Mercurial > hg > truffle
diff src/share/vm/memory/memRegion.hpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | c18cbe5936b8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/memory/memRegion.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,106 @@ +/* + * Copyright 2000-2004 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +// A very simple data structure representing a contigous region +// region of address space. + +// Note that MemRegions are passed by value, not by reference. +// The intent is that they remain very small and contain no +// objects. + +class MemRegion VALUE_OBJ_CLASS_SPEC { + friend class VMStructs; +private: + HeapWord* _start; + size_t _word_size; + +public: + MemRegion() : _start(NULL), _word_size(0) {}; + MemRegion(HeapWord* start, size_t word_size) : + _start(start), _word_size(word_size) {}; + MemRegion(HeapWord* start, HeapWord* end) : + _start(start), _word_size(pointer_delta(end, start)) { + assert(end >= start, "incorrect constructor arguments"); + } + + MemRegion(const MemRegion& mr): _start(mr._start), _word_size(mr._word_size) {} + + MemRegion intersection(const MemRegion mr2) const; + // regions must overlap or be adjacent + MemRegion _union(const MemRegion mr2) const; + // minus will fail a guarantee if mr2 is interior to this, + // since there's no way to return 2 disjoint regions. + MemRegion minus(const MemRegion mr2) const; + + HeapWord* start() const { return _start; } + HeapWord* end() const { return _start + _word_size; } + HeapWord* last() const { return _start + _word_size - 1; } + + void set_start(HeapWord* start) { _start = start; } + void set_end(HeapWord* end) { _word_size = pointer_delta(end, _start); } + void set_word_size(size_t word_size) { + _word_size = word_size; + } + + bool contains(const MemRegion mr2) const { + return _start <= mr2._start && end() >= mr2.end(); + } + bool contains(const void* addr) const { + return addr >= (void*)_start && addr < (void*)end(); + } + bool equals(const MemRegion mr2) const { + // first disjunct since we do not have a canonical empty set + return ((is_empty() && mr2.is_empty()) || + (start() == mr2.start() && end() == mr2.end())); + } + + size_t byte_size() const { return _word_size * sizeof(HeapWord); } + size_t word_size() const { return _word_size; } + + bool is_empty() const { return word_size() == 0; } +}; + +// For iteration over MemRegion's. + +class MemRegionClosure : public StackObj { +public: + virtual void do_MemRegion(MemRegion mr) = 0; +}; + +// A ResourceObj version of MemRegionClosure + +class MemRegionClosureRO: public MemRegionClosure { +public: + void* operator new(size_t size, ResourceObj::allocation_type type) { + return ResourceObj::operator new(size, type); + } + void* operator new(size_t size, Arena *arena) { + return ResourceObj::operator new(size, arena); + } + void* operator new(size_t size) { + return ResourceObj::operator new(size); + } + + void operator delete(void* p) {} // nothing to do +};