1 files changed, 79 insertions, 0 deletions
diff --git a/stdlib/test-dlclose-exit-race-helper.c b/stdlib/test-dlclose-exit-race-helper.c
new file mode 100644
index 0000000000..fa765899bc
--- /dev/null
+++ b/stdlib/test-dlclose-exit-race-helper.c
@@ -0,0 +1,79 @@
+/* Helper for exit/dlclose race test (Bug 22180).
+   Copyright (C) 2017 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
+   <http://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);
+}