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