1 /* 2 * Copyright (c) 1997, 2015, 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 size_t alignment() const { return _alignment; } 67 bool special() const { return _special; } 68 bool executable() const { return _executable; } 69 size_t noaccess_prefix() const { return _noaccess_prefix; } 70 bool is_reserved() const { return _base != NULL; } 71 void release(); 72 73 // Splitting 74 ReservedSpace first_part(size_t partition_size, size_t alignment, 75 bool split = false, bool realloc = true); 76 ReservedSpace last_part (size_t partition_size, size_t alignment); 77 78 // These simply call the above using the default alignment. 79 inline ReservedSpace first_part(size_t partition_size, 80 bool split = false, bool realloc = true); 81 inline ReservedSpace last_part (size_t partition_size); 82 83 // Alignment 84 static size_t page_align_size_up(size_t size); 85 static size_t page_align_size_down(size_t size); 86 static size_t allocation_align_size_up(size_t size); 87 static size_t allocation_align_size_down(size_t size); 88 }; 89 90 ReservedSpace 91 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc) 92 { 93 return first_part(partition_size, alignment(), split, realloc); 94 } 95 96 ReservedSpace ReservedSpace::last_part(size_t partition_size) 97 { 98 return last_part(partition_size, alignment()); 99 } 100 101 // Class encapsulating behavior specific of memory space reserved for Java heap. 102 class ReservedHeapSpace : public ReservedSpace { 103 private: 104 void try_reserve_heap(size_t size, size_t alignment, bool large, 105 char *requested_address); 106 void try_reserve_range(char *highest_start, char *lowest_start, 107 size_t attach_point_alignment, char *aligned_HBMA, 108 char *upper_bound, size_t size, size_t alignment, bool large); 109 void initialize_compressed_heap(const size_t size, size_t alignment, bool large); 110 // Create protection page at the beginning of the space. 111 void establish_noaccess_prefix(); 112 public: 113 // Constructor. Tries to find a heap that is good for compressed oops. 114 ReservedHeapSpace(size_t size, size_t forced_base_alignment, bool large); 115 // Returns the base to be used for compression, i.e. so that null can be 116 // encoded safely and implicit null checks can work. 117 char *compressed_oop_base() { return _base - _noaccess_prefix; } 118 }; 119 120 // Class encapsulating behavior specific memory space for Code 121 class ReservedCodeSpace : public ReservedSpace { 122 public: 123 // Constructor 124 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large); 125 }; 126 127 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks. 128 129 class VirtualSpace VALUE_OBJ_CLASS_SPEC { 130 friend class VMStructs; 131 private: 132 // Reserved area 133 char* _low_boundary; 134 char* _high_boundary; 135 136 // Committed area 137 char* _low; 138 char* _high; 139 140 // The entire space has been committed and pinned in memory, no 141 // os::commit_memory() or os::uncommit_memory(). 142 bool _special; 143 144 // Need to know if commit should be executable. 145 bool _executable; 146 147 // MPSS Support 148 // Each virtualspace region has a lower, middle, and upper region. 149 // Each region has an end boundary and a high pointer which is the 150 // high water mark for the last allocated byte. 151 // The lower and upper unaligned to LargePageSizeInBytes uses default page. 152 // size. The middle region uses large page size. 153 char* _lower_high; 154 char* _middle_high; 155 char* _upper_high; 156 157 char* _lower_high_boundary; 158 char* _middle_high_boundary; 159 char* _upper_high_boundary; 160 161 size_t _lower_alignment; 162 size_t _middle_alignment; 163 size_t _upper_alignment; 164 165 // MPSS Accessors 166 char* lower_high() const { return _lower_high; } 167 char* middle_high() const { return _middle_high; } 168 char* upper_high() const { return _upper_high; } 169 170 char* lower_high_boundary() const { return _lower_high_boundary; } 171 char* middle_high_boundary() const { return _middle_high_boundary; } 172 char* upper_high_boundary() const { return _upper_high_boundary; } 173 174 size_t lower_alignment() const { return _lower_alignment; } 175 size_t middle_alignment() const { return _middle_alignment; } 176 size_t upper_alignment() const { return _upper_alignment; } 177 178 public: 179 // Committed area 180 char* low() const { return _low; } 181 char* high() const { return _high; } 182 183 // Reserved area 184 char* low_boundary() const { return _low_boundary; } 185 char* high_boundary() const { return _high_boundary; } 186 187 bool special() const { return _special; } 188 189 public: 190 // Initialization 191 VirtualSpace(); 192 bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity); 193 bool initialize(ReservedSpace rs, size_t committed_byte_size); 194 195 // Destruction 196 ~VirtualSpace(); 197 198 // Reserved memory 199 size_t reserved_size() const; 200 // Actually committed OS memory 201 size_t actual_committed_size() const; 202 // Memory used/expanded in this virtual space 203 size_t committed_size() const; 204 // Memory left to use/expand in this virtual space 205 size_t uncommitted_size() const; 206 207 bool contains(const void* p) const; 208 209 // Operations 210 // returns true on success, false otherwise 211 bool expand_by(size_t bytes, bool pre_touch = false); 212 void shrink_by(size_t bytes); 213 void release(); 214 215 void check_for_contiguity() PRODUCT_RETURN; 216 217 // Debugging 218 void print_on(outputStream* out) PRODUCT_RETURN; 219 void print(); 220 }; 221 222 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP