1 /*
2 * Copyright (c) 1997, 2019, 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
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23 */
24
25 #ifndef SHARE_MEMORY_VIRTUALSPACE_HPP
26 #define SHARE_MEMORY_VIRTUALSPACE_HPP
27
28 #include "memory/memRegion.hpp"
29 #include "utilities/globalDefinitions.hpp"
30
31 class outputStream;
32
33 // ReservedSpace is a data structure for reserving a contiguous address range.
34
35 class ReservedSpace {
36 friend class VMStructs;
37 protected:
38 char* _base;
39 size_t _size;
40 size_t _noaccess_prefix;
41 size_t _alignment;
42 bool _special;
43 int _fd_for_heap;
44 private:
45 bool _executable;
46
47 // ReservedSpace
48 ReservedSpace(char* base, size_t size, size_t alignment, bool special,
49 bool executable);
50 protected:
51 void initialize(size_t size, size_t alignment, bool large,
52 char* requested_address,
53 bool executable);
54
55 public:
56 // Constructor
57 ReservedSpace();
58 // Initialize the reserved space with the given size. If preferred_page_size
59 // is set, use this as minimum page size/alignment. This may waste some space
60 // if the given size is not aligned to that value, as the reservation will be
61 // aligned up to the final alignment in this case.
62 ReservedSpace(size_t size, size_t preferred_page_size = 0);
63 ReservedSpace(size_t size, size_t alignment, bool large,
64 char* requested_address = NULL);
65 ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
66
67 // Accessors
68 char* base() const { return _base; }
69 size_t size() const { return _size; }
70 char* end() const { return _base + _size; }
71 size_t alignment() const { return _alignment; }
72 bool special() const { return _special; }
73 bool executable() const { return _executable; }
74 size_t noaccess_prefix() const { return _noaccess_prefix; }
75 bool is_reserved() const { return _base != NULL; }
76 void release();
77
78 // Splitting
79 ReservedSpace first_part(size_t partition_size, size_t alignment,
80 bool split = false, bool realloc = true);
81 ReservedSpace last_part (size_t partition_size, size_t alignment);
82
83 // These simply call the above using the default alignment.
84 inline ReservedSpace first_part(size_t partition_size,
85 bool split = false, bool realloc = true);
86 inline ReservedSpace last_part (size_t partition_size);
87
88 // Alignment
89 static size_t page_align_size_up(size_t size);
90 static size_t page_align_size_down(size_t size);
91 static size_t allocation_align_size_up(size_t size);
92 bool contains(const void* p) const {
93 return (base() <= ((char*)p)) && (((char*)p) < (base() + size()));
94 }
95 };
96
97 ReservedSpace
98 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
99 {
100 return first_part(partition_size, alignment(), split, realloc);
101 }
102
103 ReservedSpace ReservedSpace::last_part(size_t partition_size)
104 {
105 return last_part(partition_size, alignment());
106 }
107
108 // Class encapsulating behavior specific of memory space reserved for Java heap.
109 class ReservedHeapSpace : public ReservedSpace {
110 private:
111 void try_reserve_heap(size_t size, size_t alignment, bool large,
112 char *requested_address);
113 void try_reserve_range(char *highest_start, char *lowest_start,
114 size_t attach_point_alignment, char *aligned_HBMA,
115 char *upper_bound, size_t size, size_t alignment, bool large);
116 void initialize_compressed_heap(const size_t size, size_t alignment, bool large);
117 // Create protection page at the beginning of the space.
118 void establish_noaccess_prefix();
119 public:
120 // Constructor. Tries to find a heap that is good for compressed oops.
121 // heap_allocation_directory is the path to the backing memory for Java heap. When set, Java heap will be allocated
122 // on the device which is managed by the file system where the directory resides.
123 ReservedHeapSpace(size_t size, size_t forced_base_alignment, bool large, const char* heap_allocation_directory = NULL);
124 // Returns the base to be used for compression, i.e. so that null can be
125 // encoded safely and implicit null checks can work.
126 char *compressed_oop_base() const { return _base - _noaccess_prefix; }
127 MemRegion region() const;
128 };
129
130 // Class encapsulating behavior specific memory space for Code
131 class ReservedCodeSpace : public ReservedSpace {
132 public:
133 // Constructor
134 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
135 };
136
137 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
138
139 class VirtualSpace {
140 friend class VMStructs;
141 private:
142 // Reserved area
143 char* _low_boundary;
144 char* _high_boundary;
145
146 // Committed area
147 char* _low;
148 char* _high;
149
150 // The entire space has been committed and pinned in memory, no
151 // os::commit_memory() or os::uncommit_memory().
152 bool _special;
153
154 // Need to know if commit should be executable.
155 bool _executable;
156
157 // MPSS Support
158 // Each virtualspace region has a lower, middle, and upper region.
159 // Each region has an end boundary and a high pointer which is the
160 // high water mark for the last allocated byte.
161 // The lower and upper unaligned to LargePageSizeInBytes uses default page.
162 // size. The middle region uses large page size.
163 char* _lower_high;
164 char* _middle_high;
165 char* _upper_high;
166
167 char* _lower_high_boundary;
168 char* _middle_high_boundary;
169 char* _upper_high_boundary;
170
171 size_t _lower_alignment;
172 size_t _middle_alignment;
173 size_t _upper_alignment;
174
175 // MPSS Accessors
176 char* lower_high() const { return _lower_high; }
177 char* middle_high() const { return _middle_high; }
178 char* upper_high() const { return _upper_high; }
179
180 char* lower_high_boundary() const { return _lower_high_boundary; }
181 char* middle_high_boundary() const { return _middle_high_boundary; }
182 char* upper_high_boundary() const { return _upper_high_boundary; }
183
184 size_t lower_alignment() const { return _lower_alignment; }
185 size_t middle_alignment() const { return _middle_alignment; }
186 size_t upper_alignment() const { return _upper_alignment; }
187
188 public:
189 // Committed area
190 char* low() const { return _low; }
191 char* high() const { return _high; }
192
193 // Reserved area
194 char* low_boundary() const { return _low_boundary; }
195 char* high_boundary() const { return _high_boundary; }
196
197 #if INCLUDE_AOT
198 // Set boundaries for code section in AOT library.
199 void set_low_boundary(char *p) { _low_boundary = p; }
200 void set_high_boundary(char *p) { _high_boundary = p; }
201 void set_low(char *p) { _low = p; }
202 void set_high(char *p) { _high = p; }
203 #endif
204
205 bool special() const { return _special; }
206
207 public:
208 // Initialization
209 VirtualSpace();
210 bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity);
211 bool initialize(ReservedSpace rs, size_t committed_byte_size);
212
213 // Destruction
214 ~VirtualSpace();
215
216 // Reserved memory
217 size_t reserved_size() const;
218 // Actually committed OS memory
219 size_t actual_committed_size() const;
220 // Memory used/expanded in this virtual space
221 size_t committed_size() const;
222 // Memory left to use/expand in this virtual space
223 size_t uncommitted_size() const;
224
225 bool contains(const void* p) const;
226
227 // Operations
228 // returns true on success, false otherwise
229 bool expand_by(size_t bytes, bool pre_touch = false);
230 void shrink_by(size_t bytes);
231 void release();
232
233 void check_for_contiguity() PRODUCT_RETURN;
234
235 // Debugging
236 void print_on(outputStream* out) PRODUCT_RETURN;
237 void print();
238 };
239
240 #endif // SHARE_MEMORY_VIRTUALSPACE_HPP