Re: [PATCHES] [HACKERS] pg_arch.c call to sleep()

[Andrew Dunstan]

Magnus Hagander wrote:
We have the following warning on Windows:
pgarch.c:349: warning: implicit declaration of function `sleep'
     

To fix it we could include the right header (which appears to be 
<stdlib.h> in the Windows/Mingw case), or we could replace 
     

the call by 
   

a call to pg_usleep().
     

<stdlib.h> is included automatically by c.h, so that surely 
won't fix it.

I have some recollection that we invented pg_usleep in part 
because we wanted to not use sleep() at all in the backend, 
but I don't recall why (and the reasoning might not apply to 
the archiver process, anyway).
   

win32 signal handling won't interrupt sleep(), just pg_usleep().
 

I take this as confirmation that calling pg_usleep is the Right Thing (tm).
Here's the patch.
cheers
andrew
Index: pgarch.c
===================================================================
RCS file: /home/cvsmirror/pgsql/src/backend/postmaster/pgarch.c,v
retrieving revision 1.9
diff -c -r1.9 pgarch.c
*** pgarch.c	29 Aug 2004 05:06:46 -0000	1.9
--- pgarch.c	8 Nov 2004 12:59:49 -0000
***************
*** 338,352 ****
  
  		/*
  		 * There shouldn't be anything for the archiver to do except to
! 		 * wait for a signal, so we could use pause(3) here... ...however,
! 		 * the archiver exists to protect our data, so she wakes up
! 		 * occasionally to allow herself to be proactive. In particular
! 		 * this avoids getting stuck if a signal arrives just before we
! 		 * enter sleep().
  		 */
  		if (!wakened)
  		{
! 			sleep(PGARCH_AUTOWAKE_INTERVAL);
  
  			curtime = time(NULL);
  			if ((unsigned int) (curtime - last_copy_time) >=
--- 338,351 ----
  
  		/*
  		 * There shouldn't be anything for the archiver to do except to
! 		 * wait for a signal, ... however, the archiver exists to 
! 		 * protect our data, so she wakes up occasionally to allow 
! 		 * herself to be proactive. In particular this avoids getting 
! 		 * stuck if a signal arrives just before we sleep.
  		 */
  		if (!wakened)
  		{
! 			pg_usleep(PGARCH_AUTOWAKE_INTERVAL * 1000000L);
  
  			curtime = time(NULL);
  			if ((unsigned int) (curtime - last_copy_time) >=
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