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Date: Thu, 27 Sep 2012 01:50:55 -0700
From: "Gregory M. Turner" <gmt AT malth DOT us>
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CC: mgsexton1 AT gmail DOT com
Subject: Re: No support for sharing unnamed semaphores between processes through shared memory?
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On 9/25/2012 2:03 PM, Linda Walsh wrote:
> Matt Sexton wrote:
>> Hello,
>>
>> I am attempting to port to Cygwin an application that synchronizes
>> between processes using unnamed semaphores in shared memory.  Both
>> processes have mapped the shared memory region, one process
>> initialize
> ----
>      There's a cygwin process that you have to have running
> for shared memory that "hosts" or holds on to the shared
> memory.
>
> I think it is the Cygwin cygserver....(but don't kill me if I'm wrong)...
>
> Something needs to hang around and hold onto that shared memory, or windows
> will recycle it.

It is cygserver -- in my limited experience, the shm works as advertised.

See http://cygwin.com/cygwin-ug-net/using-cygserver.html for gory 
details (actually, not so gory at all).

Remember to shut it down when running setup.exe, or if you rebase (this, 
because it's a regular cygwin process -- for the same reason, if you 
manage to wedge cygwin's pseudo-kernel, you may need to bounce the 
service, in addition to killing off all your other cygwin processes, 
before cygwin will so-to-speak "reboot" and unwedge).

-gmt


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