glibc/nptl/tst-mutex7.c
Carlos O'Donell 5920a4a624 mutex: Fix robust mutex lock acquire (Bug 21778)
65810f0ef0 fixed a robust mutex bug but
introduced BZ 21778: if the CAS used to try to acquire a lock fails, the
expected value is not updated, which breaks other cases in the loce
acquisition loop.  The fix is to simply update the expected value with
the value returned by the CAS, which ensures that behavior is as if the
first case with the CAS never happened (if the CAS fails).

This is a regression introduced in the last release.

Tested on x86_64, i686, ppc64, ppc64le, s390x, aarch64, armv7hl.
2017-07-29 00:02:03 -04:00

190 lines
4.5 KiB
C

/* Copyright (C) 2002-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
/* This test is a template for other tests to use. Other tests define
the following macros to change the behaviour of the template test.
The test is very simple, it configures N threads given the parameters
below and then proceeds to go through mutex lock and unlock
operations in each thread as described before for the thread
function. */
#ifndef TYPE
# define TYPE PTHREAD_MUTEX_DEFAULT
#endif
#ifndef ROBUST
# define ROBUST PTHREAD_MUTEX_STALLED
#endif
#ifndef DELAY_NSEC
# define DELAY_NSEC 11000
#endif
#ifndef ROUNDS
# define ROUNDS 1000
#endif
#ifndef N
# define N 100
#endif
static pthread_mutex_t lock;
/* Each thread locks and the subsequently unlocks the lock, yielding
the smallest critical section possible. After the unlock the thread
waits DELAY_NSEC nanoseconds before doing the lock and unlock again.
Every thread does this ROUNDS times. The lock and unlock are
checked for errors. */
static void *
tf (void *arg)
{
int nr = (long int) arg;
int cnt;
struct timespec ts = { .tv_sec = 0, .tv_nsec = DELAY_NSEC };
for (cnt = 0; cnt < ROUNDS; ++cnt)
{
if (pthread_mutex_lock (&lock) != 0)
{
printf ("thread %d: failed to get the lock\n", nr);
return (void *) 1l;
}
if (pthread_mutex_unlock (&lock) != 0)
{
printf ("thread %d: failed to release the lock\n", nr);
return (void *) 1l;
}
if ((ts.tv_sec > 0) || (ts.tv_nsec > 0))
nanosleep (&ts, NULL);
}
return NULL;
}
/* Setup and run N threads, where each thread does as described
in the above thread function. The threads are given a minimal 1MiB
stack since they don't do anything between the lock and unlock. */
static int
do_test (void)
{
pthread_mutexattr_t a;
if (pthread_mutexattr_init (&a) != 0)
{
puts ("mutexattr_init failed");
exit (1);
}
if (pthread_mutexattr_settype (&a, TYPE) != 0)
{
puts ("mutexattr_settype failed");
exit (1);
}
if (pthread_mutexattr_setrobust (&a, ROBUST) != 0)
{
puts ("mutexattr_setrobust failed");
exit (1);
}
#ifdef ENABLE_PI
if (pthread_mutexattr_setprotocol (&a, PTHREAD_PRIO_INHERIT) != 0)
{
puts ("pthread_mutexattr_setprotocol failed");
return 1;
}
#endif
int e = pthread_mutex_init (&lock, &a);
if (e != 0)
{
#ifdef ENABLE_PI
if (e == ENOTSUP)
{
puts ("PI mutexes unsupported");
return 0;
}
#endif
puts ("mutex_init failed");
return 1;
}
if (pthread_mutexattr_destroy (&a) != 0)
{
puts ("mutexattr_destroy failed");
return 1;
}
pthread_attr_t at;
pthread_t th[N];
int cnt;
if (pthread_attr_init (&at) != 0)
{
puts ("attr_init failed");
return 1;
}
if (pthread_attr_setstacksize (&at, 1 * 1024 * 1024) != 0)
{
puts ("attr_setstacksize failed");
return 1;
}
if (pthread_mutex_lock (&lock) != 0)
{
puts ("locking in parent failed");
return 1;
}
for (cnt = 0; cnt < N; ++cnt)
if (pthread_create (&th[cnt], &at, tf, (void *) (long int) cnt) != 0)
{
printf ("creating thread %d failed\n", cnt);
return 1;
}
if (pthread_attr_destroy (&at) != 0)
{
puts ("attr_destroy failed");
return 1;
}
if (pthread_mutex_unlock (&lock) != 0)
{
puts ("unlocking in parent failed");
return 1;
}
for (cnt = 0; cnt < N; ++cnt)
if (pthread_join (th[cnt], NULL) != 0)
{
printf ("joining thread %d failed\n", cnt);
return 1;
}
return 0;
}
#define TIMEOUT 60
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"