lib/44756: pthread_cond_timedwait() sometimes returns error code 3 (ESRCH)

[cryintothebluesky%googlemail.com@localhost]

>Number:         44756
>Category:       lib
>Synopsis:       pthread_cond_timedwait() sometimes returns error code 3 (ESRCH)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Mar 22 21:00:01 +0000 2011
>Originator:     Sad Clouds
>Release:        5.1
>Organization:
>Environment:
NetBSD atom 5.1_STABLE NetBSD 5.1_STABLE (GENERIC) #6: Tue Mar 15 12:39:43 GMT 
2011  roman@atom:/opt/obj.amd64/sys/arch/amd64/compile/GENERIC amd64
>Description:
pthread_cond_timedwait() sometimes returns error code 3 (ESRCH), this should 
never occur. The problem is likely to be seen when creating and exiting threads 
in a loop, when those threads call pthread_cond_timedwait().
>How-To-Repeat:
The following test program demonstrates the problem. It may take a while for 
the error to occur, but sooner or later it repeatedly occurs, e.g.:

atom$ gcc -O tmp.c -lpthread
atom$ ./a.out
pthread_cond_timedwait returned = 3


#include <stdlib.h>
#include <errno.h>

pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;

void *thread_func(void *arg)
{
        struct timespec ts;
        int int_ret;
        int i = 0;

        while (1)
        {
                if (i++ >= 10000)
                        pthread_exit(NULL);

                if (clock_gettime(CLOCK_REALTIME, &ts) != 0)
                        abort();

                /*
                Set to 1 second in the past, this should make 
pthread_cond_timedwait()
                return immediately with ETIMEDOUT.
                */
                ts.tv_sec -= 1;

                if (pthread_mutex_lock(&mutex) != 0)
                        abort();
        
                int_ret = pthread_cond_timedwait(&cond, &mutex, &ts);
                if (int_ret != 0 && int_ret != ETIMEDOUT)
                {
                        /*
                        Sometimes pthread_cond_timedwait() returns 3.
                        This should never happen.
                        */
                        printf("pthread_cond_timedwait returned = %d\n", 
int_ret);
                        exit(1);
                }

                if (pthread_mutex_unlock(&mutex) != 0)
                        abort();
        }
}

int main(void)
{
        pthread_t tid[64];
        int i;

        while (1)
        {
                for (i = 0; i < 64; i++)
                {
                        if (pthread_create(&tid[i], NULL, thread_func, NULL) != 
0)
                        {
                                abort();
                        }

                }

                for (i = 0; i < 64; i++)
                {
                        if (pthread_join(tid[i], NULL) != 0)
                                abort();
                }
        }

        pthread_exit(NULL);
}
>Fix: