Partially deduplicate interrupt handling for background processes.

Where possible, share signal handler code and main loop interrupt
checking. This saves quite a bit of code and should simplify
maintenance, too.

This commit intends not to change the way anything works, even
though that might allow more code to be unified. It does unify
a bunch of individual variables into a ShutdownRequestPending
flag that has is now used by a bunch of different process types,
though.

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

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

1 files changed, 5 insertions, 24 deletions

diff --git a/src/backend/postmaster/pgarch.c b/src/backend/postmaster/pgarch.c
index 09a9c66b4b2..7824180ac7f 100644
--- a/src/backend/postmaster/pgarch.c
+++ b/src/backend/postmaster/pgarch.c
@@ -39,6 +39,7 @@
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "postmaster/fork_process.h"
+#include "postmaster/interrupt.h"
 #include "postmaster/pgarch.h"
 #include "postmaster/postmaster.h"
 #include "storage/dsm.h"
@@ -83,7 +84,6 @@ 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_SIGTERM = false;
 static volatile sig_atomic_t wakened = false;
 static volatile sig_atomic_t ready_to_stop = false;
 
@@ -97,7 +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 ArchSigTermHandler(SIGNAL_ARGS);
 static void pgarch_waken(SIGNAL_ARGS);
 static void pgarch_waken_stop(SIGNAL_ARGS);
 static void pgarch_MainLoop(void);
@@ -227,9 +226,9 @@ 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, PostgresSigHupHandler);
+	pqsignal(SIGHUP, SignalHandlerForConfigReload);
 	pqsignal(SIGINT, SIG_IGN);
-	pqsignal(SIGTERM, ArchSigTermHandler);
+	pqsignal(SIGTERM, SignalHandlerForShutdownRequest);
 	pqsignal(SIGQUIT, pgarch_exit);
 	pqsignal(SIGALRM, SIG_IGN);
 	pqsignal(SIGPIPE, SIG_IGN);
@@ -257,24 +256,6 @@ pgarch_exit(SIGNAL_ARGS)
 	exit(1);
 }
 
-/* SIGTERM signal handler for archiver process */
-static void
-ArchSigTermHandler(SIGNAL_ARGS)
-{
-	int			save_errno = errno;
-
-	/*
-	 * The postmaster never sends us SIGTERM, so we assume that this means
-	 * that init is trying to shut down the whole system.  If we hang around
-	 * too long we'll get SIGKILL'd.  Set flag to prevent starting any more
-	 * archive commands.
-	 */
-	got_SIGTERM = true;
-	SetLatch(MyLatch);
-
-	errno = save_errno;
-}
-
 /* SIGUSR1 signal handler for archiver process */
 static void
 pgarch_waken(SIGNAL_ARGS)
@@ -346,7 +327,7 @@ pgarch_MainLoop(void)
 		 * idea.  If more than 60 seconds pass since SIGTERM, exit anyway, so
 		 * that the postmaster can start a new archiver if needed.
 		 */
-		if (got_SIGTERM)
+		if (ShutdownRequestPending)
 		{
 			time_t		curtime = time(NULL);
 
@@ -434,7 +415,7 @@ pgarch_ArchiverCopyLoop(void)
 			 * command, and the second is to avoid conflicts with another
 			 * archiver spawned by a newer postmaster.
 			 */
-			if (got_SIGTERM || !PostmasterIsAlive())
+			if (ShutdownRequestPending || !PostmasterIsAlive())
 				return;
 
 			/*