walreceiver-restart-fix.patch

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 83e99b7..6c79c36 100644
*** a/src/backend/postmaster/postmaster.c
--- b/src/backend/postmaster/postmaster.c
*************** static volatile sig_atomic_t start_autov
*** 357,362 ****
--- 357,365 ----
  /* the launcher needs to be signalled to communicate some condition */
  static volatile bool avlauncher_needs_signal = false;
  
+ /* received START_WALRECEIVER signal */
+ static volatile sig_atomic_t WalReceiverRequested = false;
+ 
  /* set when there's a worker that needs to be started up */
  static volatile bool StartWorkerNeeded = true;
  static volatile bool HaveCrashedWorker = false;
*************** static void maybe_start_bgworkers(void);
*** 426,431 ****
--- 429,435 ----
  static bool CreateOptsFile(int argc, char *argv[], char *fullprogname);
  static pid_t StartChildProcess(AuxProcType type);
  static void StartAutovacuumWorker(void);
+ static void MaybeStartWalReceiver(void);
  static void InitPostmasterDeathWatchHandle(void);
  
  /*
*************** ServerLoop(void)
*** 1810,1815 ****
--- 1814,1823 ----
  				kill(AutoVacPID, SIGUSR2);
  		}
  
+ 		/* If we need to start a WAL receiver, try to do that now */
+ 		if (WalReceiverRequested)
+ 			MaybeStartWalReceiver();
+ 
  		/* Get other worker processes running, if needed */
  		if (StartWorkerNeeded || HaveCrashedWorker)
  			maybe_start_bgworkers();
*************** reaper(SIGNAL_ARGS)
*** 2958,2964 ****
  		/*
  		 * Was it the wal receiver?  If exit status is zero (normal) or one
  		 * (FATAL exit), we assume everything is all right just like normal
! 		 * backends.
  		 */
  		if (pid == WalReceiverPID)
  		{
--- 2966,2973 ----
  		/*
  		 * Was it the wal receiver?  If exit status is zero (normal) or one
  		 * (FATAL exit), we assume everything is all right just like normal
! 		 * backends.  (If we need a new wal receiver, we'll start one at the
! 		 * next iteration of the postmaster's main loop.)
  		 */
  		if (pid == WalReceiverPID)
  		{
*************** sigusr1_handler(SIGNAL_ARGS)
*** 5066,5079 ****
  		StartAutovacuumWorker();
  	}
  
! 	if (CheckPostmasterSignal(PMSIGNAL_START_WALRECEIVER) &&
! 		WalReceiverPID == 0 &&
! 		(pmState == PM_STARTUP || pmState == PM_RECOVERY ||
! 		 pmState == PM_HOT_STANDBY || pmState == PM_WAIT_READONLY) &&
! 		Shutdown == NoShutdown)
  	{
  		/* Startup Process wants us to start the walreceiver process. */
! 		WalReceiverPID = StartWalReceiver();
  	}
  
  	if (CheckPostmasterSignal(PMSIGNAL_ADVANCE_STATE_MACHINE) &&
--- 5075,5086 ----
  		StartAutovacuumWorker();
  	}
  
! 	if (CheckPostmasterSignal(PMSIGNAL_START_WALRECEIVER))
  	{
  		/* Startup Process wants us to start the walreceiver process. */
! 		/* Start immediately if possible, else remember request for later. */
! 		WalReceiverRequested = true;
! 		MaybeStartWalReceiver();
  	}
  
  	if (CheckPostmasterSignal(PMSIGNAL_ADVANCE_STATE_MACHINE) &&
*************** StartAutovacuumWorker(void)
*** 5410,5415 ****
--- 5417,5440 ----
  }
  
  /*
+  * MaybeStartWalReceiver
+  *		Start the WAL receiver process, if requested and our state allows.
+  */
+ static void
+ MaybeStartWalReceiver(void)
+ {
+ 	if (WalReceiverPID == 0 &&
+ 		(pmState == PM_STARTUP || pmState == PM_RECOVERY ||
+ 		 pmState == PM_HOT_STANDBY || pmState == PM_WAIT_READONLY) &&
+ 		Shutdown == NoShutdown)
+ 	{
+ 		WalReceiverPID = StartWalReceiver();
+ 		WalReceiverRequested = false;
+ 	}
+ }
+ 
+ 
+ /*
   * Create the opts file
   */
  static bool