1 /*
2 * Copyright (c) 1997, 2009, 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 // ReservedSpace is a data structure for reserving a contiguous address range.
26
27 class ReservedSpace VALUE_OBJ_CLASS_SPEC {
28 friend class VMStructs;
29 private:
30 char* _base;
31 size_t _size;
32 size_t _noaccess_prefix;
33 size_t _alignment;
34 bool _special;
35 bool _executable;
36
37 // ReservedSpace
38 ReservedSpace(char* base, size_t size, size_t alignment, bool special,
39 bool executable);
40 void initialize(size_t size, size_t alignment, bool large,
41 char* requested_address,
42 const size_t noaccess_prefix,
43 bool executable);
44
45 // Release parts of an already-reserved memory region [addr, addr + len) to
46 // get a new region that has "compound alignment." Return the start of the
47 // resulting region, or NULL on failure.
48 //
49 // The region is logically divided into a prefix and a suffix. The prefix
50 // starts at the result address, which is aligned to prefix_align. The suffix
51 // starts at result address + prefix_size, which is aligned to suffix_align.
52 // The total size of the result region is size prefix_size + suffix_size.
53 char* align_reserved_region(char* addr, const size_t len,
54 const size_t prefix_size,
55 const size_t prefix_align,
56 const size_t suffix_size,
57 const size_t suffix_align);
58
59 // Reserve memory, call align_reserved_region() to alignment it and return the
60 // result.
61 char* reserve_and_align(const size_t reserve_size,
62 const size_t prefix_size,
63 const size_t prefix_align,
64 const size_t suffix_size,
65 const size_t suffix_align);
66
67 protected:
68 // Create protection page at the beginning of the space.
69 void protect_noaccess_prefix(const size_t size);
70
71 public:
72 // Constructor
73 ReservedSpace(size_t size);
74 ReservedSpace(size_t size, size_t alignment, bool large,
75 char* requested_address = NULL,
76 const size_t noaccess_prefix = 0);
77 ReservedSpace(const size_t prefix_size, const size_t prefix_align,
78 const size_t suffix_size, const size_t suffix_align,
79 char* requested_address,
80 const size_t noaccess_prefix = 0);
81 ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
82
83 // Accessors
84 char* base() const { return _base; }
85 size_t size() const { return _size; }
86 size_t alignment() const { return _alignment; }
87 bool special() const { return _special; }
88 bool executable() const { return _executable; }
89 size_t noaccess_prefix() const { return _noaccess_prefix; }
90 bool is_reserved() const { return _base != NULL; }
91 void release();
92
93 // Splitting
94 ReservedSpace first_part(size_t partition_size, size_t alignment,
95 bool split = false, bool realloc = true);
96 ReservedSpace last_part (size_t partition_size, size_t alignment);
97
98 // These simply call the above using the default alignment.
99 inline ReservedSpace first_part(size_t partition_size,
100 bool split = false, bool realloc = true);
101 inline ReservedSpace last_part (size_t partition_size);
102
103 // Alignment
104 static size_t page_align_size_up(size_t size);
105 static size_t page_align_size_down(size_t size);
106 static size_t allocation_align_size_up(size_t size);
107 static size_t allocation_align_size_down(size_t size);
108 };
109
110 ReservedSpace
111 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
112 {
113 return first_part(partition_size, alignment(), split, realloc);
114 }
115
116 ReservedSpace ReservedSpace::last_part(size_t partition_size)
117 {
118 return last_part(partition_size, alignment());
119 }
120
121 // Class encapsulating behavior specific of memory space reserved for Java heap
122 class ReservedHeapSpace : public ReservedSpace {
123 public:
124 // Constructor
125 ReservedHeapSpace(size_t size, size_t forced_base_alignment,
126 bool large, char* requested_address);
127 ReservedHeapSpace(const size_t prefix_size, const size_t prefix_align,
128 const size_t suffix_size, const size_t suffix_align,
129 char* requested_address);
130 };
131
132 // Class encapsulating behavior specific memory space for Code
133 class ReservedCodeSpace : public ReservedSpace {
134 public:
135 // Constructor
136 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
137 };
138
139 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
140
141 class VirtualSpace VALUE_OBJ_CLASS_SPEC {
142 friend class VMStructs;
143 private:
144 // Reserved area
145 char* _low_boundary;
146 char* _high_boundary;
147
148 // Committed area
149 char* _low;
150 char* _high;
151
152 // The entire space has been committed and pinned in memory, no
153 // os::commit_memory() or os::uncommit_memory().
154 bool _special;
155
156 // Need to know if commit should be executable.
157 bool _executable;
158
159 // MPSS Support
160 // Each virtualspace region has a lower, middle, and upper region.
161 // Each region has an end boundary and a high pointer which is the
162 // high water mark for the last allocated byte.
163 // The lower and upper unaligned to LargePageSizeInBytes uses default page.
164 // size. The middle region uses large page size.
165 char* _lower_high;
166 char* _middle_high;
167 char* _upper_high;
168
169 char* _lower_high_boundary;
170 char* _middle_high_boundary;
171 char* _upper_high_boundary;
172
173 size_t _lower_alignment;
174 size_t _middle_alignment;
175 size_t _upper_alignment;
176
177 // MPSS Accessors
178 char* lower_high() const { return _lower_high; }
179 char* middle_high() const { return _middle_high; }
180 char* upper_high() const { return _upper_high; }
181
182 char* lower_high_boundary() const { return _lower_high_boundary; }
183 char* middle_high_boundary() const { return _middle_high_boundary; }
184 char* upper_high_boundary() const { return _upper_high_boundary; }
185
186 size_t lower_alignment() const { return _lower_alignment; }
187 size_t middle_alignment() const { return _middle_alignment; }
188 size_t upper_alignment() const { return _upper_alignment; }
189
190 public:
191 // Committed area
192 char* low() const { return _low; }
193 char* high() const { return _high; }
194
195 // Reserved area
196 char* low_boundary() const { return _low_boundary; }
197 char* high_boundary() const { return _high_boundary; }
198
199 bool special() const { return _special; }
200
201 public:
202 // Initialization
203 VirtualSpace();
204 bool initialize(ReservedSpace rs, size_t committed_byte_size);
205
206 // Destruction
207 ~VirtualSpace();
208
209 // Testers (all sizes are byte sizes)
210 size_t committed_size() const;
211 size_t reserved_size() const;
212 size_t uncommitted_size() const;
213 bool contains(const void* p) const;
214
215 // Operations
216 // returns true on success, false otherwise
217 bool expand_by(size_t bytes, bool pre_touch = false);
218 void shrink_by(size_t bytes);
219 void release();
220
221 void check_for_contiguity() PRODUCT_RETURN;
222
223 // Debugging
224 void print() PRODUCT_RETURN;
225 };