Fix #28 add a watchdog for the stats server

include/monitor.h

@@ -114,5 +114,6 @@ int pyfcgi_monitor_parse_inet_addr(const char*, int, pyfcgi_monitor_addr_t*,
 	int*);
 
 void pyfcgi_monitor_sighandler(int signum);
+void pyfcgi_monitor_timeout(int signum);
 
 #endif

src/monitor.c

@@ -4,6 +4,7 @@ static pyfcgi_monitor_t pyfcgi_mon;
 
 static void clean_exit(int status)
 {
+	pyfcgi_wd_stop();
 	if(pyfcgi_mon.sockserv)
 	{
 		if(pyfcgi_mon.sockcli)
@@ -38,8 +39,12 @@ pid_t pyfcgi_spawn_monitor()
 {
 	pid_t res;
 	struct sigaction act, actdrop;
+	struct timespec wd_delay;
 	int err;
 
+	wd_delay.tv_sec = 0;
+	wd_delay.tv_nsec = 250000000; //0.25s
+
 	act.sa_handler = pyfcgi_monitor_sighandler;
 	sigemptyset(&act.sa_mask);
 	act.sa_flags = 0;
@@ -85,6 +90,15 @@ pid_t pyfcgi_spawn_monitor()
 			pyfcgi_log(LOG_WARNING, "Unable to restore ALARM sigaction : %s",
 				strerror(errno));
 		}
+
+		if(pyfcgi_wd_init(pyfcgi_monitor_timeout, &wd_delay) < 0)
+		{
+			pyfcgi_log(LOG_ALERT,
+				"Unable to start watchdog, sleep 1s then exiting...");
+			sleep(1);
+			exit(PYFCGI_FATAL);
+		}
+
 		pyfcgi_monitor_loop();
 		pyfcgi_log(LOG_ALERT, "Monitor loop should never return but just did it...");
 		clean_exit(PYFCGI_FATAL);
@@ -208,6 +222,7 @@ void pyfcgi_monitor_stream_loop(pyfcgi_monitor_addr_t addr_serv)
 	{
 		sockcli = pyfcgi_mon.sockcli = accept(pyfcgi_mon.sockserv,
 			(struct sockaddr*)&cliaddr, &addrlen);
+		pyfcgi_wd_arm(); //watchdog
 		if(sockcli < 0)
 		{
 			err = errno;
@@ -243,6 +258,7 @@ void pyfcgi_monitor_stream_loop(pyfcgi_monitor_addr_t addr_serv)
 		}
 		shutdown(sockcli, SHUT_RDWR);
 		close(sockcli);
+		pyfcgi_wd_pause(); //watchdog
 		pyfcgi_mon.sockcli = 0;
 		
 		addrlen = sizeof(cliaddr);
@@ -451,3 +467,9 @@ void pyfcgi_monitor_sighandler(int signum)
 	clean_exit(0);
 }
 
+void pyfcgi_monitor_timeout(int signum)
+{
+	pyfcgi_log(LOG_ALERT, "Monitor server timeout, killed by watchdog");
+	clean_exit(PYFCGI_TIMEOUT);
+}
+