Install signal handlers which push the signal to the top process which will try to gracefully shut down each child process

src/ckpool.c

@@ -134,6 +134,15 @@ static void rm_namepid(proc_instance_t *pi)
 	unlink(s);
 }
 
+/* Disable signal handlers for child processes, but simply pass them onto the
+ * parent process to shut down cleanly. */
+static void childsighandler(int sig)
+{
+	pid_t ppid = getppid();
+
+	kill(ppid, sig);
+}
+
 static void launch_process(proc_instance_t *pi)
 {
 	pid_t pid;
@@ -142,8 +151,15 @@ static void launch_process(proc_instance_t *pi)
 	if (pid < 0)
 		quit(1, "Failed to fork %s in launch_process", pi->processname);
 	if (!pid) {
+		struct sigaction handler;
 		int ret;
 
+		handler.sa_handler = &childsighandler;
+		handler.sa_flags = 0;
+		sigemptyset(&handler.sa_mask);
+		sigaction(SIGTERM, &handler, NULL);
+		sigaction(SIGINT, &handler, NULL);
+
 		rename_proc(pi->processname);
 		write_namepid(pi);
 		ret = pi->process(pi);
@@ -160,23 +176,47 @@ static void clean_up(ckpool_t *ckp)
 	dealloc(ckp->socket_dir);
 }
 
-static void shutdown_children(ckpool_t *ckp, int sig)
+static void __shutdown_children(ckpool_t *ckp, int sig)
 {
 	pthread_cancel(ckp->pth_watchdog);
 	join_pthread(ckp->pth_watchdog);
+
+	if (!kill(ckp->generator.pid, 0))
 		kill(ckp->generator.pid, sig);
+	if (!kill(ckp->stratifier.pid, 0))
 		kill(ckp->stratifier.pid, sig);
+	if (!kill(ckp->connector.pid, 0))
 		kill(ckp->connector.pid, sig);
 }
 
+static void shutdown_children(ckpool_t *ckp, int sig)
+{
+	pthread_cancel(ckp->pth_watchdog);
+	join_pthread(ckp->pth_watchdog);
+
+	__shutdown_children(ckp, sig);
+}
+
 static void sighandler(int sig)
 {
+	pthread_cancel(global_ckp->pth_watchdog);
+	join_pthread(global_ckp->pth_watchdog);
+
+	/* First attempt, send a shutdown message */
+	send_proc(&global_ckp->generator, "shutdown");
+	send_proc(&global_ckp->stratifier, "shutdown");
+	send_proc(&global_ckp->connector, "shutdown");
+
 	if (sig != 9) {
-		shutdown_children(global_ckp, 15);
-		pthread_cancel(global_ckp->pth_listener);
+		/* Wait a second, then send SIGTERM */
+		sleep(1);
+		__shutdown_children(global_ckp, SIGTERM);
+		/* Wait another second, then send SIGKILL */
 		sleep(1);
+		__shutdown_children(global_ckp, SIGKILL);
+		pthread_cancel(global_ckp->pth_listener);
 	} else {
-		shutdown_children(global_ckp, 9);
+		__shutdown_children(global_ckp, SIGKILL);
 		exit(1);
 	}
 }
@@ -367,11 +407,6 @@ int main(int argc, char **argv)
 
 	/* Ignore sigpipe */
 	signal(SIGPIPE, SIG_IGN);
-	handler.sa_handler = &sighandler;
-	handler.sa_flags = 0;
-	sigemptyset(&handler.sa_mask);
-	sigaction(SIGTERM, &handler, NULL);
-	sigaction(SIGINT, &handler, NULL);
 
 	ret = mkdir(ckp.socket_dir, 0700);
 	if (ret && errno != EEXIST)
@@ -408,6 +443,12 @@ int main(int argc, char **argv)
 	launch_process(&ckp.stratifier);
 	launch_process(&ckp.connector);
 
+	handler.sa_handler = &sighandler;
+	handler.sa_flags = 0;
+	sigemptyset(&handler.sa_mask);
+	sigaction(SIGTERM, &handler, NULL);
+	sigaction(SIGINT, &handler, NULL);
+
 	test_functions(&ckp);
 
 	create_pthread(&ckp.pth_watchdog, watchdog, &ckp);

src/connector.c

@@ -512,5 +512,5 @@ out:
 		send_proc(&ckp->main, "shutdown");
 		sleep(1);
 	}
-	return ret;
+	exit(ret);
 }

src/generator.c

@@ -46,8 +46,10 @@ retry:
 		goto retry;
 	}
 	LOGDEBUG("Generator received request: %s", buf);
-	if (!strncasecmp(buf, "shutdown", 8))
+	if (!strncasecmp(buf, "shutdown", 8)) {
+		ret = 0;
 		goto out;
+	}
 	if (!strncasecmp(buf, "getbase", 7)) {
 		if (!gen_gbtbase(cs, &gbt)) {
 			LOGWARNING("Failed to get block template from %s:%s",
@@ -154,5 +156,5 @@ out:
 		send_proc(&ckp->main, "shutdown");
 		sleep(1);
 	}
-	return ret;
+	exit(ret);
 }

src/libckpool.c

@@ -56,10 +56,7 @@ void create_pthread(pthread_t *thread, void *(*start_routine)(void *), void *arg
 
 void join_pthread(pthread_t thread)
 {
-	int ret = pthread_join(thread, NULL);
-
-	if (unlikely(ret))
-		quit(1, "Failed to pthread_join");
+	pthread_join(thread, NULL);
 }
 
 

src/stratifier.c

@@ -582,7 +582,7 @@ static void drop_client(int id)
 	ck_uilock(&instance_lock);
 }
 
-static int strat_loop(ckpool_t *ckp, proc_instance_t *pi)
+static int stratum_loop(ckpool_t *ckp, proc_instance_t *pi)
 {
 	int sockd, ret = 0, selret;
 	unixsock_t *us = &pi->us;
@@ -626,9 +626,10 @@ retry:
 		goto retry;
 	}
 	LOGDEBUG("Stratifier received request: %s", buf);
-	if (!strncasecmp(buf, "shutdown", 8))
+	if (!strncasecmp(buf, "shutdown", 8)) {
+		ret = 0;
 		goto out;
-	else if (!strncasecmp(buf, "update", 6)) {
+	} else if (!strncasecmp(buf, "update", 6)) {
 		update_base(ckp);
 		goto reset;
 	} else if (!strncasecmp(buf, "dropclient", 10)) {
@@ -1422,7 +1423,7 @@ int stratifier(proc_instance_t *pi)
 	pthread_t pth_blockupdate, pth_stratum_receiver, pth_stratum_sender;
 	pthread_t pth_statsupdate;
 	ckpool_t *ckp = pi->ckp;
-	int ret = 0;
+	int ret;
 
 	/* Store this for use elsewhere */
 	hex2bin(scriptsig_header_bin, scriptsig_header, 41);
@@ -1450,7 +1451,12 @@ int stratifier(proc_instance_t *pi)
 
 	cklock_init(&share_lock);
 
-	strat_loop(ckp, pi);
+	ret = stratum_loop(ckp, pi);
+	LOGINFO("%s stratifier exiting with return code %d", ckp->name, ret);
+	if (ret) {
+		send_proc(&ckp->main, "shutdown");
+		sleep(1);
+	}
 
-	return ret;
+	exit(ret);
 }