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();
94 ReservedSpace(size_t size);
95 ReservedSpace(size_t size, size_t alignment, bool large,
96 char* requested_address = NULL,
97 const size_t noaccess_prefix = 0);
98 ReservedSpace(const size_t prefix_size, const size_t prefix_align,
99 const size_t suffix_size, const size_t suffix_align,
100 char* requested_address,
101 const size_t noaccess_prefix = 0);
102 ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
103
104 // Accessors
105 char* base() const { return _base; }
106 size_t size() const { return _size; }
107 size_t alignment() const { return _alignment; }
108 bool special() const { return _special; }
109 bool executable() const { return _executable; }
110 size_t noaccess_prefix() const { return _noaccess_prefix; }
111 bool is_reserved() const { return _base != NULL; }
112 void release();
113
114 // Splitting
115 ReservedSpace first_part(size_t partition_size, size_t alignment,
116 bool split = false, bool realloc = true);
117 ReservedSpace last_part (size_t partition_size, size_t alignment);
118
119 // These simply call the above using the default alignment.
120 inline ReservedSpace first_part(size_t partition_size,
121 bool split = false, bool realloc = true);
122 inline ReservedSpace last_part (size_t partition_size);
123
124 // Alignment
125 static size_t page_align_size_up(size_t size);
126 static size_t page_align_size_down(size_t size);
127 static size_t allocation_align_size_up(size_t size);
128 static size_t allocation_align_size_down(size_t size);
129 };
130
131 ReservedSpace
132 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
133 {
134 return first_part(partition_size, alignment(), split, realloc);
135 }
136
137 ReservedSpace ReservedSpace::last_part(size_t partition_size)
138 {
139 return last_part(partition_size, alignment());
140 }
141
142 // Class encapsulating behavior specific of memory space reserved for Java heap
143 class ReservedHeapSpace : public ReservedSpace {
144 public:
145 // Constructor
146 ReservedHeapSpace(size_t size, size_t forced_base_alignment,
147 bool large, char* requested_address);
148 ReservedHeapSpace(const size_t prefix_size, const size_t prefix_align,
149 const size_t suffix_size, const size_t suffix_align,
150 char* requested_address);
151 };
152
153 // Class encapsulating behavior specific memory space for Code
154 class ReservedCodeSpace : public ReservedSpace {
155 public:
156 // Constructor
157 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
158 };
159
160 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
161
162 class VirtualSpace VALUE_OBJ_CLASS_SPEC {
163 friend class VMStructs;
164 private:
165 // Reserved area
166 char* _low_boundary;
167 char* _high_boundary;
168
169 // Committed area
170 char* _low;
171 char* _high;
172
173 // The entire space has been committed and pinned in memory, no
174 // os::commit_memory() or os::uncommit_memory().
175 bool _special;
176
177 // Need to know if commit should be executable.
178 bool _executable;
179
180 // MPSS Support
181 // Each virtualspace region has a lower, middle, and upper region.
182 // Each region has an end boundary and a high pointer which is the
183 // high water mark for the last allocated byte.
184 // The lower and upper unaligned to LargePageSizeInBytes uses default page.
185 // size. The middle region uses large page size.
186 char* _lower_high;
187 char* _middle_high;
188 char* _upper_high;
189
190 char* _lower_high_boundary;
191 char* _middle_high_boundary;
192 char* _upper_high_boundary;
193
194 size_t _lower_alignment;
195 size_t _middle_alignment;
196 size_t _upper_alignment;
197
198 // MPSS Accessors
199 char* lower_high() const { return _lower_high; }
200 char* middle_high() const { return _middle_high; }
201 char* upper_high() const { return _upper_high; }
202
203 char* lower_high_boundary() const { return _lower_high_boundary; }
204 char* middle_high_boundary() const { return _middle_high_boundary; }
205 char* upper_high_boundary() const { return _upper_high_boundary; }
206
207 size_t lower_alignment() const { return _lower_alignment; }
208 size_t middle_alignment() const { return _middle_alignment; }
209 size_t upper_alignment() const { return _upper_alignment; }
210
211 public:
212 // Committed area
213 char* low() const { return _low; }
214 char* high() const { return _high; }
215
216 // Reserved area
217 char* low_boundary() const { return _low_boundary; }
218 char* high_boundary() const { return _high_boundary; }
219
220 bool special() const { return _special; }
221
222 public:
223 // Initialization
224 VirtualSpace();
225 bool initialize(ReservedSpace rs, size_t committed_byte_size);
226
227 // Destruction
228 ~VirtualSpace();
229
230 // Testers (all sizes are byte sizes)
231 size_t committed_size() const;
232 size_t reserved_size() const;
233 size_t uncommitted_size() const;
234 bool contains(const void* p) const;
235
236 // Operations
237 // returns true on success, false otherwise
238 bool expand_by(size_t bytes, bool pre_touch = false);
239 void shrink_by(size_t bytes);
240 void release();
241
242 void check_for_contiguity() PRODUCT_RETURN;
243
244 // Debugging
245 void print() PRODUCT_RETURN;
246 };
247
248 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP