--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/utilities/spinYield.cpp	Mon Apr 09 01:22:37 2018 -0400
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2018, 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 "runtime/os.hpp"
+#include "utilities/ostream.hpp"
+#include "utilities/spinYield.hpp"
+#include "utilities/ticks.inline.hpp"
+
+SpinYield::SpinYield(uint spin_limit, uint yield_limit) :
+  _sleep_time(),
+  _spins(0),
+  _yields(0),
+  _spin_limit(os::is_MP() ? spin_limit : 0),
+  _yield_limit(yield_limit)
+{}
+
+void SpinYield::yield_or_sleep() {
+  if (_yields < _yield_limit) {
+    ++_yields;
+    os::naked_yield();
+  } else {
+    Ticks sleep_start = Ticks::now();
+    os::naked_short_sleep(1);
+    Ticks sleep_end = Ticks::now();
+    _sleep_time += (sleep_end - sleep_start);
+  }
+}
+
+static const char* print_separator(outputStream* s, const char* separator) {
+  s->print("%s", separator);
+  return ", ";
+}
+
+void SpinYield::report(outputStream* s) const {
+  const char* initial_separator = "";
+  const char* separator = initial_separator;
+  if (_spins > 0) {             // Report spins, if any.
+    separator = print_separator(s, separator);
+    s->print("spins = %u", _spins);
+  }
+  if (_yields > 0) {            // Report yields, if any.
+    separator = print_separator(s, separator);
+    s->print("yields = %u", _yields);
+  }
+  if (_sleep_time.value() != 0) { // Report sleep duration, if slept.
+    separator = print_separator(s, separator);
+    s->print("sleep = " JLONG_FORMAT " usecs",
+             TicksToTimeHelper::milliseconds(_sleep_time));
+  }
+  if (separator == initial_separator) {
+    s->print("no waiting");
+  }
+}