1 /* 2 * Copyright (c) 1997, 2017, 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 "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 preferred_page_size 55 // is set, use this as minimum page size/alignment. This may waste some space 56 // if the given size is not aligned to that value, as the reservation will be 57 // aligned up to the final alignment in this case. 58 ReservedSpace(size_t size, size_t preferred_page_size = 0); 59 ReservedSpace(size_t size, size_t alignment, bool large, 60 char* requested_address = NULL); 61 ReservedSpace(size_t size, size_t alignment, bool large, bool executable); 62 63 // Accessors 64 char* base() const { return _base; } 65 size_t size() const { return _size; } 66 char* end() const { return _base + _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 bool contains(const void* p) const { 90 return (base() <= ((char*)p)) && (((char*)p) < (base() + size())); 91 } 92 }; 93 94 ReservedSpace 95 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc) 96 { 97 return first_part(partition_size, alignment(), split, realloc); 98 } 99 100 ReservedSpace ReservedSpace::last_part(size_t partition_size) 101 { 102 return last_part(partition_size, alignment()); 103 } 104 105 // Class encapsulating behavior specific of memory space reserved for Java heap. 106 class ReservedHeapSpace : public ReservedSpace { 107 private: 108 void try_reserve_heap(size_t size, size_t alignment, bool large, 109 char *requested_address); 110 void try_reserve_range(char *highest_start, char *lowest_start, 111 size_t attach_point_alignment, char *aligned_HBMA, 112 char *upper_bound, size_t size, size_t alignment, bool large); 113 void initialize_compressed_heap(const size_t size, size_t alignment, bool large); 114 // Create protection page at the beginning of the space. 115 void establish_noaccess_prefix(); 116 public: 117 // Constructor. Tries to find a heap that is good for compressed oops. 118 ReservedHeapSpace(size_t size, size_t forced_base_alignment, bool large); 119 // Returns the base to be used for compression, i.e. so that null can be 120 // encoded safely and implicit null checks can work. 121 char *compressed_oop_base() { return _base - _noaccess_prefix; } 122 }; 123 124 // Class encapsulating behavior specific memory space for Code 125 class ReservedCodeSpace : public ReservedSpace { 126 public: 127 // Constructor 128 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large); 129 }; 130 131 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks. 132 133 class VirtualSpace VALUE_OBJ_CLASS_SPEC { 134 friend class VMStructs; 135 private: 136 // Reserved area 137 char* _low_boundary; 138 char* _high_boundary; 139 140 // Committed area 141 char* _low; 142 char* _high; 143 144 // The entire space has been committed and pinned in memory, no 145 // os::commit_memory() or os::uncommit_memory(). 146 bool _special; 147 148 // Need to know if commit should be executable. 149 bool _executable; 150 151 // MPSS Support 152 // Each virtualspace region has a lower, middle, and upper region. 153 // Each region has an end boundary and a high pointer which is the 154 // high water mark for the last allocated byte. 155 // The lower and upper unaligned to LargePageSizeInBytes uses default page. 156 // size. The middle region uses large page size. 157 char* _lower_high; 158 char* _middle_high; 159 char* _upper_high; 160 161 char* _lower_high_boundary; 162 char* _middle_high_boundary; 163 char* _upper_high_boundary; 164 165 size_t _lower_alignment; 166 size_t _middle_alignment; 167 size_t _upper_alignment; 168 169 // MPSS Accessors 170 char* lower_high() const { return _lower_high; } 171 char* middle_high() const { return _middle_high; } 172 char* upper_high() const { return _upper_high; } 173 174 char* lower_high_boundary() const { return _lower_high_boundary; } 175 char* middle_high_boundary() const { return _middle_high_boundary; } 176 char* upper_high_boundary() const { return _upper_high_boundary; } 177 178 size_t lower_alignment() const { return _lower_alignment; } 179 size_t middle_alignment() const { return _middle_alignment; } 180 size_t upper_alignment() const { return _upper_alignment; } 181 182 public: 183 // Committed area 184 char* low() const { return _low; } 185 char* high() const { return _high; } 186 187 // Reserved area 188 char* low_boundary() const { return _low_boundary; } 189 char* high_boundary() const { return _high_boundary; } 190 191 #if INCLUDE_AOT 192 // Set boundaries for code section in AOT library. 193 void set_low_boundary(char *p) { _low_boundary = p; } 194 void set_high_boundary(char *p) { _high_boundary = p; } 195 void set_low(char *p) { _low = p; } 196 void set_high(char *p) { _high = p; } 197 #endif 198 199 bool special() const { return _special; } 200 201 public: 202 // Initialization 203 VirtualSpace(); 204 bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity); 205 bool initialize(ReservedSpace rs, size_t committed_byte_size); 206 207 // Destruction 208 ~VirtualSpace(); 209 210 // Reserved memory 211 size_t reserved_size() const; 212 // Actually committed OS memory 213 size_t actual_committed_size() const; 214 // Memory used/expanded in this virtual space 215 size_t committed_size() const; 216 // Memory left to use/expand in this virtual space 217 size_t uncommitted_size() const; 218 219 bool contains(const void* p) const; 220 221 // Operations 222 // returns true on success, false otherwise 223 bool expand_by(size_t bytes, bool pre_touch = false); 224 void shrink_by(size_t bytes); 225 void release(); 226 227 void check_for_contiguity() PRODUCT_RETURN; 228 229 // Debugging 230 void print_on(outputStream* out) PRODUCT_RETURN; 231 void print(); 232 }; 233 234 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP