hotspot/src/share/vm/oops/oopHandle.hpp
changeset 46961 c9094b1e5f87
child 47095 9d21da6fe729
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/oops/oopHandle.hpp	Wed Aug 23 12:00:39 2017 -0400
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2017, 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_OOPS_OOPHANDLE_HPP
+#define SHARE_VM_OOPS_OOPHANDLE_HPP
+
+#include "oops/oop.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/orderAccess.hpp"
+
+// Simple class for encapsulating oop pointers stored in metadata.
+// These are different from Handle.  The Handle class stores pointers
+// to oops on the stack, and manages the allocation from a thread local
+// area in the constructor.
+// This assumes that the caller will allocate the handle in the appropriate
+// area.  The reason for the encapsulation is to help with naming and to allow
+// future uses for read barriers.
+
+class OopHandle {
+private:
+  oop* _obj;
+
+public:
+  OopHandle() : _obj(NULL) {}
+  OopHandle(oop* w) : _obj(w) {}
+
+  oop resolve() const { return (_obj == NULL) ? (oop)NULL : *_obj; }
+};
+
+#endif // SHARE_VM_OOPS_OOPHANDLE_HPP