From: Francis Cianfrocca <garbagecat10@...>
Date: 2006-08-27T23:54:46+09:00
Subject: Re: Ruby threads and the system call

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On 8/27/06, Vincent Fourmond <vincent.fourmond@9online.fr> wrote:
>
>
>   Hello !
>
>   I've recently had quite a fair bit of trouble with Ruby threads (on a
> Linux box). I wrote three different programs (attached) that write
> numbers from within threads:
>
>   * one with a standard puts
>   * one with a system "echo ..."
>   * one with a fork do system "echo ..." end



Both fork and the system call have the effect of creating a subprocess which
then interacts with your main process through open file descriptors and
through signals. Both interact badly with threads. I suggest you consider a
non-threaded design, fork off your subprocesses, and use waitpid2 to
distinguish the various returns. If you need to capture data generated by
print statements in the subprocesses, then you can play painful games like
redirecting the standard file descriptors to other file numbers, or you can
simply make sure you only have one subprocess in flight at a time.

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