36 using ::android::ProcessState;
37 using ::android::sp;
38 using ::android::automotive::watchdog::ServiceManager;
39 using ::android::base::Result;
40 
41 namespace {
42 
43 const size_t kMaxBinderThreadCount = 16;
44 
sigHandler(int sig)45 void sigHandler(int sig) {
46     IPCThreadState::self()->stopProcess();
47     ServiceManager::terminateServices();
48     ALOGW("car watchdog server terminated on receiving signal %d.", sig);
49     exit(1);
50 }
51 
registerSigHandler()52 void registerSigHandler() {
53     struct sigaction sa;
54     sigemptyset(&sa.sa_mask);
55     sa.sa_flags = 0;
56     sa.sa_handler = sigHandler;
57     sigaction(SIGQUIT, &sa, nullptr);
58     sigaction(SIGTERM, &sa, nullptr);
59 }
60 
61 }  // namespace
62 
main(int,char **)63 int main(int /*argc*/, char** /*argv*/) {
64     // Set up the looper
65     sp<Looper> looper(Looper::prepare(/*opts=*/0));
66 
67     // Start the services
68     auto result = ServiceManager::startServices(looper);
69     if (!result.ok()) {
70         ALOGE("Failed to start services: %s", result.error().message().c_str());
71         ServiceManager::terminateServices();
72         exit(result.error().code());
73     }
74 
75     registerSigHandler();
76 
77     // Wait for the service manager before starting binder mediator.
78     while (android::base::GetProperty("init.svc.servicemanager", "") != "running") {
79         // Poll frequent enough so the CarWatchdogDaemonHelper can connect to the daemon during
80         // system boot up.
81         std::this_thread::sleep_for(250ms);
82     }
83 
84     // Set up the binder
85     sp<ProcessState> ps(ProcessState::self());
86     ps->setThreadPoolMaxThreadCount(kMaxBinderThreadCount);
87     ps->startThreadPool();
88     ps->giveThreadPoolName();
89     IPCThreadState::self()->disableBackgroundScheduling(true);
90 
91     result = ServiceManager::startBinderMediator();
92     if (!result.ok()) {
93         ALOGE("Failed to start binder mediator: %s", result.error().message().c_str());
94         ServiceManager::terminateServices();
95         exit(result.error().code());
96     }
97 
98     // Loop forever -- the health check runs on this thread in a handler, and the binder calls
99     // remain responsive in their pool of threads.
100     while (true) {
101         looper->pollAll(/*timeoutMillis=*/-1);
102     }
103     ALOGW("Car watchdog server escaped from its loop.");
104 
105     return 0;
106 }
107