driver close from exit can't catch signal?

Michael Bloom mb at ttidca.TTI.COM
Tue Jul 31 14:24:21 AEST 1990


In article <26789 at nuchat.UUCP> steve at nuchat.UUCP (Steve Nuchia) writes:

>Since the interupt wasn't guaranteed to come, I wanted to
>be able to catch a signal.  I found that it works when the
>user calls close directly but not when close is called from exit.

>This is in a SysV thing.  Is this normal and expected?  I couldn't
>find anything about it in the AT+T driver books.

Yes. If you run /etc/crash while your driver is blocked in a close
called from exit, you'll see that all signals have been set to
SIG_IGN.

I dealt with a problem somewhat like yours once with a test of the
form "(u.u_signal[SIGKILL -1] == SIG_IGN)", which should only be true
in your close routine if it is called from exit. I didn't really like
it, but it did the job.



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