From: Eli Barzilay <eli@barzilay.org>
To: linux-kernel@vger.kernel.org
Subject: Repost: Bug with select?
Date: Thu, 24 Jul 2003 01:28:10 -0400 [thread overview]
Message-ID: <16159.28266.868297.372200@mojave.cs.cornell.edu> (raw)
In-Reply-To: <16112.10166.989608.288954@mojave.cs.cornell.edu>
[This is a second post, since I didn't get any replies the first time.
It looks more like a bug now, which sounds strange for something that
common...]
When I run the following program, and block the terminal's output
(C-s), the `select' doesn't seem to have any effect, resulting in a
100% cpu usage (this is on a RH8, with 2.4.18). I wouldn't be
surprised if I'm doing something stupid, but it does seem to work fine
on Solaris.
Is there anything wrong with this, or is this some bug?
======================================================================
#include <unistd.h>
#include <fcntl.h>
int main() {
int flags, fd, len; fd_set writefds;
fd = 1;
flags = fcntl(fd, F_GETFL, 0);
fcntl(fd, F_SETFL, flags | O_NONBLOCK);
while (1) {
FD_ZERO(&writefds);
FD_SET(fd, &writefds);
len = select(fd + 1, NULL, &writefds, NULL, NULL);
if (!FD_ISSET(fd,&writefds)) exit(0);
len = write(fd, "hi\n", 3);
}
fcntl(fd, F_SETFL, flags);
}
======================================================================
--
((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay:
http://www.barzilay.org/ Maze is Life!
next prev parent reply other threads:[~2003-07-24 5:13 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-06-18 8:49 Problem with select? Eli Barzilay
2003-07-24 5:28 ` Eli Barzilay [this message]
2003-07-25 13:41 ` Repost: Bug " Marco Roeland
2003-07-26 0:20 ` Ben Greear
2003-07-26 9:05 ` Marco Roeland
2003-07-26 0:35 ` Philippe Troin
2003-07-26 14:29 ` Eli Barzilay
2003-07-26 14:25 ` Eli Barzilay
2003-07-26 15:37 ` Marco Roeland
2003-07-27 19:29 Manfred Spraul
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=16159.28266.868297.372200@mojave.cs.cornell.edu \
--to=eli@barzilay.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).