3 files changed, 56 insertions, 9 deletions
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index ad5bcfe3390..5a609958896 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -603,6 +603,15 @@ PostmasterMain(int argc, char *argv[])
 	/*
 	 * Set up signal handlers for the postmaster process.
 	 *
+	 * In the postmaster, we want to install non-ignored handlers *without*
+	 * SA_RESTART.  This is because they'll be blocked at all times except
+	 * when ServerLoop is waiting for something to happen, and during that
+	 * window, we want signals to exit the select(2) wait so that ServerLoop
+	 * can respond if anything interesting happened.  On some platforms,
+	 * signals marked SA_RESTART would not cause the select() wait to end.
+	 * Child processes will generally want SA_RESTART, but we expect them to
+	 * set up their own handlers before unblocking signals.
+	 *
 	 * CAUTION: when changing this list, check for side-effects on the signal
 	 * handling setup of child processes.  See tcop/postgres.c,
 	 * bootstrap/bootstrap.c, postmaster/bgwriter.c, postmaster/walwriter.c,
@@ -613,16 +622,20 @@ PostmasterMain(int argc, char *argv[])
 	pqinitmask();
 	PG_SETMASK(&BlockSig);
 
-	pqsignal(SIGHUP, SIGHUP_handler);	/* reread config file and have
-										 * children do same */
-	pqsignal(SIGINT, pmdie);	/* send SIGTERM and shut down */
-	pqsignal(SIGQUIT, pmdie);	/* send SIGQUIT and die */
-	pqsignal(SIGTERM, pmdie);	/* wait for children and shut down */
+	pqsignal_no_restart(SIGHUP, SIGHUP_handler);		/* reread config file
+														 * and have children do
+														 * same */
+	pqsignal_no_restart(SIGINT, pmdie); /* send SIGTERM and shut down */
+	pqsignal_no_restart(SIGQUIT, pmdie);		/* send SIGQUIT and die */
+	pqsignal_no_restart(SIGTERM, pmdie);		/* wait for children and shut
+												 * down */
 	pqsignal(SIGALRM, SIG_IGN); /* ignored */
 	pqsignal(SIGPIPE, SIG_IGN); /* ignored */
-	pqsignal(SIGUSR1, sigusr1_handler); /* message from child process */
-	pqsignal(SIGUSR2, dummy_handler);	/* unused, reserve for children */
-	pqsignal(SIGCHLD, reaper);	/* handle child termination */
+	pqsignal_no_restart(SIGUSR1, sigusr1_handler);		/* message from child
+														 * process */
+	pqsignal_no_restart(SIGUSR2, dummy_handler);		/* unused, reserve for
+														 * children */
+	pqsignal_no_restart(SIGCHLD, reaper);		/* handle child termination */
 	pqsignal(SIGTTIN, SIG_IGN); /* ignored */
 	pqsignal(SIGTTOU, SIG_IGN); /* ignored */
 	/* ignore SIGXFSZ, so that ulimit violations work like disk full */
diff --git a/src/include/port.h b/src/include/port.h
index 455f72338cd..a61e59c8f84 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -462,6 +462,11 @@ extern int	pg_mkdir_p(char *path, int omode);
 /* port/pqsignal.c */
 typedef void (*pqsigfunc) (int signo);
 extern pqsigfunc pqsignal(int signo, pqsigfunc func);
+#ifndef WIN32
+extern pqsigfunc pqsignal_no_restart(int signo, pqsigfunc func);
+#else
+#define pqsignal_no_restart(signo, func) pqsignal(signo, func)
+#endif
 
 /* port/quotes.c */
 extern char *escape_single_quotes_ascii(const char *src);
diff --git a/src/port/pqsignal.c b/src/port/pqsignal.c
index e5a73f22748..07797f909aa 100644
--- a/src/port/pqsignal.c
+++ b/src/port/pqsignal.c
@@ -32,7 +32,7 @@
 #if !defined(WIN32) || defined(FRONTEND)
 
 /*
- * Set up a signal handler for signal "signo"
+ * Set up a signal handler, with SA_RESTART, for signal "signo"
  *
  * Returns the previous handler.
  */
@@ -58,4 +58,33 @@ pqsignal(int signo, pqsigfunc func)
 #endif
 }
 
+/*
+ * Set up a signal handler, without SA_RESTART, for signal "signo"
+ *
+ * Returns the previous handler.
+ *
+ * On Windows, this would be identical to pqsignal(), so don't bother.
+ */
+#ifndef WIN32
+
+pqsigfunc
+pqsignal_no_restart(int signo, pqsigfunc func)
+{
+	struct sigaction act,
+				oact;
+
+	act.sa_handler = func;
+	sigemptyset(&act.sa_mask);
+	act.sa_flags = 0;
+#ifdef SA_NOCLDSTOP
+	if (signo == SIGCHLD)
+		act.sa_flags |= SA_NOCLDSTOP;
+#endif
+	if (sigaction(signo, &act, &oact) < 0)
+		return SIG_ERR;
+	return oact.sa_handler;
+}
+
+#endif   /* !WIN32 */
+
 #endif   /* !defined(WIN32) || defined(FRONTEND) */