*** pgsql/src/port/kill.c	2009/01/01 17:24:04	1.11
--- pgsql/src/port/kill.c	2009/02/15 13:58:18	1.12
***************
*** 9,15 ****
   *	signals that the backend can recognize.
   *
   * IDENTIFICATION
!  *	  $PostgreSQL: pgsql/src/port/kill.c,v 1.10 2008/01/01 19:46:00 momjian Exp $
   *
   *-------------------------------------------------------------------------
   */
--- 9,15 ----
   *	signals that the backend can recognize.
   *
   * IDENTIFICATION
!  *	  $PostgreSQL: pgsql/src/port/kill.c,v 1.11 2009/01/01 17:24:04 momjian Exp $
   *
   *-------------------------------------------------------------------------
   */
*************** pgkill(int pid, int sig)
*** 25,30 ****
--- 25,31 ----
  	BYTE		sigData = sig;
  	BYTE		sigRet = 0;
  	DWORD		bytes;
+ 	int			pipe_tries;
  
  	/* we allow signal 0 here, but it will be ignored in pg_queue_signal */
  	if (sig >= PG_SIGNAL_COUNT || sig < 0)
*************** pgkill(int pid, int sig)
*** 39,61 ****
  		return -1;
  	}
  	snprintf(pipename, sizeof(pipename), "\\\\.\\pipe\\pgsignal_%u", pid);
! 	if (!CallNamedPipe(pipename, &sigData, 1, &sigRet, 1, &bytes, 1000))
! 	{
! 		if (GetLastError() == ERROR_FILE_NOT_FOUND)
! 			errno = ESRCH;
! 		else if (GetLastError() == ERROR_ACCESS_DENIED)
! 			errno = EPERM;
! 		else
! 			errno = EINVAL;
! 		return -1;
! 	}
! 	if (bytes != 1 || sigRet != sig)
  	{
! 		errno = ESRCH;
! 		return -1;
  	}
  
! 	return 0;
  }
  
  #endif
--- 40,72 ----
  		return -1;
  	}
  	snprintf(pipename, sizeof(pipename), "\\\\.\\pipe\\pgsignal_%u", pid);
! 
! 	/*
! 	 * Writing data to the named pipe can fail for transient reasons.
! 	 * Therefore, it is useful to retry if it fails.  The maximum number of
! 	 * calls to make was empirically determined from a 90-hour notification
! 	 * stress test.
! 	 */
! 	for (pipe_tries = 0; pipe_tries < 3; pipe_tries++)
  	{
! 		if (CallNamedPipe(pipename, &sigData, 1, &sigRet, 1, &bytes, 1000))
! 		{
! 			if (bytes != 1 || sigRet != sig)
! 			{
! 				errno = ESRCH;
! 				return -1;
! 			}
! 			return 0;
! 		}
  	}
  
! 	if (GetLastError() == ERROR_FILE_NOT_FOUND)
! 		errno = ESRCH;
! 	else if (GetLastError() == ERROR_ACCESS_DENIED)
! 		errno = EPERM;
! 	else
! 		errno = EINVAL;
! 	return -1;
  }
  
  #endif