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