Add some atomic ops tests

gthread/tests/Makefile.am

@@ -18,3 +18,7 @@ TEST_PROGS += unix-multithreaded
 unix_multithreaded_SOURCES = $(top_srcdir)/glib/tests/unix.c
 unix_multithreaded_CFLAGS   = -DTEST_THREADED
 unix_multithreaded_LDADD    = $(progs_ldadd) $(top_builddir)/gthread/libgthread-2.0.la
+
+TEST_PROGS += atomic
+atomic_SOURCES = atomic.c
+atomic_LDADD = $(progs_ldadd) $(top_builddir)/gthread/libgthread-2.0.la

gthread/tests/atomic.c

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2011 Red Hat, Inc.
+ *
+ * This program 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 of the
+ * License, or (at your option) any later version.
+ *
+ * See the included COPYING file for more information.
+ */
+
+#include <glib.h>
+
+#define THREADS 10
+#define ROUNDS 10000
+
+volatile gint bucket[THREADS];
+volatile gint atomic;
+
+static gpointer
+thread_func (gpointer data)
+{
+  gint idx = GPOINTER_TO_INT (data);
+  gint i;
+  gint d;
+
+  for (i = 0; i < ROUNDS; i++)
+    {
+      d = g_random_int_range (-10, 100);
+      bucket[idx] += d;
+      g_atomic_int_add (&atomic, d);
+      g_thread_yield ();
+    }
+
+  return NULL;
+}
+
+static void
+test_atomic (void)
+{
+  gint sum;
+  gint i;
+  GThread *threads[THREADS];
+
+  atomic = 0;
+  for (i = 0; i < THREADS; i++)
+    bucket[i] = 0;
+
+  for (i = 0; i < THREADS; i++)
+    threads[i] = g_thread_create (thread_func, GINT_TO_POINTER (i), TRUE, NULL);
+
+  for (i = 0; i < THREADS; i++)
+    g_thread_join (threads[i]);
+
+  sum = 0;
+  for (i = 0; i < THREADS; i++)
+    sum += bucket[i];
+
+  g_assert_cmpint (sum, ==, atomic);
+}
+
+int
+main (int argc, char *argv[])
+{
+  g_thread_init (NULL);
+
+  g_test_init (&argc, &argv, NULL);
+
+  g_test_add_func ("/glib/atomic/add", test_atomic);
+
+  return g_test_run ();
+}