1 /*

     2  * Copyright (c) 2001, 2015, 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_GC_SHARED_LIVERANGE_HPP

    26 #define SHARE_VM_GC_SHARED_LIVERANGE_HPP

    27 

    28 #include "memory/memRegion.hpp"

    29 #include "utilities/copy.hpp"

    30 

    31 // This is a shared helper class used during phase 3 and 4 to move all the objects

    32 // Dead regions in a Space are linked together to keep track of the live regions

    33 // so that the live data can be traversed quickly without having to look at each

    34 // object.

    35 

    36 class LiveRange: public MemRegion {

    37 public:

    38   LiveRange(HeapWord* bottom, HeapWord* top): MemRegion(bottom, top) {}

    39 

    40   void set_end(HeapWord* e) {

    41     assert(e >= start(), "should be a non-zero range");

    42     MemRegion::set_end(e);

    43   }

    44   void set_word_size(size_t ws) {

    45     MemRegion::set_word_size(ws);

    46   }

    47 

    48   LiveRange * next() { return (LiveRange *) end(); }

    49 

    50   void move_to(HeapWord* destination) {

    51     Copy::aligned_conjoint_words(start(), destination, word_size());

    52   }

    53 };

    54 

    55 #endif // SHARE_VM_GC_SHARED_LIVERANGE_HPP