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/* Helper for exit/dlclose race test (Bug 22180).
Copyright (C) 2017-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <semaphore.h>
#include <unistd.h>
#include <support/check.h>
#include <support/xthread.h>
/* Semaphore defined in executable to ensure we have a happens-before
between the first function starting and exit being called. */
extern sem_t order1;
/* Semaphore defined in executable to ensure we have a happens-before
between the second function starting and the first function returning. */
extern sem_t order2;
/* glibc function for registering DSO-specific exit functions. */
extern int __cxa_atexit (void (*func) (void *), void *arg, void *dso_handle);
/* Hidden compiler handle to this shared object. */
extern void *__dso_handle __attribute__ ((__weak__));
static void
first (void *start)
{
/* Let the exiting thread run. */
sem_post (&order1);
/* Wait for exiting thread to finish. */
sem_wait (&order2);
printf ("first\n");
}
static void
second (void *start)
{
/* We may be called from different threads.
This lock protects called. */
static pthread_mutex_t mtx = PTHREAD_MUTEX_INITIALIZER;
static bool called = false;
xpthread_mutex_lock (&mtx);
if (called)
FAIL_EXIT1 ("second called twice!");
called = true;
xpthread_mutex_unlock (&mtx);
printf ("second\n");
}
__attribute__ ((constructor)) static void
constructor (void)
{
sem_init (&order1, 0, 0);
sem_init (&order2, 0, 0);
__cxa_atexit (second, NULL, __dso_handle);
__cxa_atexit (first, NULL, __dso_handle);
}
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