1/*
2 * Copyright (c) 2003, 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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25#ifndef SHARE_GC_PARALLEL_PSVIRTUALSPACE_HPP
26#define SHARE_GC_PARALLEL_PSVIRTUALSPACE_HPP
27
28#include "memory/allocation.hpp"
29#include "memory/virtualspace.hpp"
30
31// VirtualSpace for the parallel scavenge collector.
32//
33// VirtualSpace is data structure for committing a previously reserved address
34// range in smaller chunks.
35
36class PSVirtualSpace : public CHeapObj<mtGC> {
37 friend class VMStructs;
38 protected:
39 // The space is committed/uncommitted in chunks of size _alignment. The
40 // ReservedSpace passed to initialize() must be aligned to this value.
41 const size_t _alignment;
42
43 // Reserved area
44 char* _reserved_low_addr;
45 char* _reserved_high_addr;
46
47 // Committed area
48 char* _committed_low_addr;
49 char* _committed_high_addr;
50
51 // The entire space has been committed and pinned in memory, no
52 // os::commit_memory() or os::uncommit_memory().
53 bool _special;
54
55 // Convenience wrapper.
56 inline static size_t pointer_delta(const char* left, const char* right);
57
58 public:
59 PSVirtualSpace(ReservedSpace rs, size_t alignment);
60 PSVirtualSpace(ReservedSpace rs);
61
62 ~PSVirtualSpace();
63
64 // Eventually all instances should be created with the above 1- or 2-arg
65 // constructors. Then the 1st constructor below should become protected and
66 // the 2nd ctor and initialize() removed.
67 PSVirtualSpace(size_t alignment):
68 _alignment(alignment),
69 _reserved_low_addr(NULL),
70 _reserved_high_addr(NULL),
71 _committed_low_addr(NULL),
72 _committed_high_addr(NULL),
73 _special(false) {
74 }
75 PSVirtualSpace();
76 bool initialize(ReservedSpace rs, size_t commit_size);
77
78 bool contains(void* p) const;
79
80 // Accessors (all sizes are bytes).
81 size_t alignment() const { return _alignment; }
82 char* reserved_low_addr() const { return _reserved_low_addr; }
83 char* reserved_high_addr() const { return _reserved_high_addr; }
84 char* committed_low_addr() const { return _committed_low_addr; }
85 char* committed_high_addr() const { return _committed_high_addr; }
86 bool special() const { return _special; }
87
88 inline size_t committed_size() const;
89 inline size_t reserved_size() const;
90 inline size_t uncommitted_size() const;
91
92 // Operations.
93 inline void set_reserved(char* low_addr, char* high_addr, bool special);
94 inline void set_reserved(ReservedSpace rs);
95 inline void set_committed(char* low_addr, char* high_addr);
96 virtual bool expand_by(size_t bytes);
97 virtual bool shrink_by(size_t bytes);
98 virtual size_t expand_into(PSVirtualSpace* space, size_t bytes);
99 void release();
100
101#ifndef PRODUCT
102 // Debugging
103 static bool is_aligned(size_t val, size_t align);
104 bool is_aligned(size_t val) const;
105 bool is_aligned(char* val) const;
106 void verify() const;
107 virtual bool grows_up() const { return true; }
108 bool grows_down() const { return !grows_up(); }
109
110 // Helper class to verify a space when entering/leaving a block.
111 class PSVirtualSpaceVerifier: public StackObj {
112 private:
113 const PSVirtualSpace* const _space;
114 public:
115 PSVirtualSpaceVerifier(PSVirtualSpace* space): _space(space) {
116 _space->verify();
117 }
118 ~PSVirtualSpaceVerifier() { _space->verify(); }
119 };
120#endif
121
122 virtual void print_space_boundaries_on(outputStream* st) const;
123
124 // Included for compatibility with the original VirtualSpace.
125 public:
126 // Committed area
127 char* low() const { return committed_low_addr(); }
128 char* high() const { return committed_high_addr(); }
129
130 // Reserved area
131 char* low_boundary() const { return reserved_low_addr(); }
132 char* high_boundary() const { return reserved_high_addr(); }
133};
134
135// A virtual space that grows from high addresses to low addresses.
136class PSVirtualSpaceHighToLow : public PSVirtualSpace {
137 friend class VMStructs;
138 public:
139 PSVirtualSpaceHighToLow(ReservedSpace rs, size_t alignment);
140 PSVirtualSpaceHighToLow(ReservedSpace rs);
141
142 virtual bool expand_by(size_t bytes);
143 virtual bool shrink_by(size_t bytes);
144 virtual size_t expand_into(PSVirtualSpace* space, size_t bytes);
145
146 virtual void print_space_boundaries_on(outputStream* st) const;
147
148#ifndef PRODUCT
149 // Debugging
150 virtual bool grows_up() const { return false; }
151#endif
152};
153
154//
155// PSVirtualSpace inlines.
156//
157inline size_t
158PSVirtualSpace::pointer_delta(const char* left, const char* right) {
159 return ::pointer_delta((void *)left, (void*)right, sizeof(char));
160}
161
162inline size_t PSVirtualSpace::committed_size() const {
163 return pointer_delta(committed_high_addr(), committed_low_addr());
164}
165
166inline size_t PSVirtualSpace::reserved_size() const {
167 return pointer_delta(reserved_high_addr(), reserved_low_addr());
168}
169
170inline size_t PSVirtualSpace::uncommitted_size() const {
171 return reserved_size() - committed_size();
172}
173
174inline void PSVirtualSpace::set_reserved(char* low_addr, char* high_addr, bool special) {
175 _reserved_low_addr = low_addr;
176 _reserved_high_addr = high_addr;
177 _special = special;
178}
179
180inline void PSVirtualSpace::set_reserved(ReservedSpace rs) {
181 set_reserved(rs.base(), rs.base() + rs.size(), rs.special());
182}
183
184inline void PSVirtualSpace::set_committed(char* low_addr, char* high_addr) {
185 _committed_low_addr = low_addr;
186 _committed_high_addr = high_addr;
187}
188
189#endif // SHARE_GC_PARALLEL_PSVIRTUALSPACE_HPP
190