Date: Mon, 9 Mar 2009 23:35:58 +0000 (GMT) From: Robert Watson <rwatson@FreeBSD.org> To: Timothy Redaelli <timothy@redaelli.eu> Cc: freebsd-hackers@freebsd.org Subject: Re: lockf: Invalid argument on pipe Message-ID: <alpine.BSF.2.00.0903092335060.92752@fledge.watson.org> In-Reply-To: <ac9bf7980903091448w1c3b8405la2a0084e5a947a05@mail.gmail.com> References: <ac9bf7980903091448w1c3b8405la2a0084e5a947a05@mail.gmail.com>
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On Mon, 9 Mar 2009, Timothy Redaelli wrote: > Why can't I do a lockf on a file descriptor that does not point a real file > (such as stderr, stdout, or a character device)? > > Since it works under NetBSD, Linux, Solaris. For portability between systems > I hope I can do it under FreeBSD. > > The following code is simple, but It reproduce the problem. Under > non-FreeBSD systems, It will block before the puts. Instead under FreeBSD > the lockf calls return error and, so, the lock does not works. Could you file a PR for this, with pretty much this e-mail and sample code included? There's no real reason not for it to work other than that it is likely not implemented for devfs; that should be easy to fix it but opening a PR will help us keep track of the fact that it wants to be fixed. thanks, Robert N M Watson Computer Laboratory University of Cambridge > > Any suggest? > > <snip> > #include <stdio.h> > #include <unistd.h> > #include <stdlib.h> > #include <string.h> > > int main(int argc, char *argv[]) { > char tmp[256]; > > if (lockf(2, F_LOCK, 0) == -1) > perror("lock"); > snprintf (tmp, 256, "%s XXX", argv[0]); > if (!argv[1] || strcmp(argv[1], "XXX")) > system(tmp); > puts("You should see it only after ctrl+c"); > return EXIT_SUCCESS; > } > <end snip> > > -- > Timothy Redaelli > IT Consultant > Email: timothy@redaelli.eu > Mobile: +39 (338) 1187273 > WWW: http://www.redaelli.eu/ > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" >
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