--- /dev/null
+/* g_once_init_*() test
+ * Copyright (C) 2007 Tim Janik
+ *
+ * This work is provided "as is"; redistribution and modification
+ * in whole or in part, in any medium, physical or electronic is
+ * permitted without restriction.
+
+ * This work 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.
+
+ * In no event shall the authors or contributors be liable for any
+ * direct, indirect, incidental, special, exemplary, or consequential
+ * damages (including, but not limited to, procurement of substitute
+ * goods or services; loss of use, data, or profits; or business
+ * interruption) however caused and on any theory of liability, whether
+ * in contract, strict liability, or tort (including negligence or
+ * otherwise) arising in any way out of the use of this software, even
+ * if advised of the possibility of such damage.
+ */
+#include <glib.h>
+#include <stdlib.h>
+
+#define N_THREADS (11)
+
+static GMutex *tmutex = NULL;
+static GCond *tcond = NULL;
+static volatile int tmain_call_count = 0;
+static char dummy_value = 'x';
+
+static void
+assert_singleton_execution1 (void)
+{
+ static volatile int seen_execution = 0;
+ int old_seen_execution = g_atomic_int_exchange_and_add (&seen_execution, 1);
+ if (old_seen_execution != 0)
+ g_error ("%s: function executed more than once", G_STRFUNC);
+}
+
+static void
+assert_singleton_execution2 (void)
+{
+ static volatile int seen_execution = 0;
+ int old_seen_execution = g_atomic_int_exchange_and_add (&seen_execution, 1);
+ if (old_seen_execution != 0)
+ g_error ("%s: function executed more than once", G_STRFUNC);
+}
+
+static void
+assert_singleton_execution3 (void)
+{
+ static volatile int seen_execution = 0;
+ int old_seen_execution = g_atomic_int_exchange_and_add (&seen_execution, 1);
+ if (old_seen_execution != 0)
+ g_error ("%s: function executed more than once", G_STRFUNC);
+}
+
+static void
+initializer1 (void)
+{
+ static volatile gsize initialized = 0;
+ if (g_once_init_enter (&initialized))
+ {
+ gsize initval = 42;
+ assert_singleton_execution1();
+ g_once_init_leave (&initialized, initval);
+ }
+}
+
+static gpointer
+initializer2 (void)
+{
+ static volatile gsize initialized = 0;
+ if (g_once_init_enter (&initialized))
+ {
+ void *pointer_value = &dummy_value;
+ assert_singleton_execution2();
+ g_once_init_leave (&initialized, (gsize) pointer_value);
+ }
+ return (void*) initialized;
+}
+
+static void
+initializer3 (void)
+{
+ static volatile gsize initialized = 0;
+ if (g_once_init_enter (&initialized))
+ {
+ gsize initval = 42;
+ assert_singleton_execution3();
+ g_usleep (25 * 1000); /* waste time for multiple threads to wait */
+ g_once_init_leave (&initialized, initval);
+ }
+}
+
+static gpointer
+tmain_call_initializer3 (gpointer user_data)
+{
+ g_mutex_lock (tmutex);
+ g_cond_wait (tcond, tmutex);
+ g_mutex_unlock (tmutex);
+ //g_printf ("[");
+ initializer3();
+ //g_printf ("]\n");
+ g_atomic_int_exchange_and_add (&tmain_call_count, 1);
+ return NULL;
+}
+
+int
+main (int argc,
+ char *argv[])
+{
+ GThread *threads[11];
+ int i;
+ /* test simple initializer */
+ initializer1();
+ initializer1();
+ /* test pointer initializer */
+ void *p = initializer2();
+ g_assert (p == &dummy_value);
+ p = initializer2();
+ g_assert (p == &dummy_value);
+ /* setup threads */
+ g_thread_init (NULL);
+ tmutex = g_mutex_new ();
+ tcond = g_cond_new ();
+ /* start multiple threads for initializer3() */
+ g_mutex_lock (tmutex);
+ for (i = 0; i < N_THREADS; i++)
+ threads[i] = g_thread_create (tmain_call_initializer3, 0, FALSE, NULL);
+ g_mutex_unlock (tmutex);
+ /* concurrently call initializer3() */
+ g_cond_broadcast (tcond);
+ /* loop until all threads passed the call to initializer3() */
+ while (g_atomic_int_get (&tmain_call_count) < i)
+ {
+ if (rand() % 2)
+ g_thread_yield(); /* concurrent shuffling for single core */
+ else
+ g_usleep (1000); /* concurrent shuffling for multi core */
+ g_cond_broadcast (tcond);
+ }
+ return 0;
+}