pgpool2.git / summary / log / commit / refs

commit    e18632ebed7069243d919293cc4e3aa760c3d91a
Author:   Tatsuo Ishii <ishii@postgresql.org>
Date:     Fri Sep 22 01:51:45 2017 +0000

    Fix exit signal handlers to not call ereport.
    
    There could be a race condition in the exit signal handlers. While
    ereport is called in the handler, other interruption could call
    ereport again. If ereport calls tz_convert which tries to acquire a
    lock, it goes into a deadlock situation. In other word, tz_convert is
    not reentrant and should not be used in signal handlers. So I removed
    all ereport calls from exit signal handlers.
    
    BTW pcp main calls ereport before the exception handler is
    established. This could cause problem of course. So I fixed this
    together. See [pgpool-hackers: 2545] for more details.


 src/main/pgpool_main.c  | 29 ++---------------------------
 src/pcp_con/pcp_child.c | 24 ++++--------------------
 2 files changed, 6 insertions(+), 47 deletions(-)

diff --git a/src/main/pgpool_main.c b/src/main/pgpool_main.c
index 1f3dab372..cb3bac54e 100644
--- a/src/main/pgpool_main.c
+++ b/src/main/pgpool_main.c
@@ -1302,6 +1302,7 @@ static RETSIGTYPE exit_handler(int sig)
 {
 	int i;
     pid_t wpid;
+	int *walk;
 
 	int save_errno = errno;
 	POOL_SETMASK(&AuthBlockSig);
@@ -1312,28 +1313,12 @@ static RETSIGTYPE exit_handler(int sig)
 	 */
 	if (getpid() != mypid)
 	{
-		ereport(DEBUG1,
-			(errmsg("exit_handler: I am not parent")));
-
 		POOL_SETMASK(&UnBlockSig);
 		proc_exit(0);
 	}
 
-	if (sig == SIGTERM)
-		ereport(LOG,
-                (errmsg("received smart shutdown request")));
-	else if (sig == SIGINT)
-		ereport(LOG,
-                (errmsg("received fast shutdown request")));
-	else if (sig == SIGQUIT)
-		ereport(LOG,
-                (errmsg("received immediate shutdown request")));
-	else
+	if (sig != SIGTERM && sig != SIGINT && sig != SIGQUIT)
 	{
-		ereport(LOG,
-			(errmsg("main process received unknown signal: %d",sig),
-				 errdetail("ignoring...")));
-
 		POOL_SETMASK(&UnBlockSig);
 		errno = save_errno;
 		return;
@@ -1342,10 +1327,6 @@ static RETSIGTYPE exit_handler(int sig)
     processState = EXITING;
 
     /* Close listen socket */
-	ereport(LOG,
-		(errmsg("shutdown request. closing listen socket")));
-
-	int *walk;
 	for (walk = fds; *walk != -1; walk++)
 		close(*walk);
 
@@ -1394,14 +1375,8 @@ static RETSIGTYPE exit_handler(int sig)
         wpid = waitpid(-1, &ret_pid, 0);
     } while (wpid > 0 || (wpid == -1 && errno == EINTR));
 
-    if (wpid == -1 && errno != ECHILD)
-        ereport(LOG,
-                (errmsg("wait() failed. reason:%s", strerror(errno))));
-
 	process_info = NULL;
 	exit(0);
-
-	errno = save_errno;
 }
 
 /*
diff --git a/src/pcp_con/pcp_child.c b/src/pcp_con/pcp_child.c
index fbabdc5bf..5c919fbfb 100644
--- a/src/pcp_con/pcp_child.c
+++ b/src/pcp_con/pcp_child.c
@@ -101,9 +101,6 @@ void pcp_main(int unix_fd, int inet_fd)
 	sigjmp_buf	local_sigjmp_buf;
 	struct timeval uptime;
 
-	ereport(DEBUG1,
-			(errmsg("I am PCP child with pid:%d",getpid())));
-
 	/* Identify myself via ps */
 	init_ps_display("", "", "", "");
 
@@ -143,6 +140,10 @@ void pcp_main(int unix_fd, int inet_fd)
 	}
 	/* We can now handle ereport(ERROR) */
 	PG_exception_stack = &local_sigjmp_buf;
+
+	ereport(DEBUG1,
+			(errmsg("I am PCP child with pid:%d",getpid())));
+
 	for(;;)
 	{
 		int port;
@@ -354,29 +355,15 @@ pcp_exit_handler(int sig)
 	pid_t wpid;
 
 	POOL_SETMASK(&AuthBlockSig);
-	ereport(DEBUG1,
-			(errmsg("PCP child receives shutdown request signal %d, Forwarding to all children", sig)));
 
 	pcp_kill_all_children(sig);
 
 	if (sig == SIGTERM) /* smart shutdown */
 	{
-		ereport(DEBUG1,
-				(errmsg("PCP child receives smart shutdown request")));
 		/* close the listening sockets */
 		close(pcp_unix_fd);
 		close(pcp_inet_fd);
 	}
-	else if (sig == SIGINT)
-	{
-		ereport(DEBUG1,
-				(errmsg("PCP child receives fast shutdown request")));
-	}
-	else if (sig == SIGQUIT)
-	{
-		ereport(DEBUG1,
-				(errmsg("PCP child receives immediate shutdown request")));
-	}
 
 	POOL_SETMASK(&UnBlockSig);
 
@@ -387,9 +374,6 @@ pcp_exit_handler(int sig)
 			wpid = wait(NULL);
 		}while (wpid > 0 || (wpid == -1 && errno == EINTR));
 		
-		if (wpid == -1 && errno != ECHILD)
-			ereport(WARNING,
-					(errmsg("wait() on pcp worker children failed. reason:%s", strerror(errno))));
 		list_free(pcp_worker_children);
 	}
 	pcp_worker_children = NULL;


[parent: 3cc5235a4c9b]