signal-startupproc-on-walreceive-1.patch

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index abdf4d8..47cd6e9 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -8682,6 +8682,16 @@ StartupProcShutdownHandler(SIGNAL_ARGS)
 		shutdown_requested = true;
 }
 
+/*
+ * SIGUSR1: do nothing, but receiving the signal will wake us up if we're
+ * sleeping (on platforms where usleep() is interrupted by sleep, on other
+ * platforms this is useless).
+ */
+static void
+DoNothingHandler(SIGNAL_ARGS)
+{
+}
+
 /* Handle SIGHUP and SIGTERM signals of startup process */
 void
 HandleStartupProcInterrupts(void)
@@ -8735,7 +8745,7 @@ StartupProcessMain(void)
 	else
 		pqsignal(SIGALRM, SIG_IGN);
 	pqsignal(SIGPIPE, SIG_IGN);
-	pqsignal(SIGUSR1, SIG_IGN);
+	pqsignal(SIGUSR1, DoNothingHandler);	/* WAL record has been streamed */
 	pqsignal(SIGUSR2, SIG_IGN);
 
 	/*
@@ -8859,8 +8869,10 @@ retry:
 						goto triggered;
 
 					/*
-					 * When streaming is active, we want to react quickly when
-					 * the next WAL record arrives, so sleep only a bit.
+					 * Sleep until the next WAL record arrives, or
+					 * walreceiver dies. On some platforms, signals don't
+					 * interrupt sleep, so poll every 100 ms to ensure we
+					 * respond promptly on such platforms.
 					 */
 					pg_usleep(100000L); /* 100ms */
 				}
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 98ab484..39d8fb9 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -205,8 +205,8 @@ bool		enable_bonjour = false;
 char	   *bonjour_name;
 
 /* PIDs of special child processes; 0 when not running */
-static pid_t StartupPID = 0,
-			BgWriterPID = 0,
+pid_t		StartupPID = 0;
+static pid_t BgWriterPID = 0,
 			WalWriterPID = 0,
 			WalReceiverPID = 0,
 			AutoVacPID = 0,
@@ -433,6 +433,7 @@ typedef struct
 	PMSignalData *PMSignalState;
 	InheritableSocket pgStatSock;
 	pid_t		PostmasterPid;
+	pid_t		StartupPid;
 	TimestampTz PgStartTime;
 	TimestampTz PgReloadTime;
 	bool		redirection_done;
@@ -4595,6 +4596,7 @@ save_backend_variables(BackendParameters *param, Port *port,
 		return false;
 
 	param->PostmasterPid = PostmasterPid;
+	param->StartupPid = StartupPid;
 	param->PgStartTime = PgStartTime;
 	param->PgReloadTime = PgReloadTime;
 
@@ -4809,6 +4811,7 @@ restore_backend_variables(BackendParameters *param, Port *port)
 	read_inheritable_socket(&pgStatSock, &param->pgStatSock);
 
 	PostmasterPid = param->PostmasterPid;
+	StartupPid = param->StartupPid;
 	PgStartTime = param->PgStartTime;
 	PgReloadTime = param->PgReloadTime;
 
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index c0e7e0b..c4b4614 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -41,6 +41,7 @@
 #include "access/xlog_internal.h"
 #include "libpq/pqsignal.h"
 #include "miscadmin.h"
+#include "postmaster/postmaster.h"
 #include "replication/walreceiver.h"
 #include "storage/ipc.h"
 #include "storage/pmsignal.h"
@@ -532,6 +533,9 @@ XLogWalRcvFlush(void)
 		walrcv->receivedUpto = LogstreamResult.Flush;
 		SpinLockRelease(&walrcv->mutex);
 
+		/* Wake up startup process to process the arrived records */
+		kill(StartupPID, SIGUSR1);
+
 		/* Report XLOG streaming progress in PS display */
 		snprintf(activitymsg, sizeof(activitymsg), "streaming %X/%X",
 				 LogstreamResult.Write.xlogid, LogstreamResult.Write.xrecoff);
diff --git a/src/include/postmaster/postmaster.h b/src/include/postmaster/postmaster.h
index 56d7d8e..fcfca78 100644
--- a/src/include/postmaster/postmaster.h
+++ b/src/include/postmaster/postmaster.h
@@ -36,6 +36,8 @@ extern HANDLE PostmasterHandle;
 
 extern const char *progname;
 
+extern pid_t StartupPID;
+
 extern int	PostmasterMain(int argc, char *argv[]);
 extern void ClosePostmasterPorts(bool am_syslogger);