--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/runtime/semaphore.cpp	Mon Jan 19 11:06:08 2015 +0100
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "utilities/debug.hpp"
+#include "runtime/semaphore.hpp"
+
+/////////////// Unit tests ///////////////
+
+#ifndef PRODUCT
+
+static void test_semaphore_single_separate(uint count) {
+  Semaphore sem(0);
+
+  for (uint i = 0; i < count; i++) {
+    sem.signal();
+  }
+
+  for (uint i = 0; i < count; i++) {
+    sem.wait();
+  }
+}
+
+static void test_semaphore_single_combined(uint count) {
+  Semaphore sem(0);
+
+  for (uint i = 0; i < count; i++) {
+    sem.signal();
+    sem.wait();
+  }
+}
+
+static void test_semaphore_many(uint value, uint max, uint increments) {
+  Semaphore sem(value);
+
+  uint total = value;
+
+  for (uint i = value; i + increments <= max; i += increments) {
+    sem.signal(increments);
+
+    total += increments;
+  }
+
+  for (uint i = 0; i < total; i++) {
+    sem.wait();
+  }
+}
+
+static void test_semaphore_many() {
+  for (uint max = 0; max < 10; max++) {
+    for (uint value = 0; value < max; value++) {
+      for (uint inc = 1; inc <= max - value; inc++) {
+        test_semaphore_many(value, max, inc);
+      }
+    }
+  }
+}
+
+void test_semaphore() {
+  for (uint i = 1; i < 10; i++) {
+    test_semaphore_single_separate(i);
+  }
+
+  for (uint i = 0; i < 10; i++) {
+    test_semaphore_single_combined(i);
+  }
+
+  test_semaphore_many();
+}
+
+#endif // PRODUCT
+