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Re: [PATCH] make cygipc semaphores persistent
- From: Charles Wilson <cwilson at ece dot gatech dot edu>
- To: cygwin at cygwin dot com
- Date: Fri, 20 Jun 2003 01:08:46 -0400
- Subject: Re: [PATCH] make cygipc semaphores persistent
- References: <3EF205FA.5030504@hekimian.com>
Joe Buehler wrote:
The semaphores provided by the 1.14-1 version of cygipc are not
persistent -- once
all client processes close a semaphore, it disappears. This is
different than standard
UNIX semantics, in which semaphores persist until removed or system
reboot. The
attached patch fixes this, providing the standard UNIX semantics for
semaphore lifetime.
(Semaphores will persist until ipc-daemon is killed).
I would appreciate it if the owner(s) of cygipc review this patch and
roll it in
to the "official" distribution if it looks OK. The basic trick is that
the ipc-daemon
process needs to keep an open handle for all semaphores in a non-removed
state.
It looks as though there was code in cygipc that attempted this, but it
was removed in
version 1.04.
I have included a couple typo fixes in the patch also.
This patch looks right to me, given the intent. However, I'll have to
take your word for standard 'persistence' behavior...
I'll incorporate this patch -- but I don't want to mess with cygipc-1.15
right now. Let's save this for cygipc-2.x, which should come out Real
Soon after cygwin-1.5.0. Which itself is due RSN.
--Chuck
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