[ECOS] Question about PThreads and signals

[Alexander Aganichev]

Hello,

Just wondering if the problem I'm running in is known or I'm doing
something wrong. I modified TCP/IP stack to send SIGIO signal to the
POSIX thread with pthread_kill like this:

==
#if 1 // SIGIO/FIOSETOWN
	if (so->so_state & SS_ASYNC)
		pthread_kill(so->so_pgid, SIGIO);
#endif
==

I also modified the code to properly set so_pgid field and double
check that. From the user code I have the following:

==
	sigaddset( &signals, SIGIO );
	pthread_sigmask( SIG_BLOCK, &signals, &oldSignals );

	while ( pGlobalParams->State == EventTask_Running )
	{
		sigwait( &signals, &sig );
==

And sigwait() not wakes on the signal from TCP/IP stack. The root of
the problem seems to be in the cyg_sigqueue() code, which do the
following:

==
    if( thread != NULL )
    {
        sigaddset( &thread->sigpending, 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();
        }
    }
==

I think that thread->sigmask should not be used non-inverted here, so
that's why my thread is not waked (have not tested the reverted
condition though). Can anyone please comment if I'm right? Thanks in
advance.

-- 
WBR, Alexander

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