1 /*
2 * Copyright (c) 1997, 2013, 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.
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23 */
24
25 #ifndef SHARE_VM_RUNTIME_VIRTUALSPACE_HPP
26 #define SHARE_VM_RUNTIME_VIRTUALSPACE_HPP
27
28 #include "memory/allocation.hpp"
29
30 // ReservedSpace is a data structure for reserving a contiguous address range.
31
32 class ReservedSpace VALUE_OBJ_CLASS_SPEC {
33 friend class VMStructs;
34 private:
35 char* _base;
36 size_t _size;
37 size_t _noaccess_prefix;
38 size_t _alignment;
39 bool _special;
40 bool _executable;
41
42 // ReservedSpace
43 ReservedSpace(char* base, size_t size, size_t alignment, bool special,
44 bool executable);
45 void initialize(size_t size, size_t alignment, bool large,
46 char* requested_address,
47 const size_t noaccess_prefix,
48 bool executable);
49
50 protected:
51 // Create protection page at the beginning of the space.
52 void protect_noaccess_prefix(const size_t size);
53
54 public:
55 // Constructor
56 ReservedSpace();
57 ReservedSpace(size_t size);
58 ReservedSpace(size_t size, size_t alignment, bool large,
59 char* requested_address = NULL,
60 const size_t noaccess_prefix = 0);
61 ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
62
63 // Accessors
64 char* base() const { return _base; }
65 size_t size() const { return _size; }
66 size_t alignment() const { return _alignment; }
67 bool special() const { return _special; }
68 bool executable() const { return _executable; }
69 size_t noaccess_prefix() const { return _noaccess_prefix; }
70 bool is_reserved() const { return _base != NULL; }
71 void release();
72
73 // Splitting
74 ReservedSpace first_part(size_t partition_size, size_t alignment,
75 bool split = false, bool realloc = true);
76 ReservedSpace last_part (size_t partition_size, size_t alignment);
77
78 // These simply call the above using the default alignment.
79 inline ReservedSpace first_part(size_t partition_size,
80 bool split = false, bool realloc = true);
81 inline ReservedSpace last_part (size_t partition_size);
82
83 // Alignment
84 static size_t page_align_size_up(size_t size);
85 static size_t page_align_size_down(size_t size);
86 static size_t allocation_align_size_up(size_t size);
87 static size_t allocation_align_size_down(size_t size);
88 };
89
90 ReservedSpace
91 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
92 {
93 return first_part(partition_size, alignment(), split, realloc);
94 }
95
96 ReservedSpace ReservedSpace::last_part(size_t partition_size)
97 {
98 return last_part(partition_size, alignment());
99 }
100
101 // Class encapsulating behavior specific of memory space reserved for Java heap
102 class ReservedHeapSpace : public ReservedSpace {
103 public:
104 // Constructor
105 ReservedHeapSpace(size_t size, size_t forced_base_alignment,
106 bool large, char* requested_address);
107 };
108
109 // Class encapsulating behavior specific memory space for Code
110 class ReservedCodeSpace : public ReservedSpace {
111 public:
112 // Constructor
113 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
114 };
115
116 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
117
118 class VirtualSpace VALUE_OBJ_CLASS_SPEC {
119 friend class VMStructs;
120 private:
121 // Reserved area
122 char* _low_boundary;
123 char* _high_boundary;
124
125 // Committed area
126 char* _low;
127 char* _high;
128
129 // The entire space has been committed and pinned in memory, no
130 // os::commit_memory() or os::uncommit_memory().
131 bool _special;
132
133 // Need to know if commit should be executable.
134 bool _executable;
135
136 // MPSS Support
137 // Each virtualspace region has a lower, middle, and upper region.
138 // Each region has an end boundary and a high pointer which is the
139 // high water mark for the last allocated byte.
140 // The lower and upper unaligned to LargePageSizeInBytes uses default page.
141 // size. The middle region uses large page size.
142 char* _lower_high;
143 char* _middle_high;
144 char* _upper_high;
145
146 char* _lower_high_boundary;
147 char* _middle_high_boundary;
148 char* _upper_high_boundary;
149
150 size_t _lower_alignment;
151 size_t _middle_alignment;
152 size_t _upper_alignment;
153
154 // MPSS Accessors
155 char* lower_high() const { return _lower_high; }
156 char* middle_high() const { return _middle_high; }
157 char* upper_high() const { return _upper_high; }
158
159 char* lower_high_boundary() const { return _lower_high_boundary; }
160 char* middle_high_boundary() const { return _middle_high_boundary; }
161 char* upper_high_boundary() const { return _upper_high_boundary; }
162
163 size_t lower_alignment() const { return _lower_alignment; }
164 size_t middle_alignment() const { return _middle_alignment; }
165 size_t upper_alignment() const { return _upper_alignment; }
166
167 public:
168 // Committed area
169 char* low() const { return _low; }
170 char* high() const { return _high; }
171
172 // Reserved area
173 char* low_boundary() const { return _low_boundary; }
174 char* high_boundary() const { return _high_boundary; }
175
176 bool special() const { return _special; }
177
178 public:
179 // Initialization
180 VirtualSpace();
181 bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity);
182 bool initialize(ReservedSpace rs, size_t committed_byte_size);
183
184 // Destruction
185 ~VirtualSpace();
186
187 // Reserved memory
188 size_t reserved_size() const;
189 // Actually committed OS memory
190 size_t actual_committed_size() const;
191 // Memory used/expanded in this virtual space
192 size_t committed_size() const;
193 // Memory left to use/expand in this virtual space
194 size_t uncommitted_size() const;
195
196 bool contains(const void* p) const;
197
198 // Operations
199 // returns true on success, false otherwise
200 bool expand_by(size_t bytes, bool pre_touch = false);
201 void shrink_by(size_t bytes);
202 void release();
203
204 void check_for_contiguity() PRODUCT_RETURN;
205
206 // Debugging
207 void print_on(outputStream* out) PRODUCT_RETURN;
208 void print();
209 };
210
211 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP