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From: "Espen Harlinn" <espen DOT harlinn AT seamos DOT no>
To: <cygwin-developers AT cygwin DOT com>
Subject: RE: A process can't have more than 63 child processes.
Date: Fri, 9 Feb 2001 02:57:37 +0100
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Another possible solution would be to create additional threads,
and delegate the WaitForMultipleObjects, using 3 threads, one to
manage the other two, would allow 124 children to be executed.

Espen

> -----Original Message-----
> From: cygwin-developers-owner AT sources DOT redhat DOT com
> [mailto:cygwin-developers-owner AT sources DOT redhat DOT com]On Behalf Of
> Christopher Faylor
> Sent: Thursday, February 08, 2001 3:04 PM
> To: cygwin-developers AT cygwin DOT com
> Subject: Re: A process can't have more than 63 child processes.
> 
> 
> Yep.  This has been noted before.  The WaitForMultipleObjects
> restriction makes it impractical to have more than 63 children.
> 
> I guess we should set PSIZE to 64.
> 
> cgf
> 
> On Thu, Feb 08, 2001 at 05:58:47PM +0900, Kazuhiro Fujieda wrote:
> >I'm afraid the following includes only problem reports.
> >
> >A process in Cygwin seems able to have up to 1023 children 
> >because of the following code of `subproc.cc' and `pinfo.h'.
> >
> >subproc.cc (proc_subproc)
> >247:     case PROC_ADDCHILD:
> >248:       if (nchildren >= PSIZE - 1)
> >249:	system_printf ("nchildren too large %d", nchildren);
> >250:       pchildren[nchildren] = vchild;
> >pinfo.h
> >21: #define PSIZE 1024
> >
> >But a process can't have more than 63 child process in practice,
> >because WaitForMultipleObjects can't wait over 64 objects
> >according to MSDN.
> >
> >subproc.cc (wait_subproc)
> >1234:       DWORD rc = WaitForMultipleObjects (nchildren + 
> 1, events, FALSE,
> >1235: 					 proc_loop_wait);
> >
> >In addition, fork doesn't return any error when a process create
> >too many children, because proc_subproc properly handle this
> >error as quoted above. I expect fork returns -1 and set errno to
> >EAGAIN.
> 
>