1 /*
2 * Copyright (c) 1997, 2015, 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 // Initialize the reserved space with the given size. If prefer_large_pages is
55 // set, if the given size warrants use of large pages, try to force them by
56 // passing an alignment restriction further down. This may waste some space
57 // if the given size is not aligned, as the reservation will be aligned up
58 // to large page alignment.
59 ReservedSpace(size_t size, bool prefer_large_pages = false);
60 ReservedSpace(size_t size, size_t alignment, bool large,
61 char* requested_address = NULL);
62 ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
63
64 // Accessors
65 char* base() const { return _base; }
66 size_t size() const { return _size; }
67 size_t alignment() const { return _alignment; }
68 bool special() const { return _special; }
69 bool executable() const { return _executable; }
70 size_t noaccess_prefix() const { return _noaccess_prefix; }
71 bool is_reserved() const { return _base != NULL; }
72 void release();
73
74 // Splitting
75 ReservedSpace first_part(size_t partition_size, size_t alignment,
76 bool split = false, bool realloc = true);
77 ReservedSpace last_part (size_t partition_size, size_t alignment);
78
79 // These simply call the above using the default alignment.
80 inline ReservedSpace first_part(size_t partition_size,
81 bool split = false, bool realloc = true);
82 inline ReservedSpace last_part (size_t partition_size);
83
84 // Alignment
85 static size_t page_align_size_up(size_t size);
86 static size_t page_align_size_down(size_t size);
87 static size_t allocation_align_size_up(size_t size);
88 static size_t allocation_align_size_down(size_t size);
89 };
90
91 ReservedSpace
92 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
93 {
94 return first_part(partition_size, alignment(), split, realloc);
95 }
96
97 ReservedSpace ReservedSpace::last_part(size_t partition_size)
98 {
99 return last_part(partition_size, alignment());
100 }
101
102 // Class encapsulating behavior specific of memory space reserved for Java heap.
103 class ReservedHeapSpace : public ReservedSpace {
104 private:
105 void try_reserve_heap(size_t size, size_t alignment, bool large,
106 char *requested_address);
107 void try_reserve_range(char *highest_start, char *lowest_start,
108 size_t attach_point_alignment, char *aligned_HBMA,
109 char *upper_bound, size_t size, size_t alignment, bool large);
110 void initialize_compressed_heap(const size_t size, size_t alignment, bool large);
111 // Create protection page at the beginning of the space.
112 void establish_noaccess_prefix();
113 public:
114 // Constructor. Tries to find a heap that is good for compressed oops.
115 ReservedHeapSpace(size_t size, size_t forced_base_alignment, bool large);
116 // Returns the base to be used for compression, i.e. so that null can be
117 // encoded safely and implicit null checks can work.
118 char *compressed_oop_base() { return _base - _noaccess_prefix; }
119 };
120
121 // Class encapsulating behavior specific memory space for Code
122 class ReservedCodeSpace : public ReservedSpace {
123 public:
124 // Constructor
125 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
126 };
127
128 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
129
130 class VirtualSpace VALUE_OBJ_CLASS_SPEC {
131 friend class VMStructs;
132 private:
133 // Reserved area
134 char* _low_boundary;
135 char* _high_boundary;
136
137 // Committed area
138 char* _low;
139 char* _high;
140
141 // The entire space has been committed and pinned in memory, no
142 // os::commit_memory() or os::uncommit_memory().
143 bool _special;
144
145 // Need to know if commit should be executable.
146 bool _executable;
147
148 // MPSS Support
149 // Each virtualspace region has a lower, middle, and upper region.
150 // Each region has an end boundary and a high pointer which is the
151 // high water mark for the last allocated byte.
152 // The lower and upper unaligned to LargePageSizeInBytes uses default page.
153 // size. The middle region uses large page size.
154 char* _lower_high;
155 char* _middle_high;
156 char* _upper_high;
157
158 char* _lower_high_boundary;
159 char* _middle_high_boundary;
160 char* _upper_high_boundary;
161
162 size_t _lower_alignment;
163 size_t _middle_alignment;
164 size_t _upper_alignment;
165
166 // MPSS Accessors
167 char* lower_high() const { return _lower_high; }
168 char* middle_high() const { return _middle_high; }
169 char* upper_high() const { return _upper_high; }
170
171 char* lower_high_boundary() const { return _lower_high_boundary; }
172 char* middle_high_boundary() const { return _middle_high_boundary; }
173 char* upper_high_boundary() const { return _upper_high_boundary; }
174
175 size_t lower_alignment() const { return _lower_alignment; }
176 size_t middle_alignment() const { return _middle_alignment; }
177 size_t upper_alignment() const { return _upper_alignment; }
178
179 public:
180 // Committed area
181 char* low() const { return _low; }
182 char* high() const { return _high; }
183
184 // Reserved area
185 char* low_boundary() const { return _low_boundary; }
186 char* high_boundary() const { return _high_boundary; }
187
188 bool special() const { return _special; }
189
190 public:
191 // Initialization
192 VirtualSpace();
193 bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity);
194 bool initialize(ReservedSpace rs, size_t committed_byte_size);
195
196 // Destruction
197 ~VirtualSpace();
198
199 // Reserved memory
200 size_t reserved_size() const;
201 // Actually committed OS memory
202 size_t actual_committed_size() const;
203 // Memory used/expanded in this virtual space
204 size_t committed_size() const;
205 // Memory left to use/expand in this virtual space
206 size_t uncommitted_size() const;
207
208 bool contains(const void* p) const;
209
210 // Operations
211 // returns true on success, false otherwise
212 bool expand_by(size_t bytes, bool pre_touch = false);
213 void shrink_by(size_t bytes);
214 void release();
215
216 void check_for_contiguity() PRODUCT_RETURN;
217
218 // Debugging
219 void print_on(outputStream* out) PRODUCT_RETURN;
220 void print();
221 };
222
223 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP