Date: Thu, 15 Oct 1998 09:25:05 -0700 (PDT) From: info@highwind.com To: freebsd-gnats-submit@FreeBSD.ORG Subject: kern/8335: pthread_cond_timedwait() is broken Message-ID: <199810151625.JAA15891@hub.freebsd.org>
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>Number: 8335
>Category: kern
>Synopsis: pthread_cond_timedwait() is broken
>Confidential: no
>Severity: serious
>Priority: high
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Thu Oct 15 09:30:00 PDT 1998
>Last-Modified:
>Originator: Robert Fleischman
>Organization:
HighWind Software
>Release: 3.0
>Environment:
FreeBSD zonda.highwind.com 3.0-19980831-SNAP FreeBSD 3.0-19980831-SNAP #0: Mon Aug 31 14:03:19 GMT 1998 root@make.ican.net:/usr/src/sys/compile/GENERIC i386
>Description:
It appears that in recent 3.0 kernels, pthread_cond_timedwait() doesn't
work properly. This is true even with the latest libc_r.
I've included a test program.
>How-To-Repeat:
/* Illustration of FreeBSD pthread_cond_timedwait() bug
This program sets up a timed conditional wait. It just calls
cond_timed_wait(). This should BLOCK for 15 seconds and the program
should terminate normally.
However, because of some bugs in FreeBSD, the cond_timed_wait
returns with no error. It looks as if someone has signaled the
condition. Clearly, that is impossible and there is some kind of bug!
g++ -o condBug -D_REENTRANT -D_THREAD_SAFE -g -Wall condBug.C -pthread
*/
#include <assert.h>
#include <pthread.h>
#include <stdlib.h>
int main(int, char **)
{
pthread_mutex_t lock;
pthread_cond_t condition;
// Initialize Lock
pthread_mutexattr_t lock_attr;
assert(!::pthread_mutexattr_init(&lock_attr));
assert(!::pthread_mutex_init(&lock, &lock_attr));
assert(!::pthread_mutexattr_destroy(&lock_attr));
// Initialize Condition
pthread_condattr_t cond_attr;
assert(!::pthread_condattr_init(&cond_attr));
assert(!::pthread_cond_init(&condition, &cond_attr));
assert(!::pthread_condattr_destroy(&cond_attr));
// Grab current time
time_t currentTime = ::time(0);
// Lock the lock
assert(!::pthread_mutex_lock(&lock));
// Wait in the condition for 15 seconds
timespec timeOut;
timeOut.tv_sec = currentTime + 15;
timeOut.tv_nsec = 0;
int err = ::pthread_cond_timedwait(&condition, &lock, &timeOut);
// We better get an error (we should have TIMED OUT!)
assert(err);
// 15 seconds SHOULD have passed, so 5 seconds DEFINATELY should have!!
assert(::time(0) >= currentTime + 5);
return EXIT_SUCCESS;
}
>Fix:
>Audit-Trail:
>Unformatted:
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