1 /*
2 * Copyright (c) 2001, 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_GC_SHARED_COLLECTORPOLICY_HPP
26 #define SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP
27
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shared/cardTableRS.hpp"
30 #include "gc/shared/generationSpec.hpp"
31 #include "memory/allocation.hpp"
32 #include "utilities/macros.hpp"
33
34 // This class (or more correctly, subtypes of this class)
35 // are used to define global garbage collector attributes.
36 // This includes initialization of generations and any other
37 // shared resources they may need.
38 //
39 // In general, all flag adjustment and validation should be
40 // done in initialize_flags(), which is called prior to
41 // initialize_size_info().
42 //
43 // This class is not fully developed yet. As more collector(s)
44 // are added, it is expected that we will come across further
45 // behavior that requires global attention. The correct place
46 // to deal with those issues is this class.
47
48 // Forward declarations.
49 class GenCollectorPolicy;
50 class AdaptiveSizePolicy;
51 class ConcurrentMarkSweepPolicy;
52 class G1CollectorPolicy;
53 class MarkSweepPolicy;
54
55 class CollectorPolicy : public CHeapObj<mtGC> {
56 protected:
57 virtual void initialize_alignments() = 0;
58 virtual void initialize_flags();
59 virtual void initialize_size_info();
60
61 DEBUG_ONLY(virtual void assert_flags();)
62 DEBUG_ONLY(virtual void assert_size_info();)
63
64 size_t _initial_heap_byte_size;
65 size_t _max_heap_byte_size;
66 size_t _min_heap_byte_size;
67
68 size_t _space_alignment;
69 size_t _heap_alignment;
70
71 CollectorPolicy();
72
73 public:
74 void initialize_all() {
75 initialize_alignments();
76 initialize_flags();
77 initialize_size_info();
78 }
79
80 // Return maximum heap alignment that may be imposed by the policy.
81 static size_t compute_heap_alignment();
82
83 size_t space_alignment() { return _space_alignment; }
84 size_t heap_alignment() { return _heap_alignment; }
85
86 size_t initial_heap_byte_size() { return _initial_heap_byte_size; }
87 size_t max_heap_byte_size() { return _max_heap_byte_size; }
88 size_t min_heap_byte_size() { return _min_heap_byte_size; }
89 };
90
91 class GenCollectorPolicy : public CollectorPolicy {
92 friend class TestGenCollectorPolicy;
93 friend class VMStructs;
94
95 protected:
96 size_t _min_young_size;
97 size_t _initial_young_size;
98 size_t _max_young_size;
99 size_t _min_old_size;
100 size_t _initial_old_size;
101 size_t _max_old_size;
102
103 // _gen_alignment and _space_alignment will have the same value most of the
104 // time. When using large pages they can differ.
105 size_t _gen_alignment;
106
107 void initialize_flags();
108 void initialize_size_info();
109
110 DEBUG_ONLY(void assert_flags();)
111 DEBUG_ONLY(void assert_size_info();)
112
113 // Compute max heap alignment.
114 size_t compute_max_alignment();
115
116 // Scale the base_size by NewRatio according to
117 // result = base_size / (NewRatio + 1)
118 // and align by min_alignment()
119 size_t scale_by_NewRatio_aligned(size_t base_size);
120
121 // Bound the value by the given maximum minus the min_alignment.
122 size_t bound_minus_alignment(size_t desired_size, size_t maximum_size);
123
124 public:
125 GenCollectorPolicy();
126
127 // Accessors
128 size_t min_young_size() { return _min_young_size; }
129 size_t initial_young_size() { return _initial_young_size; }
130 size_t max_young_size() { return _max_young_size; }
131 size_t gen_alignment() { return _gen_alignment; }
132 size_t min_old_size() { return _min_old_size; }
133 size_t initial_old_size() { return _initial_old_size; }
134 size_t max_old_size() { return _max_old_size; }
135
136 size_t young_gen_size_lower_bound();
137
138 size_t old_gen_size_lower_bound();
139 };
140
141 class MarkSweepPolicy : public GenCollectorPolicy {
142 protected:
143 void initialize_alignments();
144
145 public:
146 MarkSweepPolicy() {}
147 };
148
149 #endif // SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP