1 /* 2 * Copyright (c) 1997, 2010, 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 private: 35 char* _base; 36 size_t _size; 37 size_t _noaccess_prefix; 38 size_t _alignment; 39 bool _special; 40 bool _executable; 41 42 // ReservedSpace 43 ReservedSpace(char* base, size_t size, size_t alignment, bool special, 44 bool executable); 45 void initialize(size_t size, size_t alignment, bool large, 46 char* requested_address, 47 const size_t noaccess_prefix, 48 bool executable); 49 50 // Release parts of an already-reserved memory region [addr, addr + len) to 51 // get a new region that has "compound alignment." Return the start of the 52 // resulting region, or NULL on failure. 53 // 54 // The region is logically divided into a prefix and a suffix. The prefix 55 // starts at the result address, which is aligned to prefix_align. The suffix 56 // starts at result address + prefix_size, which is aligned to suffix_align. 57 // The total size of the result region is size prefix_size + suffix_size. 58 char* align_reserved_region(char* addr, const size_t len, 59 const size_t prefix_size, 60 const size_t prefix_align, 61 const size_t suffix_size, 62 const size_t suffix_align); 63 64 // Reserve memory, call align_reserved_region() to alignment it and return the 65 // result. 66 char* reserve_and_align(const size_t reserve_size, 67 const size_t prefix_size, 68 const size_t prefix_align, 69 const size_t suffix_size, 70 const size_t suffix_align); 71 72 protected: 73 // Create protection page at the beginning of the space. 74 void protect_noaccess_prefix(const size_t size); 75 76 public: 77 // Constructor 78 ReservedSpace(size_t size); 79 ReservedSpace(size_t size, size_t alignment, bool large, 80 char* requested_address = NULL, 81 const size_t noaccess_prefix = 0); 82 ReservedSpace(const size_t prefix_size, const size_t prefix_align, 83 const size_t suffix_size, const size_t suffix_align, 84 char* requested_address, 85 const size_t noaccess_prefix = 0); 86 ReservedSpace(size_t size, size_t alignment, bool large, bool executable); 87 88 // Accessors 89 char* base() const { return _base; } 90 size_t size() const { return _size; } 91 size_t alignment() const { return _alignment; } 92 bool special() const { return _special; } 93 bool executable() const { return _executable; } 94 size_t noaccess_prefix() const { return _noaccess_prefix; } 95 bool is_reserved() const { return _base != NULL; } 96 void release(); 97 98 // Splitting 99 ReservedSpace first_part(size_t partition_size, size_t alignment, 100 bool split = false, bool realloc = true); 101 ReservedSpace last_part (size_t partition_size, size_t alignment); 102 103 // These simply call the above using the default alignment. 104 inline ReservedSpace first_part(size_t partition_size, 105 bool split = false, bool realloc = true); 106 inline ReservedSpace last_part (size_t partition_size); 107 108 // Alignment 109 static size_t page_align_size_up(size_t size); 110 static size_t page_align_size_down(size_t size); 111 static size_t allocation_align_size_up(size_t size); 112 static size_t allocation_align_size_down(size_t size); 113 }; 114 115 ReservedSpace 116 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc) 117 { 118 return first_part(partition_size, alignment(), split, realloc); 119 } 120 121 ReservedSpace ReservedSpace::last_part(size_t partition_size) 122 { 123 return last_part(partition_size, alignment()); 124 } 125 126 // Class encapsulating behavior specific of memory space reserved for Java heap 127 class ReservedHeapSpace : public ReservedSpace { 128 public: 129 // Constructor 130 ReservedHeapSpace(size_t size, size_t forced_base_alignment, 131 bool large, char* requested_address); 132 ReservedHeapSpace(const size_t prefix_size, const size_t prefix_align, 133 const size_t suffix_size, const size_t suffix_align, 134 char* requested_address); 135 }; 136 137 // Class encapsulating behavior specific memory space for Code 138 class ReservedCodeSpace : public ReservedSpace { 139 public: 140 // Constructor 141 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large); 142 }; 143 144 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks. 145 146 class VirtualSpace VALUE_OBJ_CLASS_SPEC { 147 friend class VMStructs; 148 private: 149 // Reserved area 150 char* _low_boundary; 151 char* _high_boundary; 152 153 // Committed area 154 char* _low; 155 char* _high; 156 157 // The entire space has been committed and pinned in memory, no 158 // os::commit_memory() or os::uncommit_memory(). 159 bool _special; 160 161 // Need to know if commit should be executable. 162 bool _executable; 163 164 // MPSS Support 165 // Each virtualspace region has a lower, middle, and upper region. 166 // Each region has an end boundary and a high pointer which is the 167 // high water mark for the last allocated byte. 168 // The lower and upper unaligned to LargePageSizeInBytes uses default page. 169 // size. The middle region uses large page size. 170 char* _lower_high; 171 char* _middle_high; 172 char* _upper_high; 173 174 char* _lower_high_boundary; 175 char* _middle_high_boundary; 176 char* _upper_high_boundary; 177 178 size_t _lower_alignment; 179 size_t _middle_alignment; 180 size_t _upper_alignment; 181 182 // MPSS Accessors 183 char* lower_high() const { return _lower_high; } 184 char* middle_high() const { return _middle_high; } 185 char* upper_high() const { return _upper_high; } 186 187 char* lower_high_boundary() const { return _lower_high_boundary; } 188 char* middle_high_boundary() const { return _middle_high_boundary; } 189 char* upper_high_boundary() const { return _upper_high_boundary; } 190 191 size_t lower_alignment() const { return _lower_alignment; } 192 size_t middle_alignment() const { return _middle_alignment; } 193 size_t upper_alignment() const { return _upper_alignment; } 194 195 public: 196 // Committed area 197 char* low() const { return _low; } 198 char* high() const { return _high; } 199 200 // Reserved area 201 char* low_boundary() const { return _low_boundary; } 202 char* high_boundary() const { return _high_boundary; } 203 204 bool special() const { return _special; } 205 206 public: 207 // Initialization 208 VirtualSpace(); 209 bool initialize(ReservedSpace rs, size_t committed_byte_size); 210 211 // Destruction 212 ~VirtualSpace(); 213 214 // Testers (all sizes are byte sizes) 215 size_t committed_size() const; 216 size_t reserved_size() const; 217 size_t uncommitted_size() const; 218 bool contains(const void* p) const; 219 220 // Operations 221 // returns true on success, false otherwise 222 bool expand_by(size_t bytes, bool pre_touch = false); 223 void shrink_by(size_t bytes); 224 void release(); 225 226 void check_for_contiguity() PRODUCT_RETURN; 227 228 // Debugging 229 void print() PRODUCT_RETURN; 230 }; 231 232 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP