1 /*
 2  * Copyright (c) 2001, 2019, 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_GC_PARALLEL_PSMARKSWEEPDECORATOR_HPP
26 #define SHARE_GC_PARALLEL_PSMARKSWEEPDECORATOR_HPP
27 
28 #include "gc/parallel/mutableSpace.hpp"
29 
30 //
31 // A PSMarkSweepDecorator is used to add "ParallelScavenge" style mark sweep operations
32 // to a MutableSpace.
33 //
34 
35 class ObjectStartArray;
36 
37 class PSMarkSweepDecorator: public CHeapObj<mtGC> {
38  private:
39   static PSMarkSweepDecorator* _destination_decorator;
40 
41  protected:
42   MutableSpace* _space;
43   ObjectStartArray* _start_array;
44   HeapWord* _first_dead;
45   HeapWord* _end_of_live;
46   HeapWord* _compaction_top;
47   size_t _allowed_dead_ratio;
48 
49   bool insert_deadspace(size_t& allowed_deadspace_words, HeapWord* q,
50                         size_t word_len);
51 
52  public:
53   PSMarkSweepDecorator(MutableSpace* space, ObjectStartArray* start_array,
54                        size_t allowed_dead_ratio) :
55     _space(space), _start_array(start_array),
56     _allowed_dead_ratio(allowed_dead_ratio) { }
57 
58   // During a compacting collection, we need to collapse objects into
59   // spaces in a given order. We want to fill space A, space B, and so
60   // on. The code that controls that order is in the following methods.
61   static void set_destination_decorator_tenured();
62   static void advance_destination_decorator();
63   static PSMarkSweepDecorator* destination_decorator();
64 
65   // Accessors
66   MutableSpace* space()                     { return _space; }
67   ObjectStartArray* start_array()           { return _start_array; }
68 
69   HeapWord* compaction_top()                { return _compaction_top; }
70   void set_compaction_top(HeapWord* value)  { _compaction_top = value; }
71 
72   size_t allowed_dead_ratio()               { return _allowed_dead_ratio; }
73   void set_allowed_dead_ratio(size_t value) { _allowed_dead_ratio = value; }
74 
75   // Work methods
76   void adjust_pointers();
77   void precompact();
78   void compact(bool mangle_free_space);
79 };
80 
81 #endif // SHARE_GC_PARALLEL_PSMARKSWEEPDECORATOR_HPP