Bug#159899: marked as done (libc6: sem_wait is not interrupted by signals, as required by SuS)
Your message dated Sat, 03 Apr 2004 01:21:20 +0900
with message-id <81wu4yuz9b.wl@omega.webmasters.gr.jp>
and subject line Bug#159899: libc6: sem_wait is not interrupted by signals, as required by SuS
has caused the attached Bug report to be marked as done.
This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.
(NB: If you are a system administrator and have no idea what I am
talking about this indicates a serious mail system misconfiguration
somewhere. Please contact me immediately.)
Debian bug tracking system administrator
(administrator, Debian Bugs database)
--------------------------------------
Received: (at submit) by bugs.debian.org; 6 Sep 2002 21:48:11 +0000
>From zack@codesourcery.com Fri Sep 06 16:48:11 2002
Return-path: <zack@codesourcery.com>
Received: from egil.codesourcery.com [66.92.14.122] (mail)
by master.debian.org with esmtp (Exim 3.12 1 (Debian))
id 17nQxX-0004c1-00; Fri, 06 Sep 2002 16:48:11 -0500
Received: from zack by egil.codesourcery.com with local (Exim 3.36 #1 (Debian))
id 17nQxV-00087f-00
for <submit@bugs.debian.org>; Fri, 06 Sep 2002 14:48:09 -0700
Subject: libc6: sem_wait is not interrupted by signals, as required by SuS
From: "Zack Weinberg" <zack@codesourcery.com>
To: "Debian Bug Tracking System" <submit@bugs.debian.org>
X-Mailer: reportbug 1.99.51
Date: Fri, 06 Sep 2002 14:48:09 -0700
Message-Id: <E17nQxV-00087f-00@egil.codesourcery.com>
Delivered-To: submit@bugs.debian.org
Package: libc6
Version: 2.2.5-14
Severity: normal
Tags: upstream
The Single Unix standard requires sem_wait() to be
interrupted by a signal delivered to the process - see
http://www.opengroup.org/onlinepubs/007908799/xsh/sem_wait.html for
details. The glibc implementation of sem_wait(), however, continues
to wait on the semaphore after the signal is delivered.
To demonstrate this, I have appended a test program. Compile
with -pthread and run it; it will block forever, and be unresponsive
to ^C (^\ will kill it). On a Solaris machine, by contrast, it exits
successfully, printing nothing, after a short delay (due to the
nanosleep() call in child_thread).
Code inspection suggests this is still a bug in the latest glibc CVS.
-- System Information:
Debian Release: testing/unstable
Architecture: i386
Kernel: Linux egil 2.4.19 #1 Thu Aug 15 11:07:52 PDT 2002 i686
Locale: LANG=en_US, LC_CTYPE=en_US
-- test program:
#include <sys/types.h>
#include <errno.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
static pid_t me;
static sem_t sema;
static volatile sig_atomic_t sigint_caught = 0;
static void *
child_thread(void *unused)
{
sigset_t all;
struct timespec ts;
/* Block all signals in this thread. */
sigfillset(&all);
sigprocmask(SIG_SETMASK, &all, 0);
/* Wait a moment to be sure the main thread is blocked on the
semaphore. */
ts.tv_sec = 1;
ts.tv_nsec = 0;
nanosleep(&ts, 0);
/* Now feed the main thread a signal. This should interrupt
execution of sem_wait(). */
kill(me, SIGINT);
return 0;
}
static void
sigint_handler(int unused)
{
sigint_caught = 1;
}
int
main(void)
{
sigset_t none;
pthread_t child;
struct sigaction sa;
int status;
int semv;
/* Initialize... */
me = getpid();
sem_init(&sema, 0, 0); /* semaphore starts out locked */
sigemptyset(&none);
sigprocmask(SIG_SETMASK, &none, 0);
sa.sa_handler = sigint_handler;
sa.sa_flags = 0;
sigemptyset(&sa.sa_mask);
sigaction(SIGINT, &sa, 0);
/* Spawn child thread. */
pthread_create(&child, 0, child_thread, 0);
/* Block on semaphore. This should be interrupted by the
child sending us a signal. */
status = sem_wait(&sema);
/* status should be -1, errno should be EINTR, sigint_caught
should be 1, and the semaphore value should still be zero. */
if(status != -1)
printf("status = %d != -1\n", status);
if(errno != EINTR)
printf("errno = %s != EINTR\n", strerror(errno));
if(sigint_caught != 1)
printf("sigint_caught = %d != 1\n", sigint_caught);
sem_getvalue (&sema, &semv);
if(semv != 0)
printf("semv = %d != 0\n", semv);
/* cleanup */
pthread_join(child, 0);
sem_destroy(&sema);
return 0;
}
---------------------------------------
Received: (at 159899-done) by bugs.debian.org; 2 Apr 2004 16:21:21 +0000
>From gotom@debian.or.jp Fri Apr 02 08:21:21 2004
Return-path: <gotom@debian.or.jp>
Received: from omega.webmasters.gr.jp (webmasters.gr.jp) [218.44.239.78]
by spohr.debian.org with esmtp (Exim 3.35 1 (Debian))
id 1B9RQ1-0006I4-00; Fri, 02 Apr 2004 08:21:21 -0800
Received: from omega.webmasters.gr.jp (localhost [127.0.0.1])
by webmasters.gr.jp (Postfix) with ESMTP
id 586A0DEB58; Sat, 3 Apr 2004 01:21:20 +0900 (JST)
Date: Sat, 03 Apr 2004 01:21:20 +0900
Message-ID: <81wu4yuz9b.wl@omega.webmasters.gr.jp>
From: GOTO Masanori <gotom@debian.or.jp>
To: Glenn Maynard <glenn@zewt.org>, 159899-done@bugs.debian.org
Subject: Re: Bug#159899: libc6: sem_wait is not interrupted by signals, as required by SuS
In-Reply-To: <20040326063733.GF13484@zewt.org>
References: <20040326063733.GF13484@zewt.org>
User-Agent: Wanderlust/2.9.9 (Unchained Melody) SEMI/1.14.3 (Ushinoya)
FLIM/1.14.3 (=?ISO-8859-4?Q?Unebigory=F2mae?=) APEL/10.3 Emacs/21.2
(i386-debian-linux-gnu) MULE/5.0 (SAKAKI)
MIME-Version: 1.0 (generated by SEMI 1.14.3 - "Ushinoya")
Content-Type: text/plain; charset=US-ASCII
Delivered-To: 159899-done@bugs.debian.org
X-Spam-Checker-Version: SpamAssassin 2.60-bugs.debian.org_2004_03_25
(1.212-2003-09-23-exp) on spohr.debian.org
X-Spam-Status: No, hits=-5.0 required=4.0 tests=BAYES_00,HAS_BUG_NUMBER
autolearn=no version=2.60-bugs.debian.org_2004_03_25
X-Spam-Level:
At Fri, 26 Mar 2004 01:37:33 -0500,
Glenn Maynard wrote:
> This problem seems to be fixed in NPTL. The test program exits
> properly. It hangs if run with "LD_ASSUME_KERNEL=2.2.0".
Glenn, thanks for your checking. Exactly this is already fixed with
the latest glibc under NPTL. To be clear, I close this bug.
Regards,
-- gotom
Reply to: