Reserver NUM_EXTRA_SEMAPHORES for multimaster

Author: knizhnik

src/backend/storage/lmgr/proc.c

@@ -130,7 +130,7 @@ ProcGlobalSemas(void)
 	 * We need a sema per backend (including autovacuum), plus one for each
 	 * auxiliary process.
 	 */
-	return MaxBackends + NUM_AUXILIARY_PROCS;
+	return MaxBackends + NUM_AUXILIARY_PROCS + NUM_EXTRA_SEMAPHORES;
 }
 
 /*

src/include/storage/proc.h

@@ -260,6 +260,10 @@ extern PGPROC *PreparedXactProcs;
  */
 #define NUM_AUXILIARY_PROCS		4
 
+/*
+ * Number of extra semaphores used by Postgres (right now 3 semaphores are used by multimaster)
+ */
+#define NUM_EXTRA_SEMAPHORES    4
 
 /* configurable options */
 extern int	PGDLLIMPORT DeadlockTimeout;