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 protected:
35 char* _base;
36 size_t _size;
37 size_t _noaccess_prefix;
38 size_t _alignment;
39 bool _special;
40 private:
41 bool _executable;
42
43 // ReservedSpace
44 ReservedSpace(char* base, size_t size, size_t alignment, bool special,
45 bool executable);
46 protected:
47 void initialize(size_t size, size_t alignment, bool large,
48 char* requested_address,
49 bool executable);
50
51 public:
52 // Constructor
53 ReservedSpace();
54 ReservedSpace(size_t size);
55 ReservedSpace(size_t size, size_t alignment, bool large,
56 char* requested_address = NULL);
57 ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
58
59 // Accessors
60 char* base() const { return _base; }
61 size_t size() const { return _size; }
62 size_t alignment() const { return _alignment; }
63 bool special() const { return _special; }
64 bool executable() const { return _executable; }
65 size_t noaccess_prefix() const { return _noaccess_prefix; }
66 bool is_reserved() const { return _base != NULL; }
67 void release();
68
69 // Splitting
70 ReservedSpace first_part(size_t partition_size, size_t alignment,
71 bool split = false, bool realloc = true);
72 ReservedSpace last_part (size_t partition_size, size_t alignment);
73
74 // These simply call the above using the default alignment.
75 inline ReservedSpace first_part(size_t partition_size,
76 bool split = false, bool realloc = true);
77 inline ReservedSpace last_part (size_t partition_size);
78
79 // Alignment
80 static size_t page_align_size_up(size_t size);
81 static size_t page_align_size_down(size_t size);
82 static size_t allocation_align_size_up(size_t size);
83 static size_t allocation_align_size_down(size_t size);
84 };
85
86 ReservedSpace
87 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
88 {
89 return first_part(partition_size, alignment(), split, realloc);
90 }
91
92 ReservedSpace ReservedSpace::last_part(size_t partition_size)
93 {
94 return last_part(partition_size, alignment());
95 }
96
97 // Class encapsulating behavior specific of memory space reserved for Java heap.
98 class ReservedHeapSpace : public ReservedSpace {
99 private:
100 void try_reserve_heap(size_t size, size_t alignment, bool large,
101 char *requested_address);
102 void try_reserve_range(char *highest_start, char *lowest_start,
103 size_t attach_point_alignment, char *aligned_HBMA,
104 char *upper_bound, size_t size, size_t alignment, bool large);
105 void initialize_compressed_heap(const size_t size, size_t alignment, bool large);
106 // Create protection page at the beginning of the space.
107 void establish_noaccess_prefix();
108 public:
109 // Constructor. Tries to find a heap that is good for compressed oops.
110 ReservedHeapSpace(size_t size, size_t forced_base_alignment, bool large);
111 // Returns the base to be used for compression, i.e. so that null can be
112 // encoded safely and implicit null checks can work.
113 char *compressed_oop_base() { return _base - _noaccess_prefix; }
114 };
115
116 // Class encapsulating behavior specific memory space for Code
117 class ReservedCodeSpace : public ReservedSpace {
118 public:
119 // Constructor
120 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
121 };
122
123 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
124
125 class VirtualSpace VALUE_OBJ_CLASS_SPEC {
126 friend class VMStructs;
127 private:
128 // Reserved area
129 char* _low_boundary;
130 char* _high_boundary;
131
132 // Committed area
133 char* _low;
134 char* _high;
135
136 // The entire space has been committed and pinned in memory, no
137 // os::commit_memory() or os::uncommit_memory().
138 bool _special;
139
140 // Need to know if commit should be executable.
141 bool _executable;
142
143 // MPSS Support
144 // Each virtualspace region has a lower, middle, and upper region.
145 // Each region has an end boundary and a high pointer which is the
146 // high water mark for the last allocated byte.
147 // The lower and upper unaligned to LargePageSizeInBytes uses default page.
148 // size. The middle region uses large page size.
149 char* _lower_high;
150 char* _middle_high;
151 char* _upper_high;
152
153 char* _lower_high_boundary;
154 char* _middle_high_boundary;
155 char* _upper_high_boundary;
156
157 size_t _lower_alignment;
158 size_t _middle_alignment;
159 size_t _upper_alignment;
160
161 // MPSS Accessors
162 char* lower_high() const { return _lower_high; }
163 char* middle_high() const { return _middle_high; }
164 char* upper_high() const { return _upper_high; }
165
166 char* lower_high_boundary() const { return _lower_high_boundary; }
167 char* middle_high_boundary() const { return _middle_high_boundary; }
168 char* upper_high_boundary() const { return _upper_high_boundary; }
169
170 size_t lower_alignment() const { return _lower_alignment; }
171 size_t middle_alignment() const { return _middle_alignment; }
172 size_t upper_alignment() const { return _upper_alignment; }
173
174 public:
175 // Committed area
176 char* low() const { return _low; }
177 char* high() const { return _high; }
178
179 // Reserved area
180 char* low_boundary() const { return _low_boundary; }
181 char* high_boundary() const { return _high_boundary; }
182
183 bool special() const { return _special; }
184
185 public:
186 // Initialization
187 VirtualSpace();
188 bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity);
189 bool initialize(ReservedSpace rs, size_t committed_byte_size);
190
191 // Destruction
192 ~VirtualSpace();
193
194 // Reserved memory
195 size_t reserved_size() const;
196 // Actually committed OS memory
197 size_t actual_committed_size() const;
198 // Memory used/expanded in this virtual space
199 size_t committed_size() const;
200 // Memory left to use/expand in this virtual space
201 size_t uncommitted_size() const;
202
203 bool contains(const void* p) const;
204
205 // Operations
206 // returns true on success, false otherwise
207 bool expand_by(size_t bytes, bool pre_touch = false);
208 void shrink_by(size_t bytes);
209 void release();
210
211 void check_for_contiguity() PRODUCT_RETURN;
212
213 // Debugging
214 void print_on(outputStream* out) PRODUCT_RETURN;
215 void print();
216 };
217
218 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP