g_assert_cmpint (total, ==, acc1 + acc2);
}
+typedef struct
+{
+ GMutex mutex;
+ GCond cond;
+ gint limit;
+ gint count;
+} Barrier;
+
+static void
+barrier_init (Barrier *barrier,
+ gint limit)
+{
+ g_mutex_init (&barrier->mutex);
+ g_cond_init (&barrier->cond);
+ barrier->limit = limit;
+ barrier->count = limit;
+}
+
+static gint
+barrier_wait (Barrier *barrier)
+{
+ gint ret;
+
+ g_mutex_lock (&barrier->mutex);
+ barrier->count--;
+ if (barrier->count == 0)
+ {
+ ret = -1;
+ barrier->count = barrier->limit;
+ g_cond_broadcast (&barrier->cond);
+ }
+ else
+ {
+ ret = 0;
+ while (barrier->count != barrier->limit)
+ g_cond_wait (&barrier->cond, &barrier->mutex);
+ }
+ g_mutex_unlock (&barrier->mutex);
+
+ return ret;
+}
+
+static Barrier b;
+static gint check;
+
+gpointer
+cond2_func (gpointer data)
+{
+ gint value = GPOINTER_TO_INT (data);
+ gint ret;
+
+ g_atomic_int_inc (&check);
+
+ if (g_test_verbose ())
+ g_print ("thread %d starting, check %d\n", value, g_atomic_int_get (&check));
+
+ g_usleep (10000 * value);
+
+ g_atomic_int_inc (&check);
+
+ if (g_test_verbose ())
+ g_print ("thread %d reaching barrier, check %d\n", value, g_atomic_int_get (&check));
+
+ ret = barrier_wait (&b);
+
+ g_assert_cmpint (g_atomic_int_get (&check), ==, 10);
+
+ if (g_test_verbose ())
+ g_print ("thread %d leaving barrier (%d), check %d\n", value, ret, g_atomic_int_get (&check));
+
+ return NULL;
+}
+
+/* this test demonstrates how to use a condition variable
+ * to implement a barrier
+ */
+static void
+test_cond2 (void)
+{
+ gint i;
+ GThread *threads[5];
+
+ g_atomic_int_set (&check, 0);
+
+ barrier_init (&b, 5);
+ for (i = 0; i < 5; i++)
+ threads[i] = g_thread_create (cond2_func, GINT_TO_POINTER (i), TRUE, NULL);
+
+ for (i = 0; i < 5; i++)
+ g_thread_join (threads[i]);
+
+ g_assert_cmpint (g_atomic_int_get (&check), ==, 10);
+}
+
int
main (int argc, char *argv[])
{
g_test_init (&argc, &argv, NULL);
g_test_add_func ("/thread/cond1", test_cond1);
+ g_test_add_func ("/thread/cond2", test_cond2);
return g_test_run ();
}