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 // Initialize the reserved space with the given size. If prefer_large_pages is
58 // set, if the given size warrants use of large pages, try to force them by
59 // passing an alignment restriction further down. This may waste some space
60 // if the given size is not aligned, as the reservation will be aligned up
61 // to large page alignment.
62 ReservedSpace(size_t size, bool prefer_large_pages = false);
63 ReservedSpace(size_t size, size_t alignment, bool large,
64 char* requested_address = NULL,
65 const size_t noaccess_prefix = 0);
66 ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
67
68 // Accessors
69 char* base() const { return _base; }
70 size_t size() const { return _size; }
71 size_t alignment() const { return _alignment; }
72 bool special() const { return _special; }
73 bool executable() const { return _executable; }
74 size_t noaccess_prefix() const { return _noaccess_prefix; }
75 bool is_reserved() const { return _base != NULL; }
76 void release();
77
78 // Splitting
79 ReservedSpace first_part(size_t partition_size, size_t alignment,
80 bool split = false, bool realloc = true);
81 ReservedSpace last_part (size_t partition_size, size_t alignment);
82
83 // These simply call the above using the default alignment.
84 inline ReservedSpace first_part(size_t partition_size,
85 bool split = false, bool realloc = true);
86 inline ReservedSpace last_part (size_t partition_size);
87
88 // Alignment
89 static size_t page_align_size_up(size_t size);
90 static size_t page_align_size_down(size_t size);
91 static size_t allocation_align_size_up(size_t size);
92 static size_t allocation_align_size_down(size_t size);
93 };
94
95 ReservedSpace
96 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
97 {
98 return first_part(partition_size, alignment(), split, realloc);
99 }
100
101 ReservedSpace ReservedSpace::last_part(size_t partition_size)
102 {
103 return last_part(partition_size, alignment());
104 }
105
106 // Class encapsulating behavior specific of memory space reserved for Java heap
107 class ReservedHeapSpace : public ReservedSpace {
108 public:
109 // Constructor
110 ReservedHeapSpace(size_t size, size_t forced_base_alignment,
111 bool large, char* requested_address);
112 };
113
114 // Class encapsulating behavior specific memory space for Code
115 class ReservedCodeSpace : public ReservedSpace {
116 public:
117 // Constructor
118 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
119 };
120
121 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
122
123 class VirtualSpace VALUE_OBJ_CLASS_SPEC {
124 friend class VMStructs;
125 private:
126 // Reserved area
127 char* _low_boundary;
128 char* _high_boundary;
129
130 // Committed area
131 char* _low;
132 char* _high;
133
134 // The entire space has been committed and pinned in memory, no
135 // os::commit_memory() or os::uncommit_memory().
136 bool _special;
137
138 // Need to know if commit should be executable.
139 bool _executable;
140
141 // MPSS Support
142 // Each virtualspace region has a lower, middle, and upper region.
143 // Each region has an end boundary and a high pointer which is the
144 // high water mark for the last allocated byte.
145 // The lower and upper unaligned to LargePageSizeInBytes uses default page.
146 // size. The middle region uses large page size.
147 char* _lower_high;
148 char* _middle_high;
149 char* _upper_high;
150
151 char* _lower_high_boundary;
152 char* _middle_high_boundary;
153 char* _upper_high_boundary;
154
155 size_t _lower_alignment;
156 size_t _middle_alignment;
157 size_t _upper_alignment;
158
159 // MPSS Accessors
160 char* lower_high() const { return _lower_high; }
161 char* middle_high() const { return _middle_high; }
162 char* upper_high() const { return _upper_high; }
163
164 char* lower_high_boundary() const { return _lower_high_boundary; }
165 char* middle_high_boundary() const { return _middle_high_boundary; }
166 char* upper_high_boundary() const { return _upper_high_boundary; }
167
168 size_t lower_alignment() const { return _lower_alignment; }
169 size_t middle_alignment() const { return _middle_alignment; }
170 size_t upper_alignment() const { return _upper_alignment; }
171
172 public:
173 // Committed area
174 char* low() const { return _low; }
175 char* high() const { return _high; }
176
177 // Reserved area
178 char* low_boundary() const { return _low_boundary; }
179 char* high_boundary() const { return _high_boundary; }
180
181 bool special() const { return _special; }
182
183 public:
184 // Initialization
185 VirtualSpace();
186 bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity);
187 bool initialize(ReservedSpace rs, size_t committed_byte_size);
188
189 // Destruction
190 ~VirtualSpace();
191
192 // Reserved memory
193 size_t reserved_size() const;
194 // Actually committed OS memory
195 size_t actual_committed_size() const;
196 // Memory used/expanded in this virtual space
197 size_t committed_size() const;
198 // Memory left to use/expand in this virtual space
199 size_t uncommitted_size() const;
200
201 bool contains(const void* p) const;
202
203 // Operations
204 // returns true on success, false otherwise
205 bool expand_by(size_t bytes, bool pre_touch = false);
206 void shrink_by(size_t bytes);
207 void release();
208
209 void check_for_contiguity() PRODUCT_RETURN;
210
211 // Debugging
212 void print_on(outputStream* out) PRODUCT_RETURN;
213 void print();
214 };
215
216 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP