1 /* 2 * Copyright (c) 1997, 2020, 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 "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; 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 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 // This splits the space into two spaces, the first part of which will be returned. 79 // If split==true, the resulting two spaces can be released independently from each other. 80 // This may cause the original space to loose its content. 81 // They also will be tracked individually by NMT and can be tagged with different flags. 82 // Note that this may cause the original space to loose its content. 83 // If split==false, the resulting space will be just a hotspot-internal representation 84 // of a sub section of the underlying mapping. 85 ReservedSpace first_part(size_t partition_size, size_t alignment, bool split = false); 86 ReservedSpace last_part (size_t partition_size, size_t alignment); 87 88 // These simply call the above using the default alignment. 89 inline ReservedSpace first_part(size_t partition_size, bool split = false); 90 inline ReservedSpace last_part (size_t partition_size); 91 92 // Alignment 93 static size_t page_align_size_up(size_t size); 94 static size_t page_align_size_down(size_t size); 95 static size_t allocation_align_size_up(size_t size); 96 bool contains(const void* p) const { 97 return (base() <= ((char*)p)) && (((char*)p) < (base() + size())); 98 } 99 }; 100 101 ReservedSpace 102 ReservedSpace::first_part(size_t partition_size, bool split) 103 { 104 return first_part(partition_size, alignment(), split); 105 } 106 107 ReservedSpace ReservedSpace::last_part(size_t partition_size) 108 { 109 return last_part(partition_size, alignment()); 110 } 111 112 // Class encapsulating behavior specific of memory space reserved for Java heap. 113 class ReservedHeapSpace : public ReservedSpace { 114 private: 115 void try_reserve_heap(size_t size, size_t alignment, bool large, 116 char *requested_address); 117 void try_reserve_range(char *highest_start, char *lowest_start, 118 size_t attach_point_alignment, char *aligned_HBMA, 119 char *upper_bound, size_t size, size_t alignment, bool large); 120 void initialize_compressed_heap(const size_t size, size_t alignment, bool large); 121 // Create protection page at the beginning of the space. 122 void establish_noaccess_prefix(); 123 public: 124 // Constructor. Tries to find a heap that is good for compressed oops. 125 // heap_allocation_directory is the path to the backing memory for Java heap. When set, Java heap will be allocated 126 // on the device which is managed by the file system where the directory resides. 127 ReservedHeapSpace(size_t size, size_t forced_base_alignment, bool large, const char* heap_allocation_directory = NULL); 128 // Returns the base to be used for compression, i.e. so that null can be 129 // encoded safely and implicit null checks can work. 130 char *compressed_oop_base() const { return _base - _noaccess_prefix; } 131 MemRegion region() const; 132 }; 133 134 // Class encapsulating behavior specific memory space for Code 135 class ReservedCodeSpace : public ReservedSpace { 136 public: 137 // Constructor 138 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large); 139 }; 140 141 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks. 142 143 class VirtualSpace { 144 friend class VMStructs; 145 private: 146 // Reserved area 147 char* _low_boundary; 148 char* _high_boundary; 149 150 // Committed area 151 char* _low; 152 char* _high; 153 154 // The entire space has been committed and pinned in memory, no 155 // os::commit_memory() or os::uncommit_memory(). 156 bool _special; 157 158 // Need to know if commit should be executable. 159 bool _executable; 160 161 // MPSS Support 162 // Each virtualspace region has a lower, middle, and upper region. 163 // Each region has an end boundary and a high pointer which is the 164 // high water mark for the last allocated byte. 165 // The lower and upper unaligned to LargePageSizeInBytes uses default page. 166 // size. The middle region uses large page size. 167 char* _lower_high; 168 char* _middle_high; 169 char* _upper_high; 170 171 char* _lower_high_boundary; 172 char* _middle_high_boundary; 173 char* _upper_high_boundary; 174 175 size_t _lower_alignment; 176 size_t _middle_alignment; 177 size_t _upper_alignment; 178 179 // MPSS Accessors 180 char* lower_high() const { return _lower_high; } 181 char* middle_high() const { return _middle_high; } 182 char* upper_high() const { return _upper_high; } 183 184 char* lower_high_boundary() const { return _lower_high_boundary; } 185 char* middle_high_boundary() const { return _middle_high_boundary; } 186 char* upper_high_boundary() const { return _upper_high_boundary; } 187 188 size_t lower_alignment() const { return _lower_alignment; } 189 size_t middle_alignment() const { return _middle_alignment; } 190 size_t upper_alignment() const { return _upper_alignment; } 191 192 public: 193 // Committed area 194 char* low() const { return _low; } 195 char* high() const { return _high; } 196 197 // Reserved area 198 char* low_boundary() const { return _low_boundary; } 199 char* high_boundary() const { return _high_boundary; } 200 201 #if INCLUDE_AOT 202 // Set boundaries for code section in AOT library. 203 void set_low_boundary(char *p) { _low_boundary = p; } 204 void set_high_boundary(char *p) { _high_boundary = p; } 205 void set_low(char *p) { _low = p; } 206 void set_high(char *p) { _high = p; } 207 #endif 208 209 bool special() const { return _special; } 210 211 public: 212 // Initialization 213 VirtualSpace(); 214 bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity); 215 bool initialize(ReservedSpace rs, size_t committed_byte_size); 216 217 // Destruction 218 ~VirtualSpace(); 219 220 // Reserved memory 221 size_t reserved_size() const; 222 // Actually committed OS memory 223 size_t actual_committed_size() const; 224 // Memory used/expanded in this virtual space 225 size_t committed_size() const; 226 // Memory left to use/expand in this virtual space 227 size_t uncommitted_size() const; 228 229 bool contains(const void* p) const; 230 231 // Operations 232 // returns true on success, false otherwise 233 bool expand_by(size_t bytes, bool pre_touch = false); 234 void shrink_by(size_t bytes); 235 void release(); 236 237 void check_for_contiguity() PRODUCT_RETURN; 238 239 // Debugging 240 void print_on(outputStream* out) PRODUCT_RETURN; 241 void print(); 242 }; 243 244 #endif // SHARE_MEMORY_VIRTUALSPACE_HPP