SIGALRM handler didn't safe. Because it called non-reentrant functions.

We only set a flag in SIGALRM handler. Then we close expired
connections in safe places.

3 files changed, 37 insertions, 2 deletions

diff --git a/child.c b/child.c
index 3cc6398..3da7728 100644
--- a/child.c
+++ b/child.c
@@ -177,6 +177,13 @@ void do_child(int unix_fd, int inet_fd)
 		idle = 0;
 		child_idle_sec = 0;
 
+		/* check backend timer is expired */
+		if (backend_timer_expired)
+		{
+			pool_backend_timer();
+			backend_timer_expired = 0;
+		}
+
 		/* disable timeout */
 		pool_disable_timeout();
 
@@ -524,6 +531,7 @@ static POOL_CONNECTION *do_accept(int unix_fd, int inet_fd, struct timeval *time
 {
     fd_set	readmask;
     int fds;
+	int save_errno;
 
 	SockAddr saddr;
 	int fd = 0;
@@ -565,6 +573,14 @@ static POOL_CONNECTION *do_accept(int unix_fd, int inet_fd, struct timeval *time
 
 	fds = select(Max(unix_fd, inet_fd)+1, &readmask, NULL, NULL, timeoutval);
 
+	save_errno = errno;
+	/* check backend timer is expired */
+	if (backend_timer_expired)
+	{
+		pool_backend_timer();
+		backend_timer_expired = 0;
+	}
+
 	/*
 	 * following code fragment computes remaining timeout val in a
 	 * portable way. Linux does this automazically but other platforms do not.
@@ -597,6 +613,8 @@ static POOL_CONNECTION *do_accept(int unix_fd, int inet_fd, struct timeval *time
 #endif
 	}
 
+	errno = save_errno;
+
 	if (fds == -1)
 	{
 		if (errno == EAGAIN || errno == EINTR)
@@ -634,13 +652,22 @@ static POOL_CONNECTION *do_accept(int unix_fd, int inet_fd, struct timeval *time
 	gettimeofday(&now1,0);
 #endif
 	afd = accept(fd, (struct sockaddr *)&saddr.addr, &saddr.salen);
+
+	save_errno = errno;
+	/* check backend timer is expired */
+	if (backend_timer_expired)
+	{
+		pool_backend_timer();
+		backend_timer_expired = 0;
+	}
+	errno = save_errno;
 	if (afd < 0)
 	{
 		/*
 		 * "Resource temporarily unavailable" (EAGAIN or EWOULDBLOCK)
-		 * can be silently ignored.
+		 * can be silently ignored. And EINTR can be ignored
 		 */
-		if (errno != EAGAIN && errno != EWOULDBLOCK)
+		if (errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR)
 			pool_error("accept() failed. reason: %s", strerror(errno));
 		return NULL;
 	}
diff --git a/pool.h b/pool.h
index cf84131..d1e77d3 100644
--- a/pool.h
+++ b/pool.h
@@ -277,6 +277,7 @@ typedef struct {
  */
 extern POOL_CONFIG pool_config;	/* configuration values */
 extern POOL_CONNECTION_POOL *pool_connection_pool;	/* connection pool */
+extern volatile sig_atomic_t backend_timer_expired;
 extern long int weight_master;	/* normalized weight of master (0-RAND_MAX range) */
 extern char remote_ps_data[];		/* used for set_ps_display */
 
@@ -312,6 +313,7 @@ extern int pool_init_cp(void);
 extern POOL_CONNECTION_POOL *pool_create_cp(void);
 extern POOL_CONNECTION_POOL *pool_get_cp(char *user, char *database, int protoMajor, int check_socket);
 extern void pool_discard_cp(char *user, char *database, int protoMajor);
+extern void pool_backend_timer(void);
 
 extern POOL_STATUS ErrorResponse(POOL_CONNECTION *frontend, 
 								  POOL_CONNECTION_POOL *backend);
diff --git a/pool_connection_pool.c b/pool_connection_pool.c
index ceb801e..8195678 100644
--- a/pool_connection_pool.c
+++ b/pool_connection_pool.c
@@ -41,6 +41,7 @@
 #include "pool.h"
 
 POOL_CONNECTION_POOL *pool_connection_pool;	/* connection pool */
+volatile sig_atomic_t backend_timer_expired = 0;
 
 static POOL_CONNECTION_POOL_SLOT *create_cp(POOL_CONNECTION_POOL_SLOT *cp, int secondary_backend);
 static POOL_CONNECTION_POOL *new_connection(POOL_CONNECTION_POOL *p);
@@ -258,6 +259,11 @@ void pool_connection_pool_timer(POOL_CONNECTION_POOL *backend)
  */
 RETSIGTYPE pool_backend_timer_handler(int sig)
 {
+	backend_timer_expired = 1;
+}
+
+void pool_backend_timer(void)
+{
 #define TMINTMAX 0x7fffffff
 
 	POOL_CONNECTION_POOL *p = pool_connection_pool;