Groups | Search | Server Info | Login | Register
Groups > comp.lang.misc > #11341
| From | Alan Bawden <alan@csail.mit.edu> |
|---|---|
| Newsgroups | comp.lang.misc |
| Subject | Re: Interrupted system call on read after ~20 minutes inactivity? |
| Date | 2025-10-06 04:05 -0400 |
| Organization | ITS Preservation Society |
| Message-ID | <86y0po3161.fsf@williamsburg.bawden.org> (permalink) |
| References | <10bpkh1$25arg$1@dont-email.me> <867bxb4l3a.fsf@williamsburg.bawden.org> <10bpo36$262ue$1@dont-email.me> <86347z4ims.fsf@williamsburg.bawden.org> <10btld4$4rsi$1@artemis.inf.ed.ac.uk> |
richard@cogsci.ed.ac.uk (Richard Tobin) writes:
In article <86347z4ims.fsf@williamsburg.bawden.org>,
Alan Bawden <alan@csail.mit.edu> wrote:
>It's not necessarily a timeout. Maybe something else in the system
>sets up an interrupt handler for some other reason. EINTR happens.
>Be prepared.
BSD fixed this over 40 years ago, but unfortunately System V messed
everything up and Posix insisted on supporting both.
Use sigaction() with SA_RESTART instead of signal() and you shouldn't
get EINTR for read().
Oh! I hadn't realized that SA_RESTART was actually part of Posix! I
thought it was a BSD thing that you couldn't use if you wanted to be
fully portable. Since I've been programming in C on various flavors of
Unix for about 40 years, I guess that may have been the case when I
first started out, and I never noticed that things had changed.
I notice that the sigaction(2) manual page on a recent FreeBSD install
still says:
The sigaction() system call is expected to conform to IEEE Std
1003.1-1990 ("POSIX.1"). The SA_ONSTACK and SA_RESTART flags are
Berkeley extensions, ...
Which sure makes it sound like SA_RESTART might not exist elsewhere.
Perhaps it didn't in the version of Posix referred to here, and the
manual page hasn't been updated in a long time...
So thank you for showing me something I wasn't aware of!
--
Alan Bawden
Back to comp.lang.misc | Previous | Next — Previous in thread | Next in thread | Find similar
Interrupted system call on read after ~20 minutes inactivity? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-04 00:59 +0200
Re: Interrupted system call on read after ~20 minutes inactivity? scott@slp53.sl.home (Scott Lurndal) - 2025-10-03 23:31 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-04 01:57 +0200
Re: Interrupted system call on read after ~20 minutes inactivity? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-10-04 00:28 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-04 02:41 +0200
Re: Interrupted system call on read after ~20 minutes inactivity? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-10-04 01:07 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? richard@cogsci.ed.ac.uk (Richard Tobin) - 2025-10-04 01:04 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-10-04 01:23 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-10-04 01:28 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? scott@slp53.sl.home (Scott Lurndal) - 2025-10-04 02:12 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-10-04 02:35 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? richard@cogsci.ed.ac.uk (Richard Tobin) - 2025-10-04 12:52 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Kaz Kylheku <643-408-1753@kylheku.com> - 2025-10-04 18:50 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Alan Bawden <alan@csail.mit.edu> - 2025-10-03 19:33 -0400
Re: Interrupted system call on read after ~20 minutes inactivity? Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-10-03 23:54 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-04 02:00 +0200
Re: Interrupted system call on read after ~20 minutes inactivity? Alan Bawden <alan@csail.mit.edu> - 2025-10-03 20:26 -0400
Re: Interrupted system call on read after ~20 minutes inactivity? richard@cogsci.ed.ac.uk (Richard Tobin) - 2025-10-05 11:39 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Alan Bawden <alan@csail.mit.edu> - 2025-10-06 04:05 -0400
Re: Interrupted system call on read after ~20 minutes inactivity? richard@cogsci.ed.ac.uk (Richard Tobin) - 2025-10-06 10:46 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Lawrence D’Oliveiro <ldo@nz.invalid> - 2025-10-06 22:04 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? richard@cogsci.ed.ac.uk (Richard Tobin) - 2025-10-04 00:18 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-04 02:27 +0200
Re: Interrupted system call on read after ~20 minutes inactivity? scott@slp53.sl.home (Scott Lurndal) - 2025-10-04 02:13 +0000
Re: Interrupted system call on read after ~20 minutes inactivity? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2025-10-05 11:43 -0700
Re: Interrupted system call on read after ~20 minutes inactivity? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2025-10-07 16:29 +0200
csiph-web