[glib/wip/kalev/recursive-mutex-locker: 7/7] tests: Update GMutexLocker tests

[Kalev Lember <klember src gnome org>]

commit d2dd6ae1f72309c55e1f872fb93071c7ead94d9a
Author: Kalev Lember <klember redhat com>
Date:   Fri Dec 14 17:30:58 2018 +0100

    tests: Update GMutexLocker tests
    
    Spawn a thread and assert that the mutex actually got locked and then
    unlocked again, same as we do in GRecMutexLocker tests.

 glib/tests/autoptr.c | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)
---
diff --git a/glib/tests/autoptr.c b/glib/tests/autoptr.c
index 076acced7..92d4bbaca 100644
--- a/glib/tests/autoptr.c
+++ b/glib/tests/autoptr.c
@@ -329,10 +329,30 @@ test_g_mutex (void)
   g_mutex_init (&val);
 }
 
+/* Thread function to check that a mutex given in @data is locked */
+static gpointer
+mutex_locked_thread (gpointer data)
+{
+  GMutex *mutex = (GMutex *) data;
+  g_assert_false (g_mutex_trylock (mutex));
+  return NULL;
+}
+
+/* Thread function to check that a mutex given in @data is unlocked */
+static gpointer
+mutex_unlocked_thread (gpointer data)
+{
+  GMutex *mutex = (GMutex *) data;
+  g_assert_true (g_mutex_trylock (mutex));
+  g_mutex_unlock (mutex);
+  return NULL;
+}
+
 static void
 test_g_mutex_locker (void)
 {
   GMutex mutex;
+  GThread *thread;
 
   g_mutex_init (&mutex);
 
@@ -340,8 +360,16 @@ test_g_mutex_locker (void)
     {
       g_autoptr(GMutexLocker) val = g_mutex_locker_new (&mutex);
       
-      g_assert (val != NULL);
+      g_assert_nonnull (val);
+
+      /* Verify that the mutex is actually locked */
+      thread = g_thread_new ("mutex locked", mutex_locked_thread, &mutex);
+      g_thread_join (thread);
     }
+
+    /* Verify that the mutex is unlocked again */
+    thread = g_thread_new ("mutex unlocked", mutex_unlocked_thread, &mutex);
+    g_thread_join (thread);
 }
 
 /* Thread function to check that a recursive mutex given in @data is locked */