--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/utilities/jfrTryLock.hpp	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2014, 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.
+ *
+ */
+
+#ifndef SHARE_VM_JFR_UTILITIES_JFRTRYLOCK_HPP
+#define SHARE_VM_JFR_UTILITIES_JFRTRYLOCK_HPP
+
+#include "runtime/atomic.hpp"
+#include "runtime/orderAccess.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "utilities/debug.hpp"
+
+class JfrTryLock {
+ private:
+  volatile int* const _lock;
+  bool _has_lock;
+
+ public:
+  JfrTryLock(volatile int* lock) : _lock(lock), _has_lock(Atomic::cmpxchg(1, lock, 0) == 0) {}
+
+  ~JfrTryLock() {
+    if (_has_lock) {
+      OrderAccess::fence();
+      *_lock = 0;
+    }
+  }
+
+  bool has_lock() const {
+    return _has_lock;
+  }
+};
+
+class JfrMonitorTryLock : public StackObj {
+ private:
+  Monitor* _lock;
+  bool _acquired;
+
+ public:
+  JfrMonitorTryLock(Monitor* lock) : _lock(lock), _acquired(lock->try_lock()) {}
+
+  ~JfrMonitorTryLock() {
+    if (_acquired) {
+      assert(_lock->owned_by_self(), "invariant");
+      _lock->unlock();
+    }
+  }
+
+  bool acquired() const {
+    return _acquired;
+  }
+
+};
+
+#endif // SHARE_VM_JFR_UTILITIES_JFRTRYLOCK_HPP