From 83a465a4c847f32bcf71ac8e759c7f6b6a3de099 Mon Sep 17 00:00:00 2001
From: Yoshiyuki Asaba <y-asaba at pgfoundry.org>
Date: Wed, 20 Jun 2007 08:23:26 +0000
Subject: [PATCH] Fix signal handling for failover. Failover operation is
 executed in signal safe places.

---
 main.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/main.c b/main.c
index 81992b4..5d8fc9f 100644
--- a/main.c
+++ b/main.c
@@ -46,6 +46,16 @@
 
 #include "version.h"
 
+#define CHECK_FAILOVER_REQUEST \
+	do \
+	{ \
+		if (failover_request) \
+		{ \
+			failover(failover_request); \
+			failover_request = 0; \
+		} \
+	} while (0)
+
 #define PGPOOLMAXLITSENQUEUELENGTH 10000
 static void daemonize(void);
 static int read_pid_file(void);
@@ -54,6 +64,7 @@ static pid_t fork_a_child(int unix_fd, int inet_fd);
 static int create_unix_domain_socket(void);
 static int create_inet_domain_socket(const char *hostname);
 static void myexit(int code);
+static void failover(int sig);
 
 static RETSIGTYPE exit_handler(int sig);
 static RETSIGTYPE reap_handler(int sig);
@@ -86,6 +97,7 @@ static int stop_sig = SIGTERM;	/* stopping signal default value */
 static int switch_over_sig = SIGUSR1;	/* switch over signal default value */
 
 static int health_check_timer_expired;		/* non 0 if health check timer expired */
+static volatile int failover_request = 0;
 
 int myargc;
 char **myargv;
@@ -311,6 +323,8 @@ int main(int argc, char **argv)
 	 */
 	for (;;)
 	{
+		CHECK_FAILOVER_REQUEST;
+
 		/* do we need health checking for PostgreSQL? */
 		if (!degenerated && pool_config.health_check_period > 0)
 		{
@@ -341,11 +355,11 @@ int main(int argc, char **argv)
 			{
 				if (sts == -1)
 				{
-					failover_handler(SIGUSR1);		/* master down */
+					failover(SIGUSR1);		/* master down */
 				}
 				else if (sts == -2)
 				{
-					failover_handler(SIGUSR2);		/* secondary down */
+					failover(SIGUSR2);		/* secondary down */
 				}
 			}
 
@@ -359,6 +373,7 @@ int main(int argc, char **argv)
 			while (sleep_time > 0)
 			{
 				sleep_time = sleep(sleep_time);
+				CHECK_FAILOVER_REQUEST;
 			}
 		}
 		else
@@ -753,7 +768,6 @@ static RETSIGTYPE exit_handler(int sig)
 	myexit(0);
 }
 
-
 /*
  * handle SIGUSR1/SIGUSR2 (backend connection error, fail over request, if possible)
  *
@@ -761,6 +775,14 @@ static RETSIGTYPE exit_handler(int sig)
  * if sig == SIGUSR2, we assume that the secondary has been down.
  */
 static RETSIGTYPE failover_handler(int sig)
+{
+	failover_request = sig;
+}
+
+/*
+ * Process failover request
+ */
+static void failover(int sig)
 {
 	int i;
 	int replication = 0;
-- 
2.39.5