Use PostgresSigHupHandler in more places.

There seems to be no reason for every background process to have
its own flag indicating that a config-file reload is needed.
Instead, let's just use ConfigFilePending for that purpose
everywhere.

Patch by me, reviewed by Andres Freund and Daniel Gustafsson.

Discussion: http://postgr.es/m/CA+TgmoZwDk=BguVDVa+qdA6SBKef=PKbaKDQALTC_9qoz1mJqg@mail.gmail.com

src/backend/postmaster/autovacuum.c

@@ -138,7 +138,6 @@ static bool am_autovacuum_launcher = false;
 static bool am_autovacuum_worker = false;
 
 /* Flags set by signal handlers */
-static volatile sig_atomic_t got_SIGHUP = false;
 static volatile sig_atomic_t got_SIGUSR2 = false;
 static volatile sig_atomic_t got_SIGTERM = false;
 
@@ -344,7 +343,6 @@ static void perform_work_item(AutoVacuumWorkItem *workitem);
 static void autovac_report_activity(autovac_table *tab);
 static void autovac_report_workitem(AutoVacuumWorkItem *workitem,
 									const char *nspname, const char *relname);
-static void av_sighup_handler(SIGNAL_ARGS);
 static void avl_sigusr2_handler(SIGNAL_ARGS);
 static void avl_sigterm_handler(SIGNAL_ARGS);
 static void autovac_refresh_stats(void);
@@ -452,7 +450,7 @@ AutoVacLauncherMain(int argc, char *argv[])
 	 * backend, so we use the same signal handling.  See equivalent code in
 	 * tcop/postgres.c.
 	 */
-	pqsignal(SIGHUP, av_sighup_handler);
+	pqsignal(SIGHUP, PostgresSigHupHandler);
 	pqsignal(SIGINT, StatementCancelHandler);
 	pqsignal(SIGTERM, avl_sigterm_handler);
 
@@ -805,9 +803,9 @@ HandleAutoVacLauncherInterrupts(void)
 	if (got_SIGTERM)
 		AutoVacLauncherShutdown();
 
-	if (got_SIGHUP)
+	if (ConfigReloadPending)
 	{
-		got_SIGHUP = false;
+		ConfigReloadPending = false;
 		ProcessConfigFile(PGC_SIGHUP);
 
 		/* shutdown requested in config file? */
@@ -1405,18 +1403,6 @@ AutoVacWorkerFailed(void)
 	AutoVacuumShmem->av_signal[AutoVacForkFailed] = true;
 }
 
-/* SIGHUP: set flag to re-read config file at next convenient time */
-static void
-av_sighup_handler(SIGNAL_ARGS)
-{
-	int			save_errno = errno;
-
-	got_SIGHUP = true;
-	SetLatch(MyLatch);
-
-	errno = save_errno;
-}
-
 /* SIGUSR2: a worker is up and running, or just finished, or failed to fork */
 static void
 avl_sigusr2_handler(SIGNAL_ARGS)
@@ -1539,7 +1525,7 @@ AutoVacWorkerMain(int argc, char *argv[])
 	 * backend, so we use the same signal handling.  See equivalent code in
 	 * tcop/postgres.c.
 	 */
-	pqsignal(SIGHUP, av_sighup_handler);
+	pqsignal(SIGHUP, PostgresSigHupHandler);
 
 	/*
 	 * SIGINT is used to signal canceling the current table's vacuum; SIGTERM
@@ -2332,9 +2318,9 @@ do_autovacuum(void)
 		/*
 		 * Check for config changes before processing each collected table.
 		 */
-		if (got_SIGHUP)
+		if (ConfigReloadPending)
 		{
-			got_SIGHUP = false;
+			ConfigReloadPending = false;
 			ProcessConfigFile(PGC_SIGHUP);
 
 			/*
@@ -2580,9 +2566,9 @@ deleted:
 		 * Check for config changes before acquiring lock for further jobs.
 		 */
 		CHECK_FOR_INTERRUPTS();
-		if (got_SIGHUP)
+		if (ConfigReloadPending)
 		{
-			got_SIGHUP = false;
+			ConfigReloadPending = false;
 			ProcessConfigFile(PGC_SIGHUP);
 		}
 

src/backend/postmaster/bgwriter.c

@@ -89,7 +89,6 @@ static XLogRecPtr last_snapshot_lsn = InvalidXLogRecPtr;
 /*
  * Flags set by interrupt handlers for later service in the main loop.
  */
-static volatile sig_atomic_t got_SIGHUP = false;
 static volatile sig_atomic_t shutdown_requested = false;
 
 static void HandleBackgroundWriterInterrupts(void);
@@ -97,7 +96,6 @@ static void HandleBackgroundWriterInterrupts(void);
 /* Signal handlers */
 
 static void bg_quickdie(SIGNAL_ARGS);
-static void BgSigHupHandler(SIGNAL_ARGS);
 static void ReqShutdownHandler(SIGNAL_ARGS);
 
 
@@ -118,7 +116,7 @@ BackgroundWriterMain(void)
 	/*
 	 * Properly accept or ignore signals that might be sent to us.
 	 */
-	pqsignal(SIGHUP, BgSigHupHandler);	/* set flag to read config file */
+	pqsignal(SIGHUP, PostgresSigHupHandler);	/* set flag to read config file */
 	pqsignal(SIGINT, SIG_IGN);
 	pqsignal(SIGTERM, ReqShutdownHandler);	/* shutdown */
 	pqsignal(SIGQUIT, bg_quickdie); /* hard crash time */
@@ -363,9 +361,9 @@ BackgroundWriterMain(void)
 static void
 HandleBackgroundWriterInterrupts(void)
 {
-	if (got_SIGHUP)
+	if (ConfigReloadPending)
 	{
-		got_SIGHUP = false;
+		ConfigReloadPending = false;
 		ProcessConfigFile(PGC_SIGHUP);
 	}
 
@@ -413,18 +411,6 @@ bg_quickdie(SIGNAL_ARGS)
 	_exit(2);
 }
 
-/* SIGHUP: set flag to re-read config file at next convenient time */
-static void
-BgSigHupHandler(SIGNAL_ARGS)
-{
-	int			save_errno = errno;
-
-	got_SIGHUP = true;
-	SetLatch(MyLatch);
-
-	errno = save_errno;
-}
-
 /* SIGTERM: set flag to shutdown and exit */
 static void
 ReqShutdownHandler(SIGNAL_ARGS)

src/backend/postmaster/checkpointer.c

@@ -151,7 +151,6 @@ double		CheckPointCompletionTarget = 0.5;
 /*
  * Flags set by interrupt handlers for later service in the main loop.
  */
-static volatile sig_atomic_t got_SIGHUP = false;
 static volatile sig_atomic_t shutdown_requested = false;
 
 /*
@@ -179,7 +178,6 @@ static void UpdateSharedMemoryConfig(void);
 /* Signal handlers */
 
 static void chkpt_quickdie(SIGNAL_ARGS);
-static void ChkptSigHupHandler(SIGNAL_ARGS);
 static void ReqCheckpointHandler(SIGNAL_ARGS);
 static void ReqShutdownHandler(SIGNAL_ARGS);
 
@@ -206,7 +204,7 @@ CheckpointerMain(void)
 	 * want to wait for the backends to exit, whereupon the postmaster will
 	 * tell us it's okay to shut down (via SIGUSR2).
 	 */
-	pqsignal(SIGHUP, ChkptSigHupHandler);	/* set flag to read config file */
+	pqsignal(SIGHUP, PostgresSigHupHandler);	/* set flag to read config file */
 	pqsignal(SIGINT, ReqCheckpointHandler); /* request checkpoint */
 	pqsignal(SIGTERM, SIG_IGN); /* ignore SIGTERM */
 	pqsignal(SIGQUIT, chkpt_quickdie);	/* hard crash time */
@@ -535,9 +533,9 @@ CheckpointerMain(void)
 static void
 HandleCheckpointerInterrupts(void)
 {
-	if (got_SIGHUP)
+	if (ConfigReloadPending)
 	{
-		got_SIGHUP = false;
+		ConfigReloadPending = false;
 		ProcessConfigFile(PGC_SIGHUP);
 
 		/*
@@ -685,9 +683,9 @@ CheckpointWriteDelay(int flags, double progress)
 		!ImmediateCheckpointRequested() &&
 		IsCheckpointOnSchedule(progress))
 	{
-		if (got_SIGHUP)
+		if (ConfigReloadPending)
 		{
-			got_SIGHUP = false;
+			ConfigReloadPending = false;
 			ProcessConfigFile(PGC_SIGHUP);
 			/* update shmem copies of config variables */
 			UpdateSharedMemoryConfig();
@@ -835,18 +833,6 @@ chkpt_quickdie(SIGNAL_ARGS)
 	_exit(2);
 }
 
-/* SIGHUP: set flag to re-read config file at next convenient time */
-static void
-ChkptSigHupHandler(SIGNAL_ARGS)
-{
-	int			save_errno = errno;
-
-	got_SIGHUP = true;
-	SetLatch(MyLatch);
-
-	errno = save_errno;
-}
-
 /* SIGINT: set flag to run a normal checkpoint right away */
 static void
 ReqCheckpointHandler(SIGNAL_ARGS)

src/backend/postmaster/pgarch.c

@@ -83,7 +83,6 @@ static time_t last_sigterm_time = 0;
 /*
  * Flags set by interrupt handlers for later service in the main loop.
  */
-static volatile sig_atomic_t got_SIGHUP = false;
 static volatile sig_atomic_t got_SIGTERM = false;
 static volatile sig_atomic_t wakened = false;
 static volatile sig_atomic_t ready_to_stop = false;
@@ -98,7 +97,6 @@ static pid_t pgarch_forkexec(void);
 
 NON_EXEC_STATIC void PgArchiverMain(int argc, char *argv[]) pg_attribute_noreturn();
 static void pgarch_exit(SIGNAL_ARGS);
-static void ArchSigHupHandler(SIGNAL_ARGS);
 static void ArchSigTermHandler(SIGNAL_ARGS);
 static void pgarch_waken(SIGNAL_ARGS);
 static void pgarch_waken_stop(SIGNAL_ARGS);
@@ -229,7 +227,7 @@ PgArchiverMain(int argc, char *argv[])
 	 * Ignore all signals usually bound to some action in the postmaster,
 	 * except for SIGHUP, SIGTERM, SIGUSR1, SIGUSR2, and SIGQUIT.
 	 */
-	pqsignal(SIGHUP, ArchSigHupHandler);
+	pqsignal(SIGHUP, PostgresSigHupHandler);
 	pqsignal(SIGINT, SIG_IGN);
 	pqsignal(SIGTERM, ArchSigTermHandler);
 	pqsignal(SIGQUIT, pgarch_exit);
@@ -259,19 +257,6 @@ pgarch_exit(SIGNAL_ARGS)
 	exit(1);
 }
 
-/* SIGHUP signal handler for archiver process */
-static void
-ArchSigHupHandler(SIGNAL_ARGS)
-{
-	int			save_errno = errno;
-
-	/* set flag to re-read config file at next convenient time */
-	got_SIGHUP = true;
-	SetLatch(MyLatch);
-
-	errno = save_errno;
-}
-
 /* SIGTERM signal handler for archiver process */
 static void
 ArchSigTermHandler(SIGNAL_ARGS)
@@ -348,9 +333,9 @@ pgarch_MainLoop(void)
 		time_to_stop = ready_to_stop;
 
 		/* Check for config update */
-		if (got_SIGHUP)
+		if (ConfigReloadPending)
 		{
-			got_SIGHUP = false;
+			ConfigReloadPending = false;
 			ProcessConfigFile(PGC_SIGHUP);
 		}
 
@@ -457,9 +442,9 @@ pgarch_ArchiverCopyLoop(void)
 			 * setting for archive_command as soon as possible, even if there
 			 * is a backlog of files to be archived.
 			 */
-			if (got_SIGHUP)
+			if (ConfigReloadPending)
 			{
-				got_SIGHUP = false;
+				ConfigReloadPending = false;
 				ProcessConfigFile(PGC_SIGHUP);
 			}
 

src/backend/postmaster/pgstat.c

@@ -264,7 +264,6 @@ static List *pending_write_requests = NIL;
 
 /* Signal handler flags */
 static volatile bool need_exit = false;
-static volatile bool got_SIGHUP = false;
 
 /*
  * Total time charged to functions so far in the current backend.
@@ -285,7 +284,6 @@ static pid_t pgstat_forkexec(void);
 NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]) pg_attribute_noreturn();
 static void pgstat_exit(SIGNAL_ARGS);
 static void pgstat_beshutdown_hook(int code, Datum arg);
-static void pgstat_sighup_handler(SIGNAL_ARGS);
 
 static PgStat_StatDBEntry *pgstat_get_db_entry(Oid databaseid, bool create);
 static PgStat_StatTabEntry *pgstat_get_tab_entry(PgStat_StatDBEntry *dbentry,
@@ -4434,7 +4432,7 @@ PgstatCollectorMain(int argc, char *argv[])
 	 * except SIGHUP and SIGQUIT.  Note we don't need a SIGUSR1 handler to
 	 * support latch operations, because we only use a local latch.
 	 */
-	pqsignal(SIGHUP, pgstat_sighup_handler);
+	pqsignal(SIGHUP, PostgresSigHupHandler);
 	pqsignal(SIGINT, SIG_IGN);
 	pqsignal(SIGTERM, SIG_IGN);
 	pqsignal(SIGQUIT, pgstat_exit);
@@ -4466,10 +4464,10 @@ PgstatCollectorMain(int argc, char *argv[])
 	 * message.  (This effectively means that if backends are sending us stuff
 	 * like mad, we won't notice postmaster death until things slack off a
 	 * bit; which seems fine.)	To do that, we have an inner loop that
-	 * iterates as long as recv() succeeds.  We do recognize got_SIGHUP inside
-	 * the inner loop, which means that such interrupts will get serviced but
-	 * the latch won't get cleared until next time there is a break in the
-	 * action.
+	 * iterates as long as recv() succeeds.  We do check ConfigReloadPending
+	 * inside the inner loop, which means that such interrupts will get
+	 * serviced but the latch won't get cleared until next time there is a
+	 * break in the action.
 	 */
 	for (;;)
 	{
@@ -4491,9 +4489,9 @@ PgstatCollectorMain(int argc, char *argv[])
 			/*
 			 * Reload configuration if we got SIGHUP from the postmaster.
 			 */
-			if (got_SIGHUP)
+			if (ConfigReloadPending)
 			{
-				got_SIGHUP = false;
+				ConfigReloadPending = false;
 				ProcessConfigFile(PGC_SIGHUP);
 			}
 
@@ -4691,18 +4689,6 @@ pgstat_exit(SIGNAL_ARGS)
 	errno = save_errno;
 }
 
-/* SIGHUP handler for collector process */
-static void
-pgstat_sighup_handler(SIGNAL_ARGS)
-{
-	int			save_errno = errno;
-
-	got_SIGHUP = true;
-	SetLatch(MyLatch);
-
-	errno = save_errno;
-}
-
 /*
  * Subroutine to clear stats in a database entry
  *

src/backend/postmaster/walwriter.c

@@ -80,14 +80,12 @@ int			WalWriterFlushAfter = 128;
 /*
  * Flags set by interrupt handlers for later service in the main loop.
  */
-static volatile sig_atomic_t got_SIGHUP = false;
 static volatile sig_atomic_t shutdown_requested = false;
 
 static void HandleWalWriterInterrupts(void);
 
 /* Signal handlers */
 static void wal_quickdie(SIGNAL_ARGS);
-static void WalSigHupHandler(SIGNAL_ARGS);
 static void WalShutdownHandler(SIGNAL_ARGS);
 
 /*
@@ -110,7 +108,7 @@ WalWriterMain(void)
 	 * We have no particular use for SIGINT at the moment, but seems
 	 * reasonable to treat like SIGTERM.
 	 */
-	pqsignal(SIGHUP, WalSigHupHandler); /* set flag to read config file */
+	pqsignal(SIGHUP, PostgresSigHupHandler); /* set flag to read config file */
 	pqsignal(SIGINT, WalShutdownHandler);	/* request shutdown */
 	pqsignal(SIGTERM, WalShutdownHandler);	/* request shutdown */
 	pqsignal(SIGQUIT, wal_quickdie);	/* hard crash time */
@@ -278,9 +276,9 @@ WalWriterMain(void)
 static void
 HandleWalWriterInterrupts(void)
 {
-	if (got_SIGHUP)
+	if (ConfigReloadPending)
 	{
-		got_SIGHUP = false;
+		ConfigReloadPending = false;
 		ProcessConfigFile(PGC_SIGHUP);
 	}
 	if (shutdown_requested)
@@ -322,18 +320,6 @@ wal_quickdie(SIGNAL_ARGS)
 	_exit(2);
 }
 
-/* SIGHUP: set flag to re-read config file at next convenient time */
-static void
-WalSigHupHandler(SIGNAL_ARGS)
-{
-	int			save_errno = errno;
-
-	got_SIGHUP = true;
-	SetLatch(MyLatch);
-
-	errno = save_errno;
-}
-
 /* SIGTERM: set flag to exit normally */
 static void
 WalShutdownHandler(SIGNAL_ARGS)

src/backend/replication/logical/launcher.c

@@ -92,9 +92,6 @@ static void logicalrep_worker_onexit(int code, Datum arg);
 static void logicalrep_worker_detach(void);
 static void logicalrep_worker_cleanup(LogicalRepWorker *worker);
 
-/* Flags set by signal handlers */
-static volatile sig_atomic_t got_SIGHUP = false;
-
 static bool on_commit_launcher_wakeup = false;
 
 Datum		pg_stat_get_subscription(PG_FUNCTION_ARGS);
@@ -714,20 +711,6 @@ logicalrep_worker_onexit(int code, Datum arg)
 	ApplyLauncherWakeup();
 }
 
-/* SIGHUP: set flag to reload configuration at next convenient time */
-static void
-logicalrep_launcher_sighup(SIGNAL_ARGS)
-{
-	int			save_errno = errno;
-
-	got_SIGHUP = true;
-
-	/* Waken anything waiting on the process latch */
-	SetLatch(MyLatch);
-
-	errno = save_errno;
-}
-
 /*
  * Count the number of registered (not necessarily running) sync workers
  * for a subscription.
@@ -972,7 +955,7 @@ ApplyLauncherMain(Datum main_arg)
 	LogicalRepCtx->launcher_pid = MyProcPid;
 
 	/* Establish signal handlers. */
-	pqsignal(SIGHUP, logicalrep_launcher_sighup);
+	pqsignal(SIGTERM, PostgresSigHupHandler);
 	pqsignal(SIGTERM, die);
 	BackgroundWorkerUnblockSignals();
 
@@ -1061,9 +1044,9 @@ ApplyLauncherMain(Datum main_arg)
 			CHECK_FOR_INTERRUPTS();
 		}
 
-		if (got_SIGHUP)
+		if (ConfigReloadPending)
 		{
-			got_SIGHUP = false;
+			ConfigReloadPending = false;
 			ProcessConfigFile(PGC_SIGHUP);
 		}
 	}

src/backend/replication/logical/worker.c

@@ -111,9 +111,6 @@ static void store_flush_position(XLogRecPtr remote_lsn);
 
 static void maybe_reread_subscription(void);
 
-/* Flags set by signal handlers */
-static volatile sig_atomic_t got_SIGHUP = false;
-
 /*
  * Should this worker apply changes for given relation.
  *
@@ -1270,9 +1267,9 @@ LogicalRepApplyLoop(XLogRecPtr last_received)
 			CHECK_FOR_INTERRUPTS();
 		}
 
-		if (got_SIGHUP)
+		if (ConfigReloadPending)
 		{
-			got_SIGHUP = false;
+			ConfigReloadPending = false;
 			ProcessConfigFile(PGC_SIGHUP);
 		}
 
@@ -1563,20 +1560,6 @@ subscription_change_cb(Datum arg, int cacheid, uint32 hashvalue)
 	MySubscriptionValid = false;
 }
 
-/* SIGHUP: set flag to reload configuration at next convenient time */
-static void
-logicalrep_worker_sighup(SIGNAL_ARGS)
-{
-	int			save_errno = errno;
-
-	got_SIGHUP = true;
-
-	/* Waken anything waiting on the process latch */
-	SetLatch(MyLatch);
-
-	errno = save_errno;
-}
-
 /* Logical Replication Apply worker entry point */
 void
 ApplyWorkerMain(Datum main_arg)
@@ -1592,7 +1575,7 @@ ApplyWorkerMain(Datum main_arg)
 	logicalrep_worker_attach(worker_slot);
 
 	/* Setup signal handling */
-	pqsignal(SIGHUP, logicalrep_worker_sighup);
+	pqsignal(SIGHUP, PostgresSigHupHandler);
 	pqsignal(SIGTERM, die);
 	BackgroundWorkerUnblockSignals();