Make all child processes ping the parent process at regular intervals and then die if it has disappeared. Do not attempt to send unix messages to dead processes and abort instantly on socket EINTR

src/ckpool.c

@@ -71,6 +71,17 @@ out:
 	return NULL;
 }
 
+bool ping_main(ckpool_t *ckp)
+{
+	char *buf;
+
+	buf = send_recv_proc(&ckp->main, "ping");
+	if (!buf)
+		return false;
+	free(buf);
+	return true;
+}
+
 /* Open the file in path, check if there is a pid in there that still exists
  * and if not, write the pid into that file. */
 static bool write_pid(ckpool_t *ckp, const char *path, pid_t pid)

src/ckpool.h

@@ -108,6 +108,7 @@ struct ckpool_instance {
 
 ckpool_t *global_ckp;
 
+bool ping_main(ckpool_t *ckp);
 int process_exit(ckpool_t *ckp, proc_instance_t *pi, int ret);
 
 #define ASPRINTF(strp, fmt, ...) do { \

src/connector.c

@@ -431,11 +431,20 @@ static client_instance_t *client_by_id(conn_instance_t *ci, int id)
 
 static int connector_loop(proc_instance_t *pi, conn_instance_t *ci)
 {
-	int sockd, client_id, ret = 0;
+	int sockd, client_id, ret = 0, selret;
 	unixsock_t *us = &pi->us;
+	ckpool_t *ckp = pi->ckp;
 	char *buf = NULL;
 	json_t *json_msg;
 
+	do {
+		selret = wait_read_select(us->sockd, 5);
+		if (!selret && !ping_main(ckp)) {
+			LOGEMERG("Connector failed to ping main process, exiting");
+			ret = 1;
+			goto out;
+		}
+	} while (selret < 1);
 retry:
 	sockd = accept(us->sockd, NULL, NULL);
 	if (sockd < 0) {

src/generator.c

@@ -173,10 +173,10 @@ static void kill_server(server_instance_t *si)
 
 static int gen_loop(proc_instance_t *pi)
 {
+	int sockd = -1, ret = 0, selret;
 	server_instance_t *si = NULL;
 	unixsock_t *us = &pi->us;
 	ckpool_t *ckp = pi->ckp;
-	int sockd, ret = 0;
 	char *buf = NULL;
 	connsock_t *cs;
 	gbtbase_t *gbt;
@@ -188,7 +188,17 @@ reconnect:
 	si = live_server(ckp);
 	gbt = si->data;
 	cs = &si->cs;
+
 retry:
+	do {
+		selret = wait_read_select(us->sockd, 5);
+		if (!selret && !ping_main(ckp)) {
+			LOGEMERG("Generator failed to ping main process, exiting");
+			ret = 1;
+			goto out;
+		}
+	} while (selret < 1);
+
 	sockd = accept(us->sockd, NULL, NULL);
 	if (sockd < 0) {
 		if (interrupted())
@@ -1163,10 +1173,10 @@ static void kill_proxy(proxy_instance_t *proxi)
 
 static int proxy_loop(proc_instance_t *pi)
 {
+	int sockd = -1, ret = 0, selret;
 	unixsock_t *us = &pi->us;
 	ckpool_t *ckp = pi->ckp;
 	proxy_instance_t *proxi;
-	int sockd, ret = 0;
 	char *buf = NULL;
 
 reconnect:
@@ -1177,6 +1187,14 @@ reconnect:
 	send_proc(ckp->stratifier, "notify");
 	proxi->notified = false;
 
+	do {
+		selret = wait_read_select(us->sockd, 5);
+		if (!selret && !ping_main(ckp)) {
+			LOGEMERG("Generator failed to ping main process, exiting");
+			ret = 1;
+			goto out;
+		}
+	} while (selret < 1);
 retry:
 	sockd = accept(us->sockd, NULL, NULL);
 	if (sockd < 0) {

src/libckpool.c

@@ -671,12 +671,9 @@ int wait_read_select(int sockd, int timeout)
 	tv_timeout.tv_sec = timeout;
 	tv_timeout.tv_usec = 0;
 
-retry:
 	FD_ZERO(&readfs);
 	FD_SET(sockd, &readfs);
 	ret = select(sockd + 1, &readfs, NULL, NULL, &tv_timeout);
-	if (unlikely(ret < 1 &&interrupted()))
-		goto retry;
 	return ret;
 }
 
@@ -750,12 +747,9 @@ int wait_write_select(int sockd, int timeout)
 	tv_timeout.tv_sec = timeout;
 	tv_timeout.tv_usec = 0;
 
-retry:
 	FD_ZERO(&writefds);
 	FD_SET(sockd, &writefds);
 	ret = select(sockd + 1, NULL, &writefds, NULL, &tv_timeout);
-	if (unlikely(ret < 1 &&interrupted()))
-		goto retry;
 	return ret;
 }
 
@@ -793,7 +787,7 @@ bool _send_unix_msg(int sockd, const char *buf, const char *file, const char *fu
 		goto out;
 	}
 	msglen = htole32(len);
-	ret = wait_write_select(sockd, 60);
+	ret = wait_write_select(sockd, 5);
 	if (unlikely(ret < 1)) {
 		LOGERR("Select1 failed in send_unix_msg");
 		goto out;
@@ -803,7 +797,7 @@ bool _send_unix_msg(int sockd, const char *buf, const char *file, const char *fu
 		LOGERR("Failed to write 4 byte length in send_unix_msg");
 		goto out;
 	}
-	ret = wait_write_select(sockd, 60);
+	ret = wait_write_select(sockd, 5);
 	if (unlikely(ret < 1)) {
 		LOGERR("Select2 failed in send_unix_msg");
 		goto out;
@@ -836,6 +830,10 @@ bool _send_proc(proc_instance_t *pi, const char *msg, const char *file, const ch
 		LOGERR("Attempted to send null message to socket %s in send_proc", path);
 		goto out;
 	}
+	if (unlikely(kill(pi->pid, 0))) {
+		LOGALERT("Attempting to send message %s to dead process %s", msg, pi->processname);
+		goto out;
+	}
 	sockd = open_unix_client(path);
 	if (unlikely(sockd < 0)) {
 		LOGWARNING("Failed to open socket %s", path);
@@ -867,6 +865,10 @@ char *_send_recv_proc(proc_instance_t *pi, const char *msg, const char *file, co
 		LOGERR("Attempted to send null message to socket %s in send_proc", path);
 		goto out;
 	}
+	if (unlikely(kill(pi->pid, 0))) {
+		LOGALERT("Attempting to send message %s to dead process %s", msg, pi->processname);
+		goto out;
+	}
 	sockd = open_unix_client(path);
 	if (unlikely(sockd < 0)) {
 		LOGWARNING("Failed to open socket %s", path);

src/stratifier.c

@@ -875,36 +875,36 @@ static void block_solve(ckpool_t *ckp)
 
 static int stratum_loop(ckpool_t *ckp, proc_instance_t *pi)
 {
-	int sockd, ret = 0, selret;
+	int sockd, ret = 0, selret = 0;
 	unixsock_t *us = &pi->us;
-	tv_t timeout, *to;
 	char *buf = NULL;
-	fd_set readfds;
+	tv_t start_tv;
 
-	if (ckp->proxy)
-		to = NULL;
-	else
-		to = &timeout;
-reset:
-	timeout.tv_sec = ckp->update_interval;
-	timeout.tv_usec = 0;
+	tv_time(&start_tv);
 retry:
-	FD_ZERO(&readfds);
-	FD_SET(us->sockd, &readfds);
-	selret = select(us->sockd + 1, &readfds, NULL, NULL, to);
-	if (selret < 0) {
-		if (interrupted())
-			goto retry;
-		LOGERR("Select failed in strat_loop, killing stratifier!");
-		sleep(5);
+	do {
+		if (!ckp->proxy) {
+			double tdiff;
+			tv_t end_tv;
+
+			tv_time(&end_tv);
+			tdiff = tvdiff(&end_tv, &start_tv);
+			if (tdiff > ckp->update_interval) {
+				copy_tv(&start_tv, &end_tv);
+				LOGDEBUG("%ds elapsed in strat_loop, updating gbt base",
+					 ckp->update_interval);
+				update_base(ckp);
+				continue;
+			}
+		}
+		selret = wait_read_select(us->sockd, 5);
+		if (!selret && !ping_main(ckp)) {
+			LOGEMERG("Generator failed to ping main process, exiting");
 			ret = 1;
 			goto out;
 		}
-	if (!selret) {
-		LOGDEBUG("%ds elapsed in strat_loop, updating gbt base", ckp->update_interval);
-		update_base(ckp);
-		goto reset;
-	}
+	} while (selret < 1);
+
 	sockd = accept(us->sockd, NULL, NULL);
 	if (sockd < 0) {
 		if (interrupted())
@@ -935,19 +935,15 @@ retry:
 		goto out;
 	} else if (!strncasecmp(buf, "update", 6)) {
 		update_base(ckp);
-		goto reset;
 	} else if (!strncasecmp(buf, "subscribe", 9)) {
 		/* Proxifier has a new subscription */
 		if (!update_subscribe(ckp))
 			goto out;
-		goto retry;
 	} else if (!strncasecmp(buf, "notify", 6)) {
 		/* Proxifier has a new notify ready */
 		update_notify(ckp);
-		goto retry;
 	} else if (!strncasecmp(buf, "diff", 4)) {
 		update_diff(ckp);
-		goto retry;
 	} else if (!strncasecmp(buf, "dropclient", 10)) {
 		int client_id;
 
@@ -956,11 +952,9 @@ retry:
 			LOGDEBUG("Stratifier failed to parse dropclient command: %s", buf);
 		else
 			drop_client(client_id);
-		goto retry;
 	} else if (!strncasecmp(buf, "block", 5)) {
 		block_solve(ckp);
 		update_base(ckp);
-		goto reset;
 	} else {
 		json_t *val = json_loads(buf, 0, NULL);
 
@@ -968,8 +962,8 @@ retry:
 			LOGWARNING("Received unrecognised message: %s", buf);
 		}  else
 			stratum_add_recvd(val);
-		goto retry;
 	}
+	goto retry;
 
 out:
 	dealloc(buf);