1 /*

     2  * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 #ifndef SHARE_VM_JFR_LEAKPROFILER_UTILITIES_UNIFIEDOOP_HPP

    26 #define SHARE_VM_JFR_LEAKPROFILER_UTILITIES_UNIFIEDOOP_HPP

    27 

    28 #include "oops/oop.inline.hpp"

    29 

    30 class UnifiedOop : public AllStatic {

    31  public:

    32   static const bool is_narrow(const oop* ref) {

    33     assert(ref != NULL, "invariant");

    34     return 1 == (((u8)ref) & 1);

    35   }

    36 

    37   static const oop* decode(const oop* ref) {

    38     assert(ref != NULL, "invariant");

    39     return is_narrow(ref) ? (const oop*)(((u8)ref) & ~1) : ref;

    40   }

    41 

    42   static const oop* encode(narrowOop* ref) {

    43     assert(ref != NULL, "invariant");

    44     return (const oop*)((u8)ref | 1);

    45   }

    46 

    47   static oop dereference(const oop* ref) {

    48     assert(ref != NULL, "invariant");

    49     return is_narrow(ref) ?

    50       (oop)RawAccess<>::oop_load((narrowOop*)decode(ref)) :

    51       (oop)RawAccess<>::oop_load(const_cast<oop*>(ref));

    52 

    53   }

    54 };

    55 

    56 #endif // SHARE_VM_JFR_LEAKPROFILER_UTILITIES_UNIFIEDOOP_HPP