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Message-ID:	<eb7786ee-dc7a-4689-9d17-b842e581d7c7@maxrnd.com>
Date:	Tue, 17 Jun 2025 15:42:26 -0700
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Subject:	Re: Calling system() in multi-threads.
To:	cygwin AT cygwin DOT com
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From:	Mark Geisert via Cygwin <cygwin AT cygwin DOT com>
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This is a multi-part message in MIME format.
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Hi Takashi,

On 6/17/2025 5:54 AM, Takashi Yano via Cygwin wrote:
> Hi,
> 
> If system() is called in parallel in threads, system()
> fails with exit code 127.
> 
> Just compile pthread_system.c attached and run.
> 
> I believe system() is multi-thread safe so the STC
> should work.

I regret to inform that system() is not currently MT-safe.  I discovered 
this a few years ago when porting YAFU (Yet Another Factoring Utility).

I ended up supplying a wrapper that serialized the system() call itself 
but allowed multiple wrappers (and thus child processes) to be running 
at the same time.  I never got around to supplying a fix for Cygwin. 
I've attached the code.
HTH somehow,

..mark

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