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
21 * questions.
22 *
23 */
24
25#ifndef SHARE_MEMORY_VIRTUALSPACE_HPP
26#define SHARE_MEMORY_VIRTUALSPACE_HPP
27
28#include "utilities/globalDefinitions.hpp"
29
30class outputStream;
31
32// ReservedSpace is a data structure for reserving a contiguous address range.
33
34class ReservedSpace {
35 friend class VMStructs;
36 protected:
37 char* _base;
38 size_t _size;
39 size_t _noaccess_prefix;
40 size_t _alignment;
41 bool _special;
42 int _fd_for_heap;
43 private:
44 bool _executable;
45
46 // ReservedSpace
47 ReservedSpace(char* base, size_t size, size_t alignment, bool special,
48 bool executable);
49 protected:
50 void initialize(size_t size, size_t alignment, bool large,
51 char* requested_address,
52 bool executable);
53
54 public:
55 // Constructor
56 ReservedSpace();
57 // Initialize the reserved space with the given size. If preferred_page_size
58 // is set, use this as minimum page size/alignment. This may waste some space
59 // if the given size is not aligned to that value, as the reservation will be
60 // aligned up to the final alignment in this case.
61 ReservedSpace(size_t size, size_t preferred_page_size = 0);
62 ReservedSpace(size_t size, size_t alignment, bool large,
63 char* requested_address = NULL);
64 ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
65
66 // Accessors
67 char* base() const { return _base; }
68 size_t size() const { return _size; }
69 char* end() const { return _base + _size; }
70 size_t alignment() const { return _alignment; }
71 bool special() const { return _special; }
72 bool executable() const { return _executable; }
73 size_t noaccess_prefix() const { return _noaccess_prefix; }
74 bool is_reserved() const { return _base != NULL; }
75 void release();
76
77 // Splitting
78 ReservedSpace first_part(size_t partition_size, size_t alignment,
79 bool split = false, bool realloc = true);
80 ReservedSpace last_part (size_t partition_size, size_t alignment);
81
82 // These simply call the above using the default alignment.
83 inline ReservedSpace first_part(size_t partition_size,
84 bool split = false, bool realloc = true);
85 inline ReservedSpace last_part (size_t partition_size);
86
87 // Alignment
88 static size_t page_align_size_up(size_t size);
89 static size_t page_align_size_down(size_t size);
90 static size_t allocation_align_size_up(size_t size);
91 bool contains(const void* p) const {
92 return (base() <= ((char*)p)) && (((char*)p) < (base() + size()));
93 }
94};
95
96ReservedSpace
97ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
98{
99 return first_part(partition_size, alignment(), split, realloc);
100}
101
102ReservedSpace ReservedSpace::last_part(size_t partition_size)
103{
104 return last_part(partition_size, alignment());
105}
106
107// Class encapsulating behavior specific of memory space reserved for Java heap.
108class ReservedHeapSpace : public ReservedSpace {
109 private:
110 void try_reserve_heap(size_t size, size_t alignment, bool large,
111 char *requested_address);
112 void try_reserve_range(char *highest_start, char *lowest_start,
113 size_t attach_point_alignment, char *aligned_HBMA,
114 char *upper_bound, size_t size, size_t alignment, bool large);
115 void initialize_compressed_heap(const size_t size, size_t alignment, bool large);
116 // Create protection page at the beginning of the space.
117 void establish_noaccess_prefix();
118 public:
119 // Constructor. Tries to find a heap that is good for compressed oops.
120 // heap_allocation_directory is the path to the backing memory for Java heap. When set, Java heap will be allocated
121 // on the device which is managed by the file system where the directory resides.
122 ReservedHeapSpace(size_t size, size_t forced_base_alignment, bool large, const char* heap_allocation_directory = NULL);
123 // Returns the base to be used for compression, i.e. so that null can be
124 // encoded safely and implicit null checks can work.
125 char *compressed_oop_base() { return _base - _noaccess_prefix; }
126};
127
128// Class encapsulating behavior specific memory space for Code
129class ReservedCodeSpace : public ReservedSpace {
130 public:
131 // Constructor
132 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
133};
134
135// VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
136
137class VirtualSpace {
138 friend class VMStructs;
139 private:
140 // Reserved area
141 char* _low_boundary;
142 char* _high_boundary;
143
144 // Committed area
145 char* _low;
146 char* _high;
147
148 // The entire space has been committed and pinned in memory, no
149 // os::commit_memory() or os::uncommit_memory().
150 bool _special;
151
152 // Need to know if commit should be executable.
153 bool _executable;
154
155 // MPSS Support
156 // Each virtualspace region has a lower, middle, and upper region.
157 // Each region has an end boundary and a high pointer which is the
158 // high water mark for the last allocated byte.
159 // The lower and upper unaligned to LargePageSizeInBytes uses default page.
160 // size. The middle region uses large page size.
161 char* _lower_high;
162 char* _middle_high;
163 char* _upper_high;
164
165 char* _lower_high_boundary;
166 char* _middle_high_boundary;
167 char* _upper_high_boundary;
168
169 size_t _lower_alignment;
170 size_t _middle_alignment;
171 size_t _upper_alignment;
172
173 // MPSS Accessors
174 char* lower_high() const { return _lower_high; }
175 char* middle_high() const { return _middle_high; }
176 char* upper_high() const { return _upper_high; }
177
178 char* lower_high_boundary() const { return _lower_high_boundary; }
179 char* middle_high_boundary() const { return _middle_high_boundary; }
180 char* upper_high_boundary() const { return _upper_high_boundary; }
181
182 size_t lower_alignment() const { return _lower_alignment; }
183 size_t middle_alignment() const { return _middle_alignment; }
184 size_t upper_alignment() const { return _upper_alignment; }
185
186 public:
187 // Committed area
188 char* low() const { return _low; }
189 char* high() const { return _high; }
190
191 // Reserved area
192 char* low_boundary() const { return _low_boundary; }
193 char* high_boundary() const { return _high_boundary; }
194
195#if INCLUDE_AOT
196 // Set boundaries for code section in AOT library.
197 void set_low_boundary(char *p) { _low_boundary = p; }
198 void set_high_boundary(char *p) { _high_boundary = p; }
199 void set_low(char *p) { _low = p; }
200 void set_high(char *p) { _high = p; }
201#endif
202
203 bool special() const { return _special; }
204
205 public:
206 // Initialization
207 VirtualSpace();
208 bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity);
209 bool initialize(ReservedSpace rs, size_t committed_byte_size);
210
211 // Destruction
212 ~VirtualSpace();
213
214 // Reserved memory
215 size_t reserved_size() const;
216 // Actually committed OS memory
217 size_t actual_committed_size() const;
218 // Memory used/expanded in this virtual space
219 size_t committed_size() const;
220 // Memory left to use/expand in this virtual space
221 size_t uncommitted_size() const;
222
223 bool contains(const void* p) const;
224
225 // Operations
226 // returns true on success, false otherwise
227 bool expand_by(size_t bytes, bool pre_touch = false);
228 void shrink_by(size_t bytes);
229 void release();
230
231 void check_for_contiguity() PRODUCT_RETURN;
232
233 // Debugging
234 void print_on(outputStream* out) PRODUCT_RETURN;
235 void print();
236};
237
238#endif // SHARE_MEMORY_VIRTUALSPACE_HPP
239