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Date: Fri, 1 Feb 2002 20:49:12 -0500
From: Christopher Faylor <cgf AT redhat DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: cygipc shmat bug
Message-ID: <20020202014912.GC6842@redhat.com>
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References: <3C5937FE DOT C87567DD AT salomon DOT at> <3C59465A DOT 65EBEF58 AT salomon DOT at> <024e01c1ab6e$2a04e280$0200a8c0 AT lifelesswks>
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On Sat, Feb 02, 2002 at 09:16:57AM +1100, Robert Collins wrote:
>From: "Michael Haubenwallner" <michael DOT haubenwallner AT salomon DOT at>
>>The problem is, that the pid-numbering of Windows is quite "confuse" (i
>>don't know any better word), meaning that a later ipctest.exe gets the
>>same pid as before, while the attach before with the same pid is not
>>removed from the list yet.
>
>So don't test by PID, test by handle.  IIRC I've already suggested
>that.  Also, IIRC (Chris, Corinna you may have encountered evidence
>about this) if you have a handle open for a process, it's PID isn't
>recycled until all the handles have been closed).

That's correct.  Cygwin relies on that behavior, in fact.

In case it isn't obvious, Cygwin uses windows pids, which can be
recycled rapidly.  Relying on any specific behavior for PID numbers is
really not a good idea, even on UNIX.

cgf

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