Some comments about GUCs.

Alexander Korotkov · Alexander Korotkov · commit 60ba74231ed2 · 2016-05-13T11:35:22.000+03:00
diff --git a/contrib/pg_stat_wait/pg_stat_wait.c b/contrib/pg_stat_wait/pg_stat_wait.c
@@ -136,6 +136,9 @@ typedef union
 	struct config_enum _enum;
 } mixedStruct;
 
+/*
+ * Set or reset history GUCs in shared memory.
+ */
 static void
 set_history_gucs()
 {
@@ -149,6 +152,7 @@ set_history_gucs()
 	guc_vars = get_guc_variables();
 	numOpts = GetNumConfigOptions();
 
+	/* Change pointers in already defined GUCs */
 	for (i = 0; i < numOpts; i++)
 	{
 		mixedStruct *var = (mixedStruct *) guc_vars[i];
@@ -177,6 +181,7 @@ set_history_gucs()
 		}
 	}
 
+	/* Define undefined GUCs */
 	if (!history_size_found)
 		DefineCustomIntVariable("pg_stat_wait.history_size",
 				"Sets size of waits history.", NULL,
@@ -198,6 +203,7 @@ set_history_gucs()
 				PGC_SUSET, 0,
 				shmem_bool_guc_check_hook, NULL, NULL);
 
+	/* Re-read config for already defined GUCs which values are missed */
 	if (history_size_found || history_period_found || history_skip_latch_found)
 		ProcessConfigFile(PGC_SIGHUP);
 }

Original file line number	Diff line number	Diff line change
`@@ -136,6 +136,9 @@ typedef union`
`136`	`136`	`struct config_enum _enum;`
`137`	`137`	`} mixedStruct;`
`138`	`138`
	`139`	`+/*`
	`140`	`+ * Set or reset history GUCs in shared memory.`
	`141`	`+ */`
`139`	`142`	`static void`
`140`	`143`	`set_history_gucs()`
`141`	`144`	`{`
`@@ -149,6 +152,7 @@ set_history_gucs()`
`149`	`152`	`guc_vars = get_guc_variables();`
`150`	`153`	`numOpts = GetNumConfigOptions();`
`151`	`154`
	`155`	`+ /* Change pointers in already defined GUCs */`
`152`	`156`	`for (i = 0; i < numOpts; i++)`
`153`	`157`	`{`
`154`	`158`	`mixedStruct var = (mixedStruct ) guc_vars[i];`
`@@ -177,6 +181,7 @@ set_history_gucs()`
`177`	`181`	`}`
`178`	`182`	`}`
`179`	`183`
	`184`	`+ /* Define undefined GUCs */`
`180`	`185`	`if (!history_size_found)`
`181`	`186`	`DefineCustomIntVariable("pg_stat_wait.history_size",`
`182`	`187`	`"Sets size of waits history.", NULL,`
`@@ -198,6 +203,7 @@ set_history_gucs()`
`198`	`203`	`PGC_SUSET, 0,`
`199`	`204`	`shmem_bool_guc_check_hook, NULL, NULL);`
`200`	`205`
	`206`	`+ /* Re-read config for already defined GUCs which values are missed */`
`201`	`207`	`if (history_size_found \|\| history_period_found \|\| history_skip_latch_found)`
`202`	`208`	`ProcessConfigFile(PGC_SIGHUP);`
`203`	`209`	`}`