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Postings from August 2002
Michael Schroeder <Michael.Schroeder@informatik.uni-erlangen.de> writes:
>Hi Porters,
>
>a somewhat surprising change in perl-5.8 is that signal handlers
>aren't installed with SA_RESTART any longer (contradicting
>perlvar.pod).
This is necessary for the synchronous signals stuff to work.
If the syscall is restarted the defered signal handler never gets
called.
>This breaks some of our programs, which e.g. use:
>
> while ($client = $server->accept()) {
> [...]
> }
>
>accept() is no longer restarted so the loop will fail if a signal
>occures.
>
>Another interesting point is that if one writes
>
> while ($client = $server->accept() || $!{EINTR}) {
> next if $!{EINTR};
> [...]
> }
>
>the signal handler mustn't do something that change $!, because
>then $! will not be EINTR anymore. This is a very unintuitive
>behaviour.
>
>So, what can be done? It would be nice if the syscalls that
>where automatically restarted in old perl versions would be
>handled like the ones in perlio.
The correct fix in PerlIO world is probably to have pp_accept()
test for EINTR, dispatch signals and re-start.
>
>What do you think?
Can you create a testcase?
>
>Cheers,
> Michael.
--
Nick Ing-Simmons
http://www.ni-s.u-net.com/
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