drd/tests/thread_namedrd/tests/thread_name: Ensure mutex address uniqueness (see also #331847)

From: Ivo Raisr <ivosh@ivosh.net>


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13854 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/drd/tests/thread_name.c b/drd/tests/thread_name.c
index 2236eae..f71f19f 100644
--- a/drd/tests/thread_name.c
+++ b/drd/tests/thread_name.c
@@ -11,6 +11,7 @@
 #define NUM_THREADS 10
 
 
+static pthread_barrier_t s_barrier;
 static pthread_mutex_t s_mutex;
 static pthread_cond_t  s_cond;
 static int s_counter;
@@ -27,6 +28,8 @@
 
   memset(&invalid_mutex, 0xff, sizeof(invalid_mutex));
 
+  pthread_barrier_wait(&s_barrier);
+
   pthread_mutex_lock(&s_mutex);
   while (s_counter != thread_num)
     pthread_cond_wait(&s_cond, &s_mutex);
@@ -45,6 +48,7 @@
   int i;
   pthread_t tid[NUM_THREADS];
 
+  pthread_barrier_init(&s_barrier, NULL, NUM_THREADS);
   pthread_mutex_init(&s_mutex, 0);
   pthread_cond_init(&s_cond, 0);