2000-11-03 21:27:45

by H. Peter Anvin

[permalink] [raw]
Subject: Re: Can EINTR be handled the way BSD handles it? -- a plea from a user-land

Followup to: <[email protected]>
By author: [email protected]
In newsgroup: linux.dev.kernel
> Thanks for the info.
> After looking at it, let me modify my position a bit.
> My problem is that pthread_create (glibc 2.1.3, kernel 2.2.17 i686) is
> failing because, deep inside glibc somewhere, nanosleep() is returning
> My code is not using signals. The threading library is, and there is
> obviously some subtle bug going on here. Ever wonder why when browsing
> with Netscape and you click on a link and it says "Interrupted system
> call."? This is it. I'm arguing that the default behaviour should be
> SA_RESTART, and if some programmer is so studly that they actually know
> what the hell they are doing by disabling SA_RESTART, then they can do
> it explicitly.

They do so explicitly by not specifying SA_RESTART. It's a bitmask,
and the behaviour of each bit is specified by POSIX.

> I don't mean this to sound like a rant.

It does... it sounds like a rant someone who hasn't even bothered
looking up the relevant standards and interfaced.

> It's just that I can't possibly ascertain why someone in their right
> mind would want any behaviour different than SA_RESTART.

Synchronous post-processing of signals. Too many things cannot be
safely done in a signal handler context.

<[email protected]> at work, <[email protected]> in private!
"Unix gives you enough rope to shoot yourself in the foot."