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
21 * questions.
22 *
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
39 // The base and size prior to any alignment done by this class; used only on
40 // systems that cannot release part of a region.
41 char* _raw_base;
42 size_t _raw_size;
43
44 size_t _alignment;
45 bool _special;
46 bool _executable;
47
48 // ReservedSpace
49 ReservedSpace(char* base, size_t size, size_t alignment, bool special,
50 bool executable);
51
52 bool failed_to_reserve_as_requested(char* base, char* requested_address,
53 const size_t size, bool special);
54 void initialize(size_t size, size_t alignment, bool large,
55 char* requested_address,
56 const size_t noaccess_prefix,
57 bool executable);
58
59 inline void set_raw_base_and_size(char * const raw_base, size_t raw_size);
60
61 // Release virtual address space. If alignment was done, use the saved
62 // address and size when releasing.
63 void release_memory(char * default_addr, size_t default_size);
64
65 // Release parts of an already-reserved memory region [addr, addr + len) to
66 // get a new region that has "compound alignment." Return the start of the
67 // resulting region, or NULL on failure.
68 //
69 // The region is logically divided into a prefix and a suffix. The prefix
70 // starts at the result address, which is aligned to prefix_align. The suffix
71 // starts at result address + prefix_size, which is aligned to suffix_align.
72 // The total size of the result region is size prefix_size + suffix_size.
73 char* align_reserved_region(char* addr, const size_t len,
74 const size_t prefix_size,
75 const size_t prefix_align,
76 const size_t suffix_size,
77 const size_t suffix_align);
78
79 // Reserve memory, call align_reserved_region() to alignment it and return the
80 // result.
81 char* reserve_and_align(const size_t reserve_size,
82 const size_t prefix_size,
83 const size_t prefix_align,
84 const size_t suffix_size,
85 const size_t suffix_align);
86
87 protected:
88 // Create protection page at the beginning of the space.
89 void protect_noaccess_prefix(const size_t size);
90
91 public:
92 // Constructor
93 ReservedSpace(size_t size);
94 ReservedSpace(size_t size, size_t alignment, bool large,
95 char* requested_address = NULL,
96 const size_t noaccess_prefix = 0);
97 ReservedSpace(const size_t prefix_size, const size_t prefix_align,
98 const size_t suffix_size, const size_t suffix_align,
99 char* requested_address,
100 const size_t noaccess_prefix = 0);
101 ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
102
103 // Accessors
104 char* base() const { return _base; }
105 size_t size() const { return _size; }
106 size_t alignment() const { return _alignment; }
107 bool special() const { return _special; }
108 bool executable() const { return _executable; }
109 size_t noaccess_prefix() const { return _noaccess_prefix; }
110 bool is_reserved() const { return _base != NULL; }
111 void release();
112
113 // Splitting
114 ReservedSpace first_part(size_t partition_size, size_t alignment,
115 bool split = false, bool realloc = true);
116 ReservedSpace last_part (size_t partition_size, size_t alignment);
117
118 // These simply call the above using the default alignment.
119 inline ReservedSpace first_part(size_t partition_size,
120 bool split = false, bool realloc = true);
121 inline ReservedSpace last_part (size_t partition_size);
122
123 // Alignment
124 static size_t page_align_size_up(size_t size);
125 static size_t page_align_size_down(size_t size);
126 static size_t allocation_align_size_up(size_t size);
127 static size_t allocation_align_size_down(size_t size);
128 };
129
130 ReservedSpace
131 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
132 {
133 return first_part(partition_size, alignment(), split, realloc);
134 }
135
136 ReservedSpace ReservedSpace::last_part(size_t partition_size)
137 {
138 return last_part(partition_size, alignment());
139 }
140
141 // Class encapsulating behavior specific of memory space reserved for Java heap
142 class ReservedHeapSpace : public ReservedSpace {
143 public:
144 // Constructor
145 ReservedHeapSpace(size_t size, size_t forced_base_alignment,
146 bool large, char* requested_address);
147 ReservedHeapSpace(const size_t prefix_size, const size_t prefix_align,
148 const size_t suffix_size, const size_t suffix_align,
149 char* requested_address);
150 };
151
152 // Class encapsulating behavior specific memory space for Code
153 class ReservedCodeSpace : public ReservedSpace {
154 public:
155 // Constructor
156 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
157 };
158
159 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
160
161 class VirtualSpace VALUE_OBJ_CLASS_SPEC {
162 friend class VMStructs;
163 private:
164 // Reserved area
165 char* _low_boundary;
166 char* _high_boundary;
167
168 // Committed area
169 char* _low;
170 char* _high;
171
172 // The entire space has been committed and pinned in memory, no
173 // os::commit_memory() or os::uncommit_memory().
174 bool _special;
175
176 // Need to know if commit should be executable.
177 bool _executable;
178
179 // MPSS Support
180 // Each virtualspace region has a lower, middle, and upper region.
181 // Each region has an end boundary and a high pointer which is the
182 // high water mark for the last allocated byte.
183 // The lower and upper unaligned to LargePageSizeInBytes uses default page.
184 // size. The middle region uses large page size.
185 char* _lower_high;
186 char* _middle_high;
187 char* _upper_high;
188
189 char* _lower_high_boundary;
190 char* _middle_high_boundary;
191 char* _upper_high_boundary;
192
193 size_t _lower_alignment;
194 size_t _middle_alignment;
195 size_t _upper_alignment;
196
197 // MPSS Accessors
198 char* lower_high() const { return _lower_high; }
199 char* middle_high() const { return _middle_high; }
200 char* upper_high() const { return _upper_high; }
201
202 char* lower_high_boundary() const { return _lower_high_boundary; }
203 char* middle_high_boundary() const { return _middle_high_boundary; }
204 char* upper_high_boundary() const { return _upper_high_boundary; }
205
206 size_t lower_alignment() const { return _lower_alignment; }
207 size_t middle_alignment() const { return _middle_alignment; }
208 size_t upper_alignment() const { return _upper_alignment; }
209
210 public:
211 // Committed area
212 char* low() const { return _low; }
213 char* high() const { return _high; }
214
215 // Reserved area
216 char* low_boundary() const { return _low_boundary; }
217 char* high_boundary() const { return _high_boundary; }
218
219 bool special() const { return _special; }
220
221 public:
222 // Initialization
223 VirtualSpace();
224 bool initialize(ReservedSpace rs, size_t committed_byte_size);
225
226 // Destruction
227 ~VirtualSpace();
228
229 // Testers (all sizes are byte sizes)
230 size_t committed_size() const;
231 size_t reserved_size() const;
232 size_t uncommitted_size() const;
233 bool contains(const void* p) const;
234
235 // Operations
236 // returns true on success, false otherwise
237 bool expand_by(size_t bytes, bool pre_touch = false);
238 void shrink_by(size_t bytes);
239 void release();
240
241 void check_for_contiguity() PRODUCT_RETURN;
242
243 // Debugging
244 void print() PRODUCT_RETURN;
245 };
246
247 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP