1 /*
2 * Copyright (c) 1997, 2010, 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
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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 // Release parts of an already-reserved memory region [addr, addr + len) to
51 // get a new region that has "compound alignment." Return the start of the
52 // resulting region, or NULL on failure.
53 //
54 // The region is logically divided into a prefix and a suffix. The prefix
55 // starts at the result address, which is aligned to prefix_align. The suffix
56 // starts at result address + prefix_size, which is aligned to suffix_align.
57 // The total size of the result region is size prefix_size + suffix_size.
58 char* align_reserved_region(char* addr, const size_t len,
59 const size_t prefix_size,
60 const size_t prefix_align,
61 const size_t suffix_size,
62 const size_t suffix_align);
63
64 // Reserve memory, call align_reserved_region() to alignment it and return the
65 // result.
66 char* reserve_and_align(const size_t reserve_size,
67 const size_t prefix_size,
68 const size_t prefix_align,
69 const size_t suffix_size,
70 const size_t suffix_align);
71
72 protected:
73 // Create protection page at the beginning of the space.
74 void protect_noaccess_prefix(const size_t size);
75
76 public:
77 // Constructor
78 ReservedSpace(size_t size);
79 ReservedSpace(size_t size, size_t alignment, bool large,
80 char* requested_address = NULL,
81 const size_t noaccess_prefix = 0);
82 ReservedSpace(const size_t prefix_size, const size_t prefix_align,
83 const size_t suffix_size, const size_t suffix_align,
84 char* requested_address,
85 const size_t noaccess_prefix = 0);
86 ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
87
88 // Accessors
89 char* base() const { return _base; }
90 size_t size() const { return _size; }
91 size_t alignment() const { return _alignment; }
92 bool special() const { return _special; }
93 bool executable() const { return _executable; }
94 size_t noaccess_prefix() const { return _noaccess_prefix; }
95 bool is_reserved() const { return _base != NULL; }
96 void release();
97
98 // Splitting
99 ReservedSpace first_part(size_t partition_size, size_t alignment,
100 bool split = false, bool realloc = true);
101 ReservedSpace last_part (size_t partition_size, size_t alignment);
102
103 // These simply call the above using the default alignment.
104 inline ReservedSpace first_part(size_t partition_size,
105 bool split = false, bool realloc = true);
106 inline ReservedSpace last_part (size_t partition_size);
107
108 // Alignment
109 static size_t page_align_size_up(size_t size);
110 static size_t page_align_size_down(size_t size);
111 static size_t allocation_align_size_up(size_t size);
112 static size_t allocation_align_size_down(size_t size);
113 };
114
115 ReservedSpace
116 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
117 {
118 return first_part(partition_size, alignment(), split, realloc);
119 }
120
121 ReservedSpace ReservedSpace::last_part(size_t partition_size)
122 {
123 return last_part(partition_size, alignment());
124 }
125
126 // Class encapsulating behavior specific of memory space reserved for Java heap
127 class ReservedHeapSpace : public ReservedSpace {
128 public:
129 // Constructor
130 ReservedHeapSpace(size_t size, size_t forced_base_alignment,
131 bool large, char* requested_address);
132 ReservedHeapSpace(const size_t prefix_size, const size_t prefix_align,
133 const size_t suffix_size, const size_t suffix_align,
134 char* requested_address);
135 };
136
137 // Class encapsulating behavior specific memory space for Code
138 class ReservedCodeSpace : public ReservedSpace {
139 public:
140 // Constructor
141 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
142 };
143
144 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
145
146 class VirtualSpace VALUE_OBJ_CLASS_SPEC {
147 friend class VMStructs;
148 private:
149 // Reserved area
150 char* _low_boundary;
151 char* _high_boundary;
152
153 // Committed area
154 char* _low;
155 char* _high;
156
157 // The entire space has been committed and pinned in memory, no
158 // os::commit_memory() or os::uncommit_memory().
159 bool _special;
160
161 // Need to know if commit should be executable.
162 bool _executable;
163
164 // MPSS Support
165 // Each virtualspace region has a lower, middle, and upper region.
166 // Each region has an end boundary and a high pointer which is the
167 // high water mark for the last allocated byte.
168 // The lower and upper unaligned to LargePageSizeInBytes uses default page.
169 // size. The middle region uses large page size.
170 char* _lower_high;
171 char* _middle_high;
172 char* _upper_high;
173
174 char* _lower_high_boundary;
175 char* _middle_high_boundary;
176 char* _upper_high_boundary;
177
178 size_t _lower_alignment;
179 size_t _middle_alignment;
180 size_t _upper_alignment;
181
182 // MPSS Accessors
183 char* lower_high() const { return _lower_high; }
184 char* middle_high() const { return _middle_high; }
185 char* upper_high() const { return _upper_high; }
186
187 char* lower_high_boundary() const { return _lower_high_boundary; }
188 char* middle_high_boundary() const { return _middle_high_boundary; }
189 char* upper_high_boundary() const { return _upper_high_boundary; }
190
191 size_t lower_alignment() const { return _lower_alignment; }
192 size_t middle_alignment() const { return _middle_alignment; }
193 size_t upper_alignment() const { return _upper_alignment; }
194
195 public:
196 // Committed area
197 char* low() const { return _low; }
198 char* high() const { return _high; }
199
200 // Reserved area
201 char* low_boundary() const { return _low_boundary; }
202 char* high_boundary() const { return _high_boundary; }
203
204 bool special() const { return _special; }
205
206 public:
207 // Initialization
208 VirtualSpace();
209 bool initialize(ReservedSpace rs, size_t committed_byte_size);
210
211 // Destruction
212 ~VirtualSpace();
213
214 // Testers (all sizes are byte sizes)
215 size_t committed_size() const;
216 size_t reserved_size() const;
217 size_t uncommitted_size() const;
218 bool contains(const void* p) const;
219
220 // Operations
221 // returns true on success, false otherwise
222 bool expand_by(size_t bytes, bool pre_touch = false);
223 void shrink_by(size_t bytes);
224 void release();
225
226 void check_for_contiguity() PRODUCT_RETURN;
227
228 // Debugging
229 void print() PRODUCT_RETURN;
230 };
231
232 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP