int ServerApplication::init(int argc, char *argv[]) {
// Hide child's output
if (hasFeature(FEATURE_SERVER) && options["child"].toBoolean())
options["log-to-screen"].setDefault(false);
int ret = Application::init(argc, argv);
if (ret == -1) return -1;
if (!hasFeature(FEATURE_SERVER)) return ret;
if (!options["child"].toBoolean()) {
#ifndef _WIN32
if (options["fork"].toBoolean()) {
// Note, all threads must be stopped before daemonize() forks and
// SignalManager runs in a thread.
SignalManager::instance().setEnabled(false);
SystemUtilities::daemonize();
SignalManager::instance().setEnabled(true);
}
#endif
if (options["pid"].toBoolean()) {
// Try to acquire an exclusive lock
new ProcessLock(options["pid-file"], 10); // OK to leak
LOG_INFO(1, "Acquired exclusive lock on " << options["pid-file"]);
}
}
#ifndef _WIN32
try {
if (options["run-as"].hasValue()) {
LOG_INFO(1, "Switching to user " << options["run-as"]);
SystemUtilities::setUser(options["run-as"]);
}
} CBANG_CATCH_ERROR;
#endif
if (!options["child"].toBoolean() && options["respawn"].toBoolean()) {
#ifndef _WIN32
// Child restart handler
SignalManager::instance().addHandler(SIGUSR1, this);
#endif
// Setup child arguments
vector<string> args;
args.push_back(argv[0]);
args.push_back((char *)"--child");
args.push_back((char *)"--lifeline");
args.push_back(String(SystemUtilities::getPID()));
args.insert(args.end(), argv + 1, argv + argc);
unsigned lastRespawn = 0;
unsigned respawnCount = 0;
while (!shouldQuit()) {
// Check respawn rate
unsigned now = Time::now();
if (now - lastRespawn < 60) {
if (++respawnCount == 5) {
LOG_ERROR("Respawning too fast. Exiting.");
break;
}
} else respawnCount = 0;
lastRespawn = now;
// Spawn child
Subprocess child;
child.exec(args, Subprocess::NULL_STDOUT | Subprocess::NULL_STDERR);
uint64_t killTime = 0;
while (child.isRunning()) {
if (!killTime && (restartChild || shouldQuit())) {
LOG_INFO(1, "Shutting down child at PID=" << child.getPID());
child.interrupt();
restartChild = false;
killTime = Time::now() + 300; // Give it 5 mins to shutdown
}
if (killTime && killTime < Time::now()) {
LOG_INFO(1, "Child failed to shutdown cleanly, killing");
killTime = 0;
child.kill();
}
Timer::sleep(0.1);
}
LOG_INFO(1, "Child exited with return code " << child.getReturnCode());
}
exit(0);
}
return ret;
}
