From: "Boris V. Guzhov" <borg@int.spb.ru>
To: "Jonathan Larmour" <jlarmour@redhat.com>
Cc: <ecos-discuss@sourceware.cygnus.com>
Subject: Re: [ECOS] select() and signal's
Date: Sat, 21 Apr 2001 06:02:00 -0000 [thread overview]
Message-ID: <006401c0ca63$1bd96920$7601a8c0@borg> (raw)
In-Reply-To: <3AE097E4.54468B43@redhat.com>
I tried and it works. But there are some questions.
Now pthread_kill() interrupts not only select(), but
also sem_wait().
As far as I know, the POSIX semaphores are a general and
exclusive synchronization mechanism with a signal-cathing
function. And their functions should not be interrupted by
signals.
In Linux inplementation pthread_kill() not interrupts
the sem_wait().
That's right?
--
Boris Guzhov,
St.Petersburg, Russia
> "Boris V. Guzhov" wrote:
> >
> > But it still not works.
> > Both threads have an equal priority.
> > I carefully has looked on cyg_sigqueue() code.
> > And I don't understand as cyg_sigqueue() function will wake
> > the blocked in select() thread.
> > The cyg_sigqueue() function calls only signal_sigwait.broadcast().
> > But the blocked thread sleeps on other condition variable - selwait,
> > but not on signal_sigwait.
>
> Try the attached patch and let me know how you get on. I've only done some
> simple tests. But I want you to try it with your existing code rather than
> me spending more time on it[1]. *Do* let me know the outcome.
>
> Jifl
>
> [1] Since you're not a customer :)
> --
> Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062
> Maybe this world is another planet's Hell -Aldous Huxley || Opinions==mine
----------------------------------------------------------------------------
----
> ? foo
> Index: signal.cxx
> ===================================================================
> RCS file: /home/cvs/ecc/ecc/compat/posix/current/src/signal.cxx,v
> retrieving revision 1.11
> diff -u -5 -p -r1.11 signal.cxx
> --- signal.cxx 2001/02/14 01:25:44 1.11
> +++ signal.cxx 2001/04/20 20:08:54
> @@ -61,12 +61,13 @@
> #include <signal.h> // our header
> #include <setjmp.h>
> #include <unistd.h> // _exit
>
> #include <cyg/kernel/clock.hxx>
> -
> +#include <cyg/kernel/thread.hxx>
> #include <cyg/kernel/clock.inl>
> +#include <cyg/kernel/thread.inl>
>
>
// -------------------------------------------------------------------------
> // Internal definitions
>
> // Handle entry to a signal package function.
> @@ -239,16 +240,33 @@ cyg_bool cyg_sigqueue( const struct sige
> ss->pending = si;
> }
> // else A non-queuable signal, just set it pending
>
> if( thread != NULL )
> + {
> sigaddset( &thread->sigpending, signo );
> - else sigaddset( &sig_pending, signo );
> + // just wake the thread up now if it's blocked somewhere
> + if ((thread->sigpending & ~thread->sigmask) != 0)
> + {
> + thread->thread->set_asr_pending();
> + thread->thread->release();
> + }
> + }
> + else
> + {
> + sigaddset( &sig_pending, signo );
> + // Wake up any threads in sigsuspend() and sigwait().
> + if (!signal_sigwait.get_queue()->empty())
> + {
> + signal_sigwait.broadcast();
> + }
> + else
> + {
> + cyg_posix_pthread_release_thread( &sig_pending );
> + }
> + }
>
> - // Wake up any threads in sigsuspend() and sigwait().
> - signal_sigwait.broadcast();
> -
> if( !locked ) signal_mutex.unlock();
>
> return true;
> }
>
>
next prev parent reply other threads:[~2001-04-21 6:02 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-04-20 5:42 Boris V. Guzhov
2001-04-20 6:57 ` Jonathan Larmour
2001-04-20 8:13 ` Boris V. Guzhov
2001-04-20 13:11 ` Jonathan Larmour
2001-04-21 5:52 ` Boris V. Guzhov
2001-04-21 6:02 ` Boris V. Guzhov [this message]
2001-04-23 12:32 ` Jonathan Larmour
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