1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/src/share/vm/memory/memRegion.hpp Wed Apr 27 01:25:04 2016 +0800 1.3 @@ -0,0 +1,127 @@ 1.4 +/* 1.5 + * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. 1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 1.7 + * 1.8 + * This code is free software; you can redistribute it and/or modify it 1.9 + * under the terms of the GNU General Public License version 2 only, as 1.10 + * published by the Free Software Foundation. 1.11 + * 1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT 1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 1.15 + * version 2 for more details (a copy is included in the LICENSE file that 1.16 + * accompanied this code). 1.17 + * 1.18 + * You should have received a copy of the GNU General Public License version 1.19 + * 2 along with this work; if not, write to the Free Software Foundation, 1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 1.21 + * 1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 1.23 + * or visit www.oracle.com if you need additional information or have any 1.24 + * questions. 1.25 + * 1.26 + */ 1.27 + 1.28 +#ifndef SHARE_VM_MEMORY_MEMREGION_HPP 1.29 +#define SHARE_VM_MEMORY_MEMREGION_HPP 1.30 + 1.31 +#include "memory/allocation.hpp" 1.32 +#include "utilities/debug.hpp" 1.33 +#include "utilities/globalDefinitions.hpp" 1.34 + 1.35 +// A very simple data structure representing a contigous region 1.36 +// region of address space. 1.37 + 1.38 +// Note that MemRegions are passed by value, not by reference. 1.39 +// The intent is that they remain very small and contain no 1.40 +// objects. _ValueObj should never be allocated in heap but we do 1.41 +// create MemRegions (in CardTableModRefBS) in heap so operator 1.42 +// new and operator new [] added for this special case. 1.43 + 1.44 +class MetaWord; 1.45 + 1.46 +class MemRegion VALUE_OBJ_CLASS_SPEC { 1.47 + friend class VMStructs; 1.48 +private: 1.49 + HeapWord* _start; 1.50 + size_t _word_size; 1.51 + 1.52 +public: 1.53 + MemRegion() : _start(NULL), _word_size(0) {}; 1.54 + MemRegion(HeapWord* start, size_t word_size) : 1.55 + _start(start), _word_size(word_size) {}; 1.56 + MemRegion(HeapWord* start, HeapWord* end) : 1.57 + _start(start), _word_size(pointer_delta(end, start)) { 1.58 + assert(end >= start, "incorrect constructor arguments"); 1.59 + } 1.60 + MemRegion(MetaWord* start, MetaWord* end) : 1.61 + _start((HeapWord*)start), _word_size(pointer_delta(end, start)) { 1.62 + assert(end >= start, "incorrect constructor arguments"); 1.63 + } 1.64 + 1.65 + MemRegion(const MemRegion& mr): _start(mr._start), _word_size(mr._word_size) {} 1.66 + 1.67 + MemRegion intersection(const MemRegion mr2) const; 1.68 + // regions must overlap or be adjacent 1.69 + MemRegion _union(const MemRegion mr2) const; 1.70 + // minus will fail a guarantee if mr2 is interior to this, 1.71 + // since there's no way to return 2 disjoint regions. 1.72 + MemRegion minus(const MemRegion mr2) const; 1.73 + 1.74 + HeapWord* start() const { return _start; } 1.75 + HeapWord* end() const { return _start + _word_size; } 1.76 + HeapWord* last() const { return _start + _word_size - 1; } 1.77 + 1.78 + void set_start(HeapWord* start) { _start = start; } 1.79 + void set_end(HeapWord* end) { _word_size = pointer_delta(end, _start); } 1.80 + void set_word_size(size_t word_size) { 1.81 + _word_size = word_size; 1.82 + } 1.83 + 1.84 + bool contains(const MemRegion mr2) const { 1.85 + return _start <= mr2._start && end() >= mr2.end(); 1.86 + } 1.87 + bool contains(const void* addr) const { 1.88 + return addr >= (void*)_start && addr < (void*)end(); 1.89 + } 1.90 + bool equals(const MemRegion mr2) const { 1.91 + // first disjunct since we do not have a canonical empty set 1.92 + return ((is_empty() && mr2.is_empty()) || 1.93 + (start() == mr2.start() && end() == mr2.end())); 1.94 + } 1.95 + 1.96 + size_t byte_size() const { return _word_size * sizeof(HeapWord); } 1.97 + size_t word_size() const { return _word_size; } 1.98 + 1.99 + bool is_empty() const { return word_size() == 0; } 1.100 + void* operator new(size_t size) throw(); 1.101 + void* operator new [](size_t size) throw(); 1.102 + void operator delete(void* p); 1.103 + void operator delete [](void* p); 1.104 +}; 1.105 + 1.106 +// For iteration over MemRegion's. 1.107 + 1.108 +class MemRegionClosure : public StackObj { 1.109 +public: 1.110 + virtual void do_MemRegion(MemRegion mr) = 0; 1.111 +}; 1.112 + 1.113 +// A ResourceObj version of MemRegionClosure 1.114 + 1.115 +class MemRegionClosureRO: public MemRegionClosure { 1.116 +public: 1.117 + void* operator new(size_t size, ResourceObj::allocation_type type, MEMFLAGS flags) throw() { 1.118 + return ResourceObj::operator new(size, type, flags); 1.119 + } 1.120 + void* operator new(size_t size, Arena *arena) throw() { 1.121 + return ResourceObj::operator new(size, arena); 1.122 + } 1.123 + void* operator new(size_t size) throw() { 1.124 + return ResourceObj::operator new(size); 1.125 + } 1.126 + 1.127 + void operator delete(void* p) {} // nothing to do 1.128 +}; 1.129 + 1.130 +#endif // SHARE_VM_MEMORY_MEMREGION_HPP