Function StartUnixWorker

lib/cli/daemoncommand.cpp:464–603

* Starts seamless worker process doing the actual work (config loading, ...) * * @param configs Files to read config from * @param closeConsoleLog Whether to close the console log after config loading * @param stderrFile Where to log errors * * @return The worker's PID on success, -1 on fork(2) failure, -2 if the worker couldn't load its config */

 * @return The worker's PID on success, -1 on fork(2) failure, -2 if the worker couldn't load its config
 */
static pid_t StartUnixWorker(const std::vector<std::string>& configs, bool closeConsoleLog = false, const String& stderrFile = String())
{
	Log(LogNotice, "cli")
		<< "Spawning seamless worker process doing the actual work";

	try {
		Application::UninitializeBase();
	} catch (const std::exception& ex) {
		Log(LogCritical, "cli")
			<< "Failed to stop thread pool before forking, unexpected error: " << DiagnosticInformation(ex);
		exit(EXIT_FAILURE);
	}

	/* Block the signal handlers we'd like to change in the child process until we changed them.
	 * Block SIGUSR2 handler until we've set l_CurrentlyStartingUnixWorkerPid.
	 */
	(void)sigprocmask(SIG_BLOCK, &l_UnixWorkerSignals, nullptr);

	pid_t pid = fork();

	switch (pid) {
		case -1:
			Log(LogCritical, "cli")
				<< "fork() failed with error code " << errno << ", \"" << Utility::FormatErrorNumber(errno) << "\"";

			try {
				Application::InitializeBase();
			} catch (const std::exception& ex) {
				Log(LogCritical, "cli")
					<< "Failed to re-initialize thread pool after forking (parent): " << DiagnosticInformation(ex);
				exit(EXIT_FAILURE);
			}

			(void)sigprocmask(SIG_UNBLOCK, &l_UnixWorkerSignals, nullptr);
			return -1;

		case 0:
			try {
				{
					struct sigaction sa;
					memset(&sa, 0, sizeof(sa));

					sa.sa_handler = SIG_DFL;

					(void)sigaction(SIGUSR1, &sa, nullptr);
				}

				{
					struct sigaction sa;
					memset(&sa, 0, sizeof(sa));

					sa.sa_handler = SIG_IGN;

					(void)sigaction(SIGHUP, &sa, nullptr);
				}

				{
					struct sigaction sa;