Fix sem_post race (bug 14532).

1 files changed, 91 insertions, 0 deletions

diff --git a/nptl/tst-sem14.c b/nptl/tst-sem14.c
new file mode 100644
index 0000000000..949c03fcc6
--- /dev/null
+++ b/nptl/tst-sem14.c
@@ -0,0 +1,91 @@
+/* Test for sem_post race: bug 14532.
+   Copyright (C) 2012 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 <pthread.h>
+#include <semaphore.h>
+#include <stdio.h>
+
+#define NTHREADS 10
+#define NITER 100000
+
+sem_t sem;
+int c;
+volatile int thread_fail;
+
+static void *
+tf (void *arg)
+{
+  for (int i = 0; i < NITER; i++)
+    {
+      if (sem_wait (&sem) != 0)
+	{
+	  perror ("sem_wait");
+	  thread_fail = 1;
+	}
+      ++c;
+      if (sem_post (&sem) != 0)
+	{
+	  perror ("sem_post");
+	  thread_fail = 1;
+	}
+    }
+  return NULL;
+}
+
+static int
+do_test (void)
+{
+  if (sem_init (&sem, 0, 0) != 0)
+    {
+      perror ("sem_init");
+      return 1;
+    }
+
+  pthread_t th[NTHREADS];
+  for (int i = 0; i < NTHREADS; i++)
+    {
+      if (pthread_create (&th[i], NULL, tf, NULL) != 0)
+	{
+	  puts ("pthread_create failed");
+	  return 1;
+	}
+    }
+
+  if (sem_post (&sem) != 0)
+    {
+      perror ("sem_post");
+      return 1;
+    }
+
+  for (int i = 0; i < NTHREADS; i++)
+    if (pthread_join (th[i], NULL) != 0)
+      {
+	puts ("pthread_join failed");
+	return 1;
+      }
+
+  if (c != NTHREADS * NITER)
+    {
+      printf ("c = %d, should be %d\n", c, NTHREADS * NITER);
+      return 1;
+    }
+  return thread_fail;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"