1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/memory/memRegion.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,106 @@
1.4 +/*
1.5 + * Copyright 2000-2004 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +// A very simple data structure representing a contigous region
1.29 +// region of address space.
1.30 +
1.31 +// Note that MemRegions are passed by value, not by reference.
1.32 +// The intent is that they remain very small and contain no
1.33 +// objects.
1.34 +
1.35 +class MemRegion VALUE_OBJ_CLASS_SPEC {
1.36 + friend class VMStructs;
1.37 +private:
1.38 + HeapWord* _start;
1.39 + size_t _word_size;
1.40 +
1.41 +public:
1.42 + MemRegion() : _start(NULL), _word_size(0) {};
1.43 + MemRegion(HeapWord* start, size_t word_size) :
1.44 + _start(start), _word_size(word_size) {};
1.45 + MemRegion(HeapWord* start, HeapWord* end) :
1.46 + _start(start), _word_size(pointer_delta(end, start)) {
1.47 + assert(end >= start, "incorrect constructor arguments");
1.48 + }
1.49 +
1.50 + MemRegion(const MemRegion& mr): _start(mr._start), _word_size(mr._word_size) {}
1.51 +
1.52 + MemRegion intersection(const MemRegion mr2) const;
1.53 + // regions must overlap or be adjacent
1.54 + MemRegion _union(const MemRegion mr2) const;
1.55 + // minus will fail a guarantee if mr2 is interior to this,
1.56 + // since there's no way to return 2 disjoint regions.
1.57 + MemRegion minus(const MemRegion mr2) const;
1.58 +
1.59 + HeapWord* start() const { return _start; }
1.60 + HeapWord* end() const { return _start + _word_size; }
1.61 + HeapWord* last() const { return _start + _word_size - 1; }
1.62 +
1.63 + void set_start(HeapWord* start) { _start = start; }
1.64 + void set_end(HeapWord* end) { _word_size = pointer_delta(end, _start); }
1.65 + void set_word_size(size_t word_size) {
1.66 + _word_size = word_size;
1.67 + }
1.68 +
1.69 + bool contains(const MemRegion mr2) const {
1.70 + return _start <= mr2._start && end() >= mr2.end();
1.71 + }
1.72 + bool contains(const void* addr) const {
1.73 + return addr >= (void*)_start && addr < (void*)end();
1.74 + }
1.75 + bool equals(const MemRegion mr2) const {
1.76 + // first disjunct since we do not have a canonical empty set
1.77 + return ((is_empty() && mr2.is_empty()) ||
1.78 + (start() == mr2.start() && end() == mr2.end()));
1.79 + }
1.80 +
1.81 + size_t byte_size() const { return _word_size * sizeof(HeapWord); }
1.82 + size_t word_size() const { return _word_size; }
1.83 +
1.84 + bool is_empty() const { return word_size() == 0; }
1.85 +};
1.86 +
1.87 +// For iteration over MemRegion's.
1.88 +
1.89 +class MemRegionClosure : public StackObj {
1.90 +public:
1.91 + virtual void do_MemRegion(MemRegion mr) = 0;
1.92 +};
1.93 +
1.94 +// A ResourceObj version of MemRegionClosure
1.95 +
1.96 +class MemRegionClosureRO: public MemRegionClosure {
1.97 +public:
1.98 + void* operator new(size_t size, ResourceObj::allocation_type type) {
1.99 + return ResourceObj::operator new(size, type);
1.100 + }
1.101 + void* operator new(size_t size, Arena *arena) {
1.102 + return ResourceObj::operator new(size, arena);
1.103 + }
1.104 + void* operator new(size_t size) {
1.105 + return ResourceObj::operator new(size);
1.106 + }
1.107 +
1.108 + void operator delete(void* p) {} // nothing to do
1.109 +};
