1 /* 2 * Copyright (c) 1997, 2012, 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 suffix_size, const size_t suffix_align, 83 char* requested_address, 84 const size_t noaccess_prefix = 0); 85 ReservedSpace(size_t size, size_t alignment, bool large, bool executable); 86 87 // Accessors 88 char* base() const { return _base; } 89 size_t size() const { return _size; } 90 size_t alignment() const { return _alignment; } 91 bool special() const { return _special; } 92 bool executable() const { return _executable; } 93 size_t noaccess_prefix() const { return _noaccess_prefix; } 94 bool is_reserved() const { return _base != NULL; } 95 void release(); 96 97 // Splitting 98 ReservedSpace first_part(size_t partition_size, size_t alignment, 99 bool split = false, bool realloc = true); 100 ReservedSpace last_part (size_t partition_size, size_t alignment); 101 102 // These simply call the above using the default alignment. 103 inline ReservedSpace first_part(size_t partition_size, 104 bool split = false, bool realloc = true); 105 inline ReservedSpace last_part (size_t partition_size); 106 107 // Alignment 108 static size_t page_align_size_up(size_t size); 109 static size_t page_align_size_down(size_t size); 110 static size_t allocation_align_size_up(size_t size); 111 static size_t allocation_align_size_down(size_t size); 112 }; 113 114 ReservedSpace 115 ReservedSpace::first_part(size_t partition_size, bool split, bool realloc) 116 { 117 return first_part(partition_size, alignment(), split, realloc); 118 } 119 120 ReservedSpace ReservedSpace::last_part(size_t partition_size) 121 { 122 return last_part(partition_size, alignment()); 123 } 124 125 // Class encapsulating behavior specific of memory space reserved for Java heap 126 class ReservedHeapSpace : public ReservedSpace { 127 public: 128 // Constructor 129 ReservedHeapSpace(size_t size, size_t forced_base_alignment, 130 bool large, char* requested_address); 131 ReservedHeapSpace(const size_t prefix_size, const size_t prefix_align, 132 char* requested_address); 133 }; 134 135 // Class encapsulating behavior specific memory space for Code 136 class ReservedCodeSpace : public ReservedSpace { 137 public: 138 // Constructor 139 ReservedCodeSpace(size_t r_size, size_t rs_align, bool large); 140 }; 141 142 // VirtualSpace is data structure for committing a previously reserved address range in smaller chunks. 143 144 class VirtualSpace VALUE_OBJ_CLASS_SPEC { 145 friend class VMStructs; 146 private: 147 // Reserved area 148 char* _low_boundary; 149 char* _high_boundary; 150 151 // Committed area 152 char* _low; 153 char* _high; 154 155 // The entire space has been committed and pinned in memory, no 156 // os::commit_memory() or os::uncommit_memory(). 157 bool _special; 158 159 // Need to know if commit should be executable. 160 bool _executable; 161 162 // MPSS Support 163 // Each virtualspace region has a lower, middle, and upper region. 164 // Each region has an end boundary and a high pointer which is the 165 // high water mark for the last allocated byte. 166 // The lower and upper unaligned to LargePageSizeInBytes uses default page. 167 // size. The middle region uses large page size. 168 char* _lower_high; 169 char* _middle_high; 170 char* _upper_high; 171 172 char* _lower_high_boundary; 173 char* _middle_high_boundary; 174 char* _upper_high_boundary; 175 176 size_t _lower_alignment; 177 size_t _middle_alignment; 178 size_t _upper_alignment; 179 180 // MPSS Accessors 181 char* lower_high() const { return _lower_high; } 182 char* middle_high() const { return _middle_high; } 183 char* upper_high() const { return _upper_high; } 184 185 char* lower_high_boundary() const { return _lower_high_boundary; } 186 char* middle_high_boundary() const { return _middle_high_boundary; } 187 char* upper_high_boundary() const { return _upper_high_boundary; } 188 189 size_t lower_alignment() const { return _lower_alignment; } 190 size_t middle_alignment() const { return _middle_alignment; } 191 size_t upper_alignment() const { return _upper_alignment; } 192 193 public: 194 // Committed area 195 char* low() const { return _low; } 196 char* high() const { return _high; } 197 198 // Reserved area 199 char* low_boundary() const { return _low_boundary; } 200 char* high_boundary() const { return _high_boundary; } 201 202 bool special() const { return _special; } 203 204 public: 205 // Initialization 206 VirtualSpace(); 207 bool initialize(ReservedSpace rs, size_t committed_byte_size); 208 209 // Destruction 210 ~VirtualSpace(); 211 212 // Testers (all sizes are byte sizes) 213 size_t committed_size() const; 214 size_t reserved_size() const; 215 size_t uncommitted_size() const; 216 bool contains(const void* p) const; 217 218 // Operations 219 // returns true on success, false otherwise 220 bool expand_by(size_t bytes, bool pre_touch = false); 221 void shrink_by(size_t bytes); 222 void release(); 223 224 void check_for_contiguity() PRODUCT_RETURN; 225 226 // Debugging 227 void print() PRODUCT_RETURN; 228 }; 229 230 #endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP