1 /* 2 * Copyright (c) 1997, 2018, 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_VM_RUNTIME_VIRTUALSPACE_HPP 26 #define SHARE_VM_RUNTIME_VIRTUALSPACE_HPP 27 28 #include "utilities/globalDefinitions.hpp" 29 30 // ReservedSpace is a data structure for reserving a contiguous address range. 31 32 class ReservedSpace { 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 int _fd_for_heap; 41 private: 42 bool _executable; 43 44 // ReservedSpace 45 ReservedSpace(char* base, size_t size, size_t alignment, bool special, 46 bool executable); 47 protected: 48 void initialize(size_t size, size_t alignment, bool large, 49 char* requested_address, 50 bool executable); 51 52 public: 53 // Constructor 54 ReservedSpace(); 55 // Initialize the reserved space with the given size. If preferred_page_size 56 // is set, use this as minimum page size/alignment. This may waste some space 57 // if the given size is not aligned to that value, as the reservation will be 58 // aligned up to the final alignment in this case. 59 ReservedSpace(size_t size, size_t preferred_page_size = 0); 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 char* end() const { return _base + _size; } 68 size_t alignment() const { return _alignment; } 69 bool special() const { return _special; } 70 bool executable() const { return _executable; } 71 size_t noaccess_prefix() const { return _noaccess_prefix; } 72 bool is_reserved() const { return _base != NULL; } 73 void release(); 74 75 // Splitting 76 ReservedSpace first_part(size_t partition_size, size_t alignment, 77 bool split = false, bool realloc = true); 78 ReservedSpace last_part (size_t partition_size, size_t alignment); 79 80 // These simply call the above using the default alignment. 81 inline ReservedSpace first_part(size_t partition_size, 82 bool split = false, bool realloc = true); 83 inline ReservedSpace last_part (size_t partition_size); 84 85 // Alignment 86 static size_t page_align_size_up(size_t size); 87 static size_t page_align_size_down(size_t size); 88 static size_t allocation_align_size_up(size_t size); 89 static size_t allocation_align_size_down(size_t size); 90 bool contains(const void* p) const { 91 return (base() <= ((char*)p)) && (((char*)p) < (base() + size())); 92 } 93 }; 94 95 ReservedSpace 96 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc) 97 { 98 return first_part(partition_size, alignment(), split, realloc); 99 } 100 101 ReservedSpace ReservedSpace::last_part(size_t partition_size) 102 { 103 return last_part(partition_size, alignment()); 104 } 105 106 // Class encapsulating behavior specific of memory space reserved for Java heap. 107 class ReservedHeapSpace : public ReservedSpace { 108 private: 109 void try_reserve_heap(size_t size, size_t alignment, bool large, 110 char *requested_address); 111 void try_reserve_range(char *highest_start, char *lowest_start, 112 size_t attach_point_alignment, char *aligned_HBMA, 113 char *upper_bound, size_t size, size_t alignment, bool large); 114 void initialize_compressed_heap(const size_t size, size_t alignment, bool large); 115 // Create protection page at the beginning of the space. 116 void establish_noaccess_prefix(); 117 public: 118 // Constructor. Tries to find a heap that is good for compressed oops. 119 // heap_allocation_directory is the path to the backing memory for Java heap. When set, Java heap will be allocated 120 // on the device which is managed by the file system where the directory resides. 121 ReservedHeapSpace(size_t size, size_t forced_base_alignment, bool large, const char* heap_allocation_directory = NULL); 122 // Returns the base to be used for compression, i.e. so that null can be 123 // encoded safely and implicit null checks can work. 124 char *compressed_oop_base() { return _base - _noaccess_prefix; } 125 }; 126 127 // Class encapsulating behavior specific memory space for Code 128 class ReservedCodeSpace : public ReservedSpace { 129 public: 130 // Constructor 131 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large); 132 }; 133 134 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks. 135 136 class VirtualSpace { 137 friend class VMStructs; 138 private: 139 // Reserved area 140 char* _low_boundary; 141 char* _high_boundary; 142 143 // Committed area 144 char* _low; 145 char* _high; 146 147 // The entire space has been committed and pinned in memory, no 148 // os::commit_memory() or os::uncommit_memory(). 149 bool _special; 150 151 // Need to know if commit should be executable. 152 bool _executable; 153 154 // MPSS Support 155 // Each virtualspace region has a lower, middle, and upper region. 156 // Each region has an end boundary and a high pointer which is the 157 // high water mark for the last allocated byte. 158 // The lower and upper unaligned to LargePageSizeInBytes uses default page. 159 // size. The middle region uses large page size. 160 char* _lower_high; 161 char* _middle_high; 162 char* _upper_high; 163 164 char* _lower_high_boundary; 165 char* _middle_high_boundary; 166 char* _upper_high_boundary; 167 168 size_t _lower_alignment; 169 size_t _middle_alignment; 170 size_t _upper_alignment; 171 172 // MPSS Accessors 173 char* lower_high() const { return _lower_high; } 174 char* middle_high() const { return _middle_high; } 175 char* upper_high() const { return _upper_high; } 176 177 char* lower_high_boundary() const { return _lower_high_boundary; } 178 char* middle_high_boundary() const { return _middle_high_boundary; } 179 char* upper_high_boundary() const { return _upper_high_boundary; } 180 181 size_t lower_alignment() const { return _lower_alignment; } 182 size_t middle_alignment() const { return _middle_alignment; } 183 size_t upper_alignment() const { return _upper_alignment; } 184 185 public: 186 // Committed area 187 char* low() const { return _low; } 188 char* high() const { return _high; } 189 190 // Reserved area 191 char* low_boundary() const { return _low_boundary; } 192 char* high_boundary() const { return _high_boundary; } 193 194 #if INCLUDE_AOT 195 // Set boundaries for code section in AOT library. 196 void set_low_boundary(char *p) { _low_boundary = p; } 197 void set_high_boundary(char *p) { _high_boundary = p; } 198 void set_low(char *p) { _low = p; } 199 void set_high(char *p) { _high = p; } 200 #endif 201 202 bool special() const { return _special; } 203 204 public: 205 // Initialization 206 VirtualSpace(); 207 bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity); 208 bool initialize(ReservedSpace rs, size_t committed_byte_size); 209 210 // Destruction 211 ~VirtualSpace(); 212 213 // Reserved memory 214 size_t reserved_size() const; 215 // Actually committed OS memory 216 size_t actual_committed_size() const; 217 // Memory used/expanded in this virtual space 218 size_t committed_size() const; 219 // Memory left to use/expand in this virtual space 220 size_t uncommitted_size() const; 221 222 bool contains(const void* p) const; 223 224 // Operations 225 // returns true on success, false otherwise 226 bool expand_by(size_t bytes, bool pre_touch = false); 227 void shrink_by(size_t bytes); 228 void release(); 229 230 void check_for_contiguity() PRODUCT_RETURN; 231 232 // Debugging 233 void print_on(outputStream* out) PRODUCT_RETURN; 234 void print(); 235 }; 236 237 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP