Mercurial > hg > graal-jvmci-8
view src/share/vm/memory/memRegion.hpp @ 3992:d1bdeef3e3e2
7098282: G1: assert(interval >= 0) failed: Sanity check, referencePolicy.cpp: 76
Summary: There is a race between one thread successfully forwarding and copying the klass mirror for the SoftReference class (including the static master clock) and another thread attempting to use the master clock while attempting to discover a soft reference object. Maintain a shadow copy of the soft reference master clock and use the shadow during reference discovery and reference processing.
Reviewed-by: tonyp, brutisso, ysr
author | johnc |
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date | Wed, 12 Oct 2011 10:25:51 -0700 |
parents | f95d63e2154a |
children | d2a62e0f25eb |
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/* * Copyright (c) 2000, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_MEMORY_MEMREGION_HPP #define SHARE_VM_MEMORY_MEMREGION_HPP #include "memory/allocation.hpp" #include "utilities/debug.hpp" #include "utilities/globalDefinitions.hpp" // 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 }; #endif // SHARE_VM_MEMORY_MEMREGION_HPP