1 files changed, 109 insertions, 0 deletions
diff --git a/nptl/tst-mutex10.c b/nptl/tst-mutex10.c
new file mode 100644
index 0000000000..e1113ca60a
--- /dev/null
+++ b/nptl/tst-mutex10.c
@@ -0,0 +1,109 @@
+/* Testing race while enabling lock elision.
+   Copyright (C) 2018 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 <stdlib.h>
+#include <stdint.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <support/support.h>
+#include <support/xthread.h>
+
+static pthread_barrier_t barrier;
+static pthread_mutex_t mutex;
+static long long int iteration_count = 1000000;
+static unsigned int thread_count = 3;
+
+static void *
+thr_func (void *arg)
+{
+  long long int i;
+  for (i = 0; i < iteration_count; i++)
+    {
+      if ((uintptr_t) arg == 0)
+	{
+	  xpthread_mutex_destroy (&mutex);
+	  xpthread_mutex_init (&mutex, NULL);
+	}
+
+      xpthread_barrier_wait (&barrier);
+
+      /* Test if enabling lock elision works if it is enabled concurrently.
+	 There was a race in FORCE_ELISION macro which leads to either
+	 pthread_mutex_destroy returning EBUSY as the owner was recorded
+	 by pthread_mutex_lock - in "normal mutex" code path - but was not
+	 resetted in pthread_mutex_unlock - in "elision" code path.
+	 Or it leads to the assertion in nptl/pthread_mutex_lock.c:
+	 assert (mutex->__data.__owner == 0);
+	 Please ensure that the test is run with lock elision:
+	 export GLIBC_TUNABLES=glibc.elision.enable=1  */
+      xpthread_mutex_lock (&mutex);
+      xpthread_mutex_unlock (&mutex);
+
+      xpthread_barrier_wait (&barrier);
+    }
+  return NULL;
+}
+
+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;
+}
+
+#define OPT_ITERATIONS	10000
+#define OPT_THREADS	10001
+#define CMDLINE_OPTIONS						\
+  { "iterations", required_argument, NULL, OPT_ITERATIONS },	\
+  { "threads", required_argument, NULL, OPT_THREADS },
+static void
+cmdline_process (int c)
+{
+  long long int arg = strtoll (optarg, NULL, 0);
+  switch (c)
+    {
+    case OPT_ITERATIONS:
+      if (arg > 0)
+	iteration_count = arg;
+      break;
+    case OPT_THREADS:
+      if (arg > 0 && arg < 100)
+	thread_count = arg;
+      break;
+    }
+}
+#define CMDLINE_PROCESS cmdline_process
+#define TIMEOUT 50
+#include <support/test-driver.c>