1 /* 2 * Copyright (c) 2003, 2018, 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_GC_PARALLEL_PSVIRTUALSPACE_HPP 26 #define SHARE_VM_GC_PARALLEL_PSVIRTUALSPACE_HPP 27 28 #include "memory/allocation.hpp" 29 #include "memory/virtualspace.hpp" 30 31 // VirtualSpace for the parallel scavenge collector. 32 // 33 // VirtualSpace is data structure for committing a previously reserved address 34 // range in smaller chunks. 35 36 class PSVirtualSpace : public CHeapObj<mtGC> { 37 friend class VMStructs; 38 protected: 39 // The space is committed/uncommitted in chunks of size _alignment. The 40 // ReservedSpace passed to initialize() must be aligned to this value. 41 const size_t _alignment; 42 43 // Reserved area 44 char* _reserved_low_addr; 45 char* _reserved_high_addr; 46 47 // Committed area 48 char* _committed_low_addr; 49 char* _committed_high_addr; 50 51 // The entire space has been committed and pinned in memory, no 52 // os::commit_memory() or os::uncommit_memory(). 53 bool _special; 54 55 // Convenience wrapper. 56 inline static size_t pointer_delta(const char* left, const char* right); 57 58 public: 59 PSVirtualSpace(ReservedSpace rs, size_t alignment); 60 PSVirtualSpace(ReservedSpace rs); 61 62 ~PSVirtualSpace(); 63 64 // Eventually all instances should be created with the above 1- or 2-arg 65 // constructors. Then the 1st constructor below should become protected and 66 // the 2nd ctor and initialize() removed. 67 PSVirtualSpace(size_t alignment): _alignment(alignment) { } 68 PSVirtualSpace(); 69 bool initialize(ReservedSpace rs, size_t commit_size); 70 71 bool contains(void* p) const; 72 73 // Accessors (all sizes are bytes). 74 size_t alignment() const { return _alignment; } 75 char* reserved_low_addr() const { return _reserved_low_addr; } 76 char* reserved_high_addr() const { return _reserved_high_addr; } 77 char* committed_low_addr() const { return _committed_low_addr; } 78 char* committed_high_addr() const { return _committed_high_addr; } 79 bool special() const { return _special; } 80 81 inline size_t committed_size() const; 82 inline size_t reserved_size() const; 83 inline size_t uncommitted_size() const; 84 85 // Operations. 86 inline void set_reserved(char* low_addr, char* high_addr, bool special); 87 inline void set_reserved(ReservedSpace rs); 88 inline void set_committed(char* low_addr, char* high_addr); 89 virtual bool expand_by(size_t bytes); 90 virtual bool shrink_by(size_t bytes); 91 virtual size_t expand_into(PSVirtualSpace* space, size_t bytes); 92 void release(); 93 94 // NVDIMM versions to manage expansion/shrinking 95 bool expand_by(size_t bytes, int fd); 96 size_t expand_into(PSVirtualSpace* space, size_t bytes, int fd); 97 98 #ifndef PRODUCT 99 // Debugging 100 static bool is_aligned(size_t val, size_t align); 101 bool is_aligned(size_t val) const; 102 bool is_aligned(char* val) const; 103 void verify() const; 104 virtual bool grows_up() const { return true; } 105 bool grows_down() const { return !grows_up(); } 106 107 // Helper class to verify a space when entering/leaving a block. 108 class PSVirtualSpaceVerifier: public StackObj { 109 private: 110 const PSVirtualSpace* const _space; 111 public: 112 PSVirtualSpaceVerifier(PSVirtualSpace* space): _space(space) { 113 _space->verify(); 114 } 115 ~PSVirtualSpaceVerifier() { _space->verify(); } 116 }; 117 #endif 118 119 virtual void print_space_boundaries_on(outputStream* st) const; 120 121 // Included for compatibility with the original VirtualSpace. 122 public: 123 // Committed area 124 char* low() const { return committed_low_addr(); } 125 char* high() const { return committed_high_addr(); } 126 127 // Reserved area 128 char* low_boundary() const { return reserved_low_addr(); } 129 char* high_boundary() const { return reserved_high_addr(); } 130 }; 131 132 // A virtual space that grows from high addresses to low addresses. 133 class PSVirtualSpaceHighToLow : public PSVirtualSpace { 134 friend class VMStructs; 135 public: 136 PSVirtualSpaceHighToLow(ReservedSpace rs, size_t alignment); 137 PSVirtualSpaceHighToLow(ReservedSpace rs); 138 139 virtual bool expand_by(size_t bytes); 140 virtual bool shrink_by(size_t bytes); 141 virtual size_t expand_into(PSVirtualSpace* space, size_t bytes); 142 143 virtual void print_space_boundaries_on(outputStream* st) const; 144 145 #ifndef PRODUCT 146 // Debugging 147 virtual bool grows_up() const { return false; } 148 #endif 149 }; 150 151 // 152 // PSVirtualSpace inlines. 153 // 154 inline size_t 155 PSVirtualSpace::pointer_delta(const char* left, const char* right) { 156 return ::pointer_delta((void *)left, (void*)right, sizeof(char)); 157 } 158 159 inline size_t PSVirtualSpace::committed_size() const { 160 return pointer_delta(committed_high_addr(), committed_low_addr()); 161 } 162 163 inline size_t PSVirtualSpace::reserved_size() const { 164 return pointer_delta(reserved_high_addr(), reserved_low_addr()); 165 } 166 167 inline size_t PSVirtualSpace::uncommitted_size() const { 168 return reserved_size() - committed_size(); 169 } 170 171 inline void PSVirtualSpace::set_reserved(char* low_addr, char* high_addr, bool special) { 172 _reserved_low_addr = low_addr; 173 _reserved_high_addr = high_addr; 174 _special = special; 175 } 176 177 inline void PSVirtualSpace::set_reserved(ReservedSpace rs) { 178 set_reserved(rs.base(), rs.base() + rs.size(), rs.special()); 179 } 180 181 inline void PSVirtualSpace::set_committed(char* low_addr, char* high_addr) { 182 _committed_low_addr = low_addr; 183 _committed_high_addr = high_addr; 184 } 185 186 #endif // SHARE_VM_GC_PARALLEL_PSVIRTUALSPACE_HPP