Register atexit hook only once in pg_upgrade.

tglsfdc · tglsfdc · commit 93b99d3b6aec · 2016-07-28T11:39:10.000-04:00
start_postmaster() registered stop_postmaster_atexit as an atexit(3)
callback each time through, although the obvious intention was to do
so only once per program run.  The extra registrations were harmless,
so long as we didn't exceed ATEXIT_MAX, but still it's a bug.

Artur Zakirov, with bikeshedding by Kyotaro Horiguchi and me

Discussion: &lt;d279e817-02b5-caa6-215f-cfb05dce109a@postgrespro.ru&gt;
diff --git a/src/bin/pg_upgrade/server.c b/src/bin/pg_upgrade/server.c
@@ -174,10 +174,11 @@ start_postmaster(ClusterInfo *cluster, bool throw_error)
 {
 	char		cmd[MAXPGPATH * 4 + 1000];
 	PGconn	   *conn;
-	bool		exit_hook_registered = false;
 	bool		pg_ctl_return = false;
 	char		socket_string[MAXPGPATH + 200];
 
+	static bool exit_hook_registered = false;
+
 	if (!exit_hook_registered)
 	{
 		atexit(stop_postmaster_atexit);

Original file line number	Diff line number	Diff line change
`@@ -174,10 +174,11 @@ start_postmaster(ClusterInfo *cluster, bool throw_error)`
`174`	`174`	`{`
`175`	`175`	`char cmd[MAXPGPATH * 4 + 1000];`
`176`	`176`	`PGconn *conn;`
`177`		`- bool exit_hook_registered = false;`
`178`	`177`	`bool pg_ctl_return = false;`
`179`	`178`	`char socket_string[MAXPGPATH + 200];`
`180`	`179`
	`180`	`+ static bool exit_hook_registered = false;`
	`181`	`+`
`181`	`182`	`if (!exit_hook_registered)`
`182`	`183`	`{`
`183`	`184`	`atexit(stop_postmaster_atexit);`