Re: forking a process that has multiple threads

From: Kasper Dupont (kasperd_at_daimi.au.dk)
Date: 08/12/03 

Date: Tue, 12 Aug 2003 21:11:06 +0200

phil-news-nospam@ipal.net wrote:
>
> In comp.os.linux.development.system Duke Robillard <duke@io.com> wrote:
> |
> | The LinuxThreads library, which is the most common thing that
> | produces "threads" on GNU/Linux systems, uses a Linux-specific
> | system call similar to exec() called clone(). It creates neither
> | processes nor threads, by the common definitions of those words.
> | One of the regular posters on c.p.t refers to the things it creates
> | as KSEs or "Kernel Schedulable Entities," which is as good a name
> | as any...at least it's accurate.
> |
> | clone() allows the newly created KSE to share some resources
> | the the process that called clone(). Among these resources
> | are heap space, file descriptors, and signal handlers, which
> | makes them look a lot like threads. Process ID isn't one of
> | the things that can be shared, so these KSE's show up in the
> | output of ps, making them look like processes.
>
> But, can they be killed by that PID?

I think it depends on the kernel version. Some recent kernel
versions hide some of the processes by prepending a . to the
directory name in /proc. Maybe the signal semantics have
changed as well. I recall reading about the old semantics to
be broken. 

-- 
Kasper Dupont -- der bruger for meget tid paa usenet.
For sending spam use mailto:aaarep@daimi.au.dk
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