Add idle_session_timeout.

This GUC variable works much like idle_in_transaction_session_timeout,
in that it kills sessions that have waited too long for a new client
query.  But it applies when we're not in a transaction, rather than
when we are.

Li Japin, reviewed by David Johnston and Hayato Kuroda, some
fixes by me

Discussion: https://postgr.es/m/763A0689-F189-459E-946F-F0EC4458980B@hotmail.com

1 files changed, 41 insertions, 7 deletions

diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 9d98c028a2d..2b53ebf97dc 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3242,14 +3242,28 @@ ProcessInterrupts(void)
 
 	if (IdleInTransactionSessionTimeoutPending)
 	{
-		/* Has the timeout setting changed since last we looked? */
+		/*
+		 * If the GUC has been reset to zero, ignore the signal.  This is
+		 * important because the GUC update itself won't disable any pending
+		 * interrupt.
+		 */
 		if (IdleInTransactionSessionTimeout > 0)
 			ereport(FATAL,
 					(errcode(ERRCODE_IDLE_IN_TRANSACTION_SESSION_TIMEOUT),
 					 errmsg("terminating connection due to idle-in-transaction timeout")));
 		else
 			IdleInTransactionSessionTimeoutPending = false;
+	}
 
+	if (IdleSessionTimeoutPending)
+	{
+		/* As above, ignore the signal if the GUC has been reset to zero. */
+		if (IdleSessionTimeout > 0)
+			ereport(FATAL,
+					(errcode(ERRCODE_IDLE_SESSION_TIMEOUT),
+					 errmsg("terminating connection due to idle-session timeout")));
+		else
+			IdleSessionTimeoutPending = false;
 	}
 
 	if (ProcSignalBarrierPending)
@@ -3826,7 +3840,8 @@ PostgresMain(int argc, char *argv[],
 	StringInfoData input_message;
 	sigjmp_buf	local_sigjmp_buf;
 	volatile bool send_ready_for_query = true;
-	bool		disable_idle_in_transaction_timeout = false;
+	bool		idle_in_transaction_timeout_enabled = false;
+	bool		idle_session_timeout_enabled = false;
 
 	/* Initialize startup process environment if necessary. */
 	if (!IsUnderPostmaster)
@@ -4228,6 +4243,8 @@ PostgresMain(int argc, char *argv[],
 		 * processing of batched messages, and because we don't want to report
 		 * uncommitted updates (that confuses autovacuum).  The notification
 		 * processor wants a call too, if we are not in a transaction block.
+		 *
+		 * Also, if an idle timeout is enabled, start the timer for that.
 		 */
 		if (send_ready_for_query)
 		{
@@ -4239,7 +4256,7 @@ PostgresMain(int argc, char *argv[],
 				/* Start the idle-in-transaction timer */
 				if (IdleInTransactionSessionTimeout > 0)
 				{
-					disable_idle_in_transaction_timeout = true;
+					idle_in_transaction_timeout_enabled = true;
 					enable_timeout_after(IDLE_IN_TRANSACTION_SESSION_TIMEOUT,
 										 IdleInTransactionSessionTimeout);
 				}
@@ -4252,7 +4269,7 @@ PostgresMain(int argc, char *argv[],
 				/* Start the idle-in-transaction timer */
 				if (IdleInTransactionSessionTimeout > 0)
 				{
-					disable_idle_in_transaction_timeout = true;
+					idle_in_transaction_timeout_enabled = true;
 					enable_timeout_after(IDLE_IN_TRANSACTION_SESSION_TIMEOUT,
 										 IdleInTransactionSessionTimeout);
 				}
@@ -4275,6 +4292,14 @@ PostgresMain(int argc, char *argv[],
 
 				set_ps_display("idle");
 				pgstat_report_activity(STATE_IDLE, NULL);
+
+				/* Start the idle-session timer */
+				if (IdleSessionTimeout > 0)
+				{
+					idle_session_timeout_enabled = true;
+					enable_timeout_after(IDLE_SESSION_TIMEOUT,
+										 IdleSessionTimeout);
+				}
 			}
 
 			/* Report any recently-changed GUC options */
@@ -4310,12 +4335,21 @@ PostgresMain(int argc, char *argv[],
 		DoingCommandRead = false;
 
 		/*
-		 * (5) turn off the idle-in-transaction timeout
+		 * (5) turn off the idle-in-transaction and idle-session timeouts, if
+		 * active.
+		 *
+		 * At most one of these two will be active, so there's no need to
+		 * worry about combining the timeout.c calls into one.
 		 */
-		if (disable_idle_in_transaction_timeout)
+		if (idle_in_transaction_timeout_enabled)
 		{
 			disable_timeout(IDLE_IN_TRANSACTION_SESSION_TIMEOUT, false);
-			disable_idle_in_transaction_timeout = false;
+			idle_in_transaction_timeout_enabled = false;
+		}
+		if (idle_session_timeout_enabled)
+		{
+			disable_timeout(IDLE_SESSION_TIMEOUT, false);
+			idle_session_timeout_enabled = false;
 		}
 
 		/*