RE: [HACKERS] backend freezeing on win32 fixed (I hope ;-) )

Horak Daniel <horak@mmp.plzen-city.cz>

From: Horak Daniel <horak@mmp.plzen-city.cz>
To: "'Tom Lane'" <tgl@sss.pgh.pa.us>
Cc: "'pgsql-hackers@postgreSQL.org'" <pgsql-hackers@postgreSQL.org>
Date: 1999-08-17T14:26:12Z
Lists: pgsql-hackers
> How do you know it has no negative effects?  The problem that it was
> intended to fix only showed up with large numbers of backends 
> (ie, more
> than the system limit on number of semaphores, which is depressingly
> small on many old-line Unixes).  Perhaps cygipc has no limit on number
> of semaphores, or perhaps it tries to be a faithful imitation 
> of SysV ;-)
> Have you checked?

There is a static limit on the max number of semaphores, it can cause the
same problems as on Unix.

this is part of sys/sem.h:
#define SEMMNI  128             /* ?  max # of semaphore identifiers */
#define SEMMSL  32              /* <= 512 max num of semaphores per id */
?? should be 32 sems per id (DH)
#define SEMMNS  (SEMMNI*SEMMSL) /* ? max # of semaphores in system */
#define SEMOPM  32              /* ~ 100 max num of ops per semop call */
#define SEMVMX  32767           /* semaphore maximum value */

But I have thought no negative effects on other ports.

			Dan