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