Add lock_timeout configuration parameter.

This GUC allows limiting the time spent waiting to acquire any one
heavyweight lock.

In support of this, improve the recently-added timeout infrastructure
to permit efficiently enabling or disabling multiple timeouts at once.
That reduces the performance hit from turning on lock_timeout, though
it's still not zero.

Zoltán Böszörményi, reviewed by Tom Lane,
Stephen Frost, and Hari Babu

1 files changed, 18 insertions, 0 deletions

diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 84270061d8a..5f8f98b5e03 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -67,6 +67,7 @@ static void CheckMyDatabase(const char *name, bool am_superuser);
 static void InitCommunication(void);
 static void ShutdownPostgres(int code, Datum arg);
 static void StatementTimeoutHandler(void);
+static void LockTimeoutHandler(void);
 static bool ThereIsAtLeastOneRole(void);
 static void process_startup_options(Port *port, bool am_superuser);
 static void process_settings(Oid databaseid, Oid roleid);
@@ -535,6 +536,7 @@ InitPostgres(const char *in_dbname, Oid dboid, const char *username,
 	{
 		RegisterTimeout(DEADLOCK_TIMEOUT, CheckDeadLock);
 		RegisterTimeout(STATEMENT_TIMEOUT, StatementTimeoutHandler);
+		RegisterTimeout(LOCK_TIMEOUT, LockTimeoutHandler);
 	}
 
 	/*
@@ -1052,6 +1054,22 @@ StatementTimeoutHandler(void)
 	kill(MyProcPid, SIGINT);
 }
 
+/*
+ * LOCK_TIMEOUT handler: trigger a query-cancel interrupt.
+ *
+ * This is identical to StatementTimeoutHandler, but since it's so short,
+ * we might as well keep the two functions separate for clarity.
+ */
+static void
+LockTimeoutHandler(void)
+{
+#ifdef HAVE_SETSID
+	/* try to signal whole process group */
+	kill(-MyProcPid, SIGINT);
+#endif
+	kill(MyProcPid, SIGINT);
+}
+
 
 /*
  * Returns true if at least one role is defined in this database cluster.