pgpool2.git / summary / log / commit / refs

commit    d3850a02cc478f62df74e2f629faa8444047fe0c
Author:   Tatsuo Ishii <ishii at sraoss.co.jp>
Date:     Sun Sep 06 03:56:37 2009 +0000

    Fix connection_count_down() so that it does decrement too much in some
    corner cases.  If failed to read a start up packet, or receive cancel
    request etc., connection_count_down() is called and goes back to the
    onnection accept loop. Problem is, at the very beginning of the
    connection accept loop, if we have received a signal, we call
    child_exit() which calls connection_count_down() again.
    Problem report by Ryoichi TANABE. See [pgpool-general-jp: 616]
    for more details.
    
    Also unneccesary public declarations for connection_count_up() and
    connection_count_down() are removed.


 child.c | 25 ++++++++++++++++++++++---
 pool.h  |  3 ---
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/child.c b/child.c
index 788ffc7dc..eeb150c66 100644
--- a/child.c
+++ b/child.c
@@ -68,6 +68,8 @@ static RETSIGTYPE authentication_timeout(int sig);
 static int send_params(POOL_CONNECTION *frontend, POOL_CONNECTION_POOL *backend);
 static void send_frontend_exits(void);
 static int s_do_auth(POOL_CONNECTION_POOL_SLOT *cp, char *password);
+static void connection_count_up(void);
+static void connection_count_down(void);
 
 /*
  * non 0 means SIGTERM(smart shutdown) or SIGINT(fast shutdown) has arrived
@@ -1774,17 +1776,34 @@ static int s_do_auth(POOL_CONNECTION_POOL_SLOT *cp, char *password)
 	return -1;
 }
 
-void connection_count_up(void)
+/*
+ * Count up connection counter (from frontend to pgpool)
+ * in shared memory
+ */
+static void connection_count_up(void)
 {
 	pool_semaphore_lock(CONN_COUNTER_SEM);
 	Req_info->conn_counter++;
 	pool_semaphore_unlock(CONN_COUNTER_SEM);
 }
 
-void connection_count_down(void)
+/*
+ * Count down connection counter (from frontend to pgpool)
+ * in shared memory
+ */
+static void connection_count_down(void)
 {
 	pool_semaphore_lock(CONN_COUNTER_SEM);
-	Req_info->conn_counter--;
+	/*
+	 * Make sure that we do not decrement too much.  If failed to read
+	 * a start up packet, or receive cancel request etc.,
+	 * connection_count_down() is called and goes back to the
+	 * connection accept loop. Problem is, at the very beginning of
+	 * the connection accept loop, if we have received a signal, we
+	 * call child_exit() which calls connection_count_down() again.
+	 */
+	if (Req_info->conn_counter > 0)
+		Req_info->conn_counter--;
 	pool_semaphore_unlock(CONN_COUNTER_SEM);
 }
 
diff --git a/pool.h b/pool.h
index 290eb4f9b..e2458bb7c 100644
--- a/pool.h
+++ b/pool.h
@@ -528,9 +528,6 @@ extern int send_startup_packet(POOL_CONNECTION_POOL_SLOT *cp);
 extern void pool_free_startup_packet(StartupPacket *sp);
 extern void child_exit(int code);
 
-extern void connection_count_up(void);
-extern void connection_count_down(void);
-
 extern int health_check(void);
 extern int system_db_health_check(void);
 


[parent: d782bc549321]