pgpool2.git / summary / log / commit / refs

commit    c2d464521ef017fd7aa76fc56c412c5af06fdb07
Author:   Tatsuo Ishii <ishii@postgresql.org>
Date:     Tue Jul 21 11:47:11 2026 +0000

    Add volatile qualifier.
    
    In Pgpool-II main, local pointer array "my_backend_status" is not
    volatile qualified, while it should have been.
    Also in initialize_shared_mem_objects() and sync_backend_from_watchdog():
    
    	my_backend_status[i] = &(BACKEND_INFO(i).backend_status);
    
    should have been:
    
    	my_backend_status[i] = (volatile BACKEND_STATUS *) &(BACKEND_INFO(i).backend_status);
    
    Without these volatile qualifiers, *(my_backend_status[i]) could read
    state value because of compiler optimization. Since
    my_backend_status[i] is referred to in popular VALID_BACKEND macro, we
    should fix it in all supported branches.
    
    Author: Tatsuo Ishii <ishii@postgresql.org>
    Discussion: https://www.postgresql.org/message-id/20260701.101148.451717746326656928.ishii%40postgresql.org
    Backpatch-through: v4.3


 src/include/pool.h     |  2 +-
 src/main/pgpool_main.c | 13 +++++++++----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/include/pool.h b/src/include/pool.h
index 549aed30f..ef0876c84 100644
--- a/src/include/pool.h
+++ b/src/include/pool.h
@@ -345,7 +345,7 @@ extern int	pool_get_major_version(void);
 extern bool pool_is_node_to_be_sent_in_current_query(int node_id);
 extern int	pool_virtual_main_db_node_id(void);
 
-extern BACKEND_STATUS *my_backend_status[];
+extern volatile BACKEND_STATUS *my_backend_status[];
 extern int	my_main_node_id;
 
 #define VALID_BACKEND(backend_id) \
diff --git a/src/main/pgpool_main.c b/src/main/pgpool_main.c
index 19d89cb79..14d238003 100644
--- a/src/main/pgpool_main.c
+++ b/src/main/pgpool_main.c
@@ -277,7 +277,9 @@ static pid_t pgpool_logger_pid = 0; /* pid for pgpool_logger process */
 static pid_t wd_lifecheck_pid = 0;	/* pid for child process handling watchdog
 									 * lifecheck */
 
-BACKEND_STATUS *my_backend_status[MAX_NUM_BACKENDS];	/* Backend status buffer */
+/* Backend status buffer */
+volatile BACKEND_STATUS *my_backend_status[MAX_NUM_BACKENDS];
+
 int			my_main_node_id;	/* Main node id buffer */
 
 /*
@@ -3220,7 +3222,8 @@ initialize_shared_mem_objects(bool clear_memcache_oidmaps)
 
 	for (i = 0; i < MAX_NUM_BACKENDS; i++)
 	{
-		my_backend_status[i] = &(BACKEND_INFO(i).backend_status);
+		my_backend_status[i] =
+			(volatile BACKEND_STATUS *) &(BACKEND_INFO(i).backend_status);
 	}
 
 	/* initialize Req_info */
@@ -3783,7 +3786,8 @@ sync_backend_from_watchdog(void)
 			{
 				BACKEND_INFO(i).backend_status = CON_DOWN;
 				pool_set_backend_status_changed_time(i);
-				my_backend_status[i] = &(BACKEND_INFO(i).backend_status);
+				my_backend_status[i] =
+					(volatile BACKEND_STATUS *) &(BACKEND_INFO(i).backend_status);
 				reload_master_node_id = true;
 				node_status_was_changed_to_down = true;
 				ereport(LOG,
@@ -3802,7 +3806,8 @@ sync_backend_from_watchdog(void)
 
 				BACKEND_INFO(i).backend_status = CON_CONNECT_WAIT;
 				pool_set_backend_status_changed_time(i);
-				my_backend_status[i] = &(BACKEND_INFO(i).backend_status);
+				my_backend_status[i] =
+					(volatile BACKEND_STATUS *) &(BACKEND_INFO(i).backend_status);
 				reload_master_node_id = true;
 
 				ereport(LOG,


[parent: ec0e059cd14a]