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