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Re: vfork / setsid interaction
On Tue, Aug 13, 2002 at 04:52:30PM +0200, Corinna Vinschen wrote:
>On Tue, Aug 13, 2002 at 10:28:09AM -0400, Joe Buehler wrote:
>> Robert Collins wrote:
>>
>> >IIRC According to SUSv2, calling *anything* after [v]fork() other than
>> >exec() may lead to unexpected behaviour.
>> >
>> >You might like to reference the SUSv2 and see what the expected
>> >behaviour is.
>>
>> Granted, but compatibility with historical UNIX behavior makes it
>> easier to port things.
>
>Not if compatibility is a big problem. And the vfork() implementation
>isn't thought to be coincidentally compatible with some random UNIX
>but to be a fast implementation to allow the common cases covered
>by the standards. Otherwise we could stick with fork() and a vfork()
>which just calls fork().
Before we dismiss the problem, however, I'd like to understand what's
going on. vfork is basically just a wrapper around spawn. If there
are problems with a process that is invoked after a vfork then that's
definitely a problem.
If there is a problem with calling setsid in vfork and not having things
correctly restored when vfork "returns", that should be pretty easy to
fix.
cgf