static void *
outer_thread (void *closure)
{
pthread_t *threads = xcalloc (sizeof (*threads), inner_thread_count);
while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED))
{
pthread_barrier_t barrier;
xpthread_barrier_init (&barrier, NULL, inner_thread_count + 1);
for (int i = 0; i < inner_thread_count; ++i)
{
void *(*func) (void *);
if ((i % 2) == 0)
func = malloc_first_thread;
else
func = wait_first_thread;
threads[i] = xpthread_create (NULL, func, &barrier);
}
xpthread_barrier_wait (&barrier);
for (int i = 0; i < inner_thread_count; ++i)
xpthread_join (threads[i]);
xpthread_barrier_destroy (&barrier);
}
free (threads);
return NULL;
}
static int
do_test (void)
{
/* Limit the size of the process, so that memory allocation will
fail without impacting the entire system. */
{
struct rlimit limit;
if (getrlimit (RLIMIT_AS, &limit) != 0)
{
printf ("FAIL: getrlimit (RLIMIT_AS) failed: %m\n");
return 1;
}
/* This limit, 800MB, is just a heuristic. Any value can be
picked. */
long target = 800 * 1024 * 1024;
if (limit.rlim_cur == RLIM_INFINITY || limit.rlim_cur > target)
{
limit.rlim_cur = target;
if (setrlimit (RLIMIT_AS, &limit) != 0)
{
printf ("FAIL: setrlimit (RLIMIT_AS) failed: %m\n");
return 1;
}
}
}
xpthread_attr_init (&detached);
xpthread_attr_setdetachstate (&detached, PTHREAD_CREATE_DETACHED);
/* A large thread stack seems beneficial for reproducing a race
condition in detached thread creation. The goal is to reach the
limit of the runtime thread stack cache such that the detached
thread's stack is unmapped after exit and causes a segfault when
the parent reads the thread descriptor data stored on the the
unmapped stack. */
xpthread_attr_setstacksize (&detached, 16 * 1024 * 1024);
xpthread_barrier_init (&barrier, NULL, creator_threads);
pthread_t threads[creator_threads];
for (int i = 0; i < creator_threads; ++i)
threads[i] = xpthread_create (NULL, creator_thread, NULL);
for (int i = 0; i < creator_threads; ++i)
xpthread_join (threads[i]);
xpthread_attr_destroy (&detached);
xpthread_barrier_destroy (&barrier);
return 0;
}
static int
do_test (void)
{
unsigned int i;
printf ("Starting %d threads to run %lld iterations.\n",
thread_count, iteration_count);
pthread_t *threads = xmalloc (thread_count * sizeof (pthread_t));
xpthread_barrier_init (&barrier, NULL, thread_count);
xpthread_mutex_init (&mutex, NULL);
for (i = 0; i < thread_count; i++)
threads[i] = xpthread_create (NULL, thr_func, (void *) (uintptr_t) i);
for (i = 0; i < thread_count; i++)
xpthread_join (threads[i]);
xpthread_barrier_destroy (&barrier);
free (threads);
return EXIT_SUCCESS;
}
