4 files changed, 43 insertions, 0 deletions

diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 73e0a672ae3..a9f0fc3017c 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -30,6 +30,7 @@ ProtocolVersion FrontendProtocol;
 volatile sig_atomic_t InterruptPending = false;
 volatile sig_atomic_t QueryCancelPending = false;
 volatile sig_atomic_t ProcDiePending = false;
+volatile sig_atomic_t CheckClientConnectionPending = false;
 volatile sig_atomic_t ClientConnectionLost = false;
 volatile sig_atomic_t IdleInTransactionSessionTimeoutPending = false;
 volatile sig_atomic_t IdleSessionTimeoutPending = false;
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 7abeccb5362..a3ec358538a 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -73,6 +73,7 @@ static void StatementTimeoutHandler(void);
 static void LockTimeoutHandler(void);
 static void IdleInTransactionSessionTimeoutHandler(void);
 static void IdleSessionTimeoutHandler(void);
+static void ClientCheckTimeoutHandler(void);
 static bool ThereIsAtLeastOneRole(void);
 static void process_startup_options(Port *port, bool am_superuser);
 static void process_settings(Oid databaseid, Oid roleid);
@@ -620,6 +621,7 @@ InitPostgres(const char *in_dbname, Oid dboid, const char *username,
 		RegisterTimeout(IDLE_IN_TRANSACTION_SESSION_TIMEOUT,
 						IdleInTransactionSessionTimeoutHandler);
 		RegisterTimeout(IDLE_SESSION_TIMEOUT, IdleSessionTimeoutHandler);
+		RegisterTimeout(CLIENT_CONNECTION_CHECK_TIMEOUT, ClientCheckTimeoutHandler);
 	}
 
 	/*
@@ -1242,6 +1244,14 @@ IdleSessionTimeoutHandler(void)
 	SetLatch(MyLatch);
 }
 
+static void
+ClientCheckTimeoutHandler(void)
+{
+	CheckClientConnectionPending = true;
+	InterruptPending = true;
+	SetLatch(MyLatch);
+}
+
 /*
  * Returns true if at least one role is defined in this database cluster.
  */
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 584daffc8a9..60a9c7a2a0b 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -20,6 +20,9 @@
 #include <float.h>
 #include <math.h>
 #include <limits.h>
+#ifdef HAVE_POLL_H
+#include <poll.h>
+#endif
 #ifndef WIN32
 #include <sys/mman.h>
 #endif
@@ -204,6 +207,7 @@ static bool check_autovacuum_work_mem(int *newval, void **extra, GucSource sourc
 static bool check_effective_io_concurrency(int *newval, void **extra, GucSource source);
 static bool check_maintenance_io_concurrency(int *newval, void **extra, GucSource source);
 static bool check_huge_page_size(int *newval, void **extra, GucSource source);
+static bool check_client_connection_check_interval(int *newval, void **extra, GucSource source);
 static void assign_pgstat_temp_directory(const char *newval, void *extra);
 static bool check_application_name(char **newval, void **extra, GucSource source);
 static void assign_application_name(const char *newval, void *extra);
@@ -3501,6 +3505,17 @@ static struct config_int ConfigureNamesInt[] =
 		NULL, NULL, NULL
 	},
 
+	{
+		{"client_connection_check_interval", PGC_USERSET, CLIENT_CONN_OTHER,
+			gettext_noop("Sets the time interval between checks for disconnection while running queries."),
+			NULL,
+			GUC_UNIT_MS
+		},
+		&client_connection_check_interval,
+		0, 0, INT_MAX,
+		check_client_connection_check_interval, NULL, NULL
+	},
+
 	/* End-of-list marker */
 	{
 		{NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL
@@ -11980,6 +11995,20 @@ check_huge_page_size(int *newval, void **extra, GucSource source)
 	return true;
 }
 
+static bool
+check_client_connection_check_interval(int *newval, void **extra, GucSource source)
+{
+#ifndef POLLRDHUP
+	/* Linux only, for now.  See pq_check_connection(). */
+	if (*newval != 0)
+	{
+		GUC_check_errdetail("client_connection_check_interval must be set to 0 on platforms that lack POLLRDHUP.");
+		return false;
+	}
+#endif
+	return true;
+}
+
 static void
 assign_pgstat_temp_directory(const char *newval, void *extra)
 {
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 30cfddac1f7..39da7cc9427 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -719,6 +719,9 @@
 
 #dynamic_library_path = '$libdir'
 
+#client_connection_check_interval = 0	# time between checks for client
+					# disconnection while running queries;
+					# 0 for never
 
 #------------------------------------------------------------------------------
 # LOCK MANAGEMENT