1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/memory/genRemSet.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,153 @@
1.4 +/*
1.5 + * Copyright (c) 2001, 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_GENREMSET_HPP
1.29 +#define SHARE_VM_MEMORY_GENREMSET_HPP
1.30 +
1.31 +#include "oops/oop.hpp"
1.32 +
1.33 +// A GenRemSet provides ways of iterating over pointers accross generations.
1.34 +// (This is especially useful for older-to-younger.)
1.35 +
1.36 +class Generation;
1.37 +class BarrierSet;
1.38 +class OopsInGenClosure;
1.39 +class CardTableRS;
1.40 +
1.41 +// Helper to remember modified oops in all klasses.
1.42 +class KlassRemSet {
1.43 + bool _accumulate_modified_oops;
1.44 + public:
1.45 + KlassRemSet() : _accumulate_modified_oops(false) {}
1.46 + void set_accumulate_modified_oops(bool value) { _accumulate_modified_oops = value; }
1.47 + bool accumulate_modified_oops() { return _accumulate_modified_oops; }
1.48 + bool mod_union_is_clear();
1.49 + void clear_mod_union();
1.50 +};
1.51 +
1.52 +class GenRemSet: public CHeapObj<mtGC> {
1.53 + friend class Generation;
1.54 +
1.55 + BarrierSet* _bs;
1.56 + KlassRemSet _klass_rem_set;
1.57 +
1.58 +public:
1.59 + enum Name {
1.60 + CardTable,
1.61 + Other
1.62 + };
1.63 +
1.64 + GenRemSet(BarrierSet * bs) : _bs(bs) {}
1.65 + GenRemSet() : _bs(NULL) {}
1.66 +
1.67 + virtual Name rs_kind() = 0;
1.68 +
1.69 + // These are for dynamic downcasts. Unfortunately that it names the
1.70 + // possible subtypes (but not that they are subtypes!) Return NULL if
1.71 + // the cast is invalide.
1.72 + virtual CardTableRS* as_CardTableRS() { return NULL; }
1.73 +
1.74 + // Return the barrier set associated with "this."
1.75 + BarrierSet* bs() { return _bs; }
1.76 +
1.77 + // Set the barrier set.
1.78 + void set_bs(BarrierSet* bs) { _bs = bs; }
1.79 +
1.80 + KlassRemSet* klass_rem_set() { return &_klass_rem_set; }
1.81 +
1.82 + // Do any (sequential) processing necessary to prepare for (possibly
1.83 + // "parallel", if that arg is true) calls to younger_refs_iterate.
1.84 + virtual void prepare_for_younger_refs_iterate(bool parallel) = 0;
1.85 +
1.86 + // Apply the "do_oop" method of "blk" to (exactly) all oop locations
1.87 + // 1) that are in objects allocated in "g" at the time of the last call
1.88 + // to "save_Marks", and
1.89 + // 2) that point to objects in younger generations.
1.90 + virtual void younger_refs_iterate(Generation* g, OopsInGenClosure* blk) = 0;
1.91 +
1.92 + virtual void younger_refs_in_space_iterate(Space* sp,
1.93 + OopsInGenClosure* cl) = 0;
1.94 +
1.95 + // This method is used to notify the remembered set that "new_val" has
1.96 + // been written into "field" by the garbage collector.
1.97 + void write_ref_field_gc(void* field, oop new_val);
1.98 +protected:
1.99 + virtual void write_ref_field_gc_work(void* field, oop new_val) = 0;
1.100 +public:
1.101 +
1.102 + // A version of the above suitable for use by parallel collectors.
1.103 + virtual void write_ref_field_gc_par(void* field, oop new_val) = 0;
1.104 +
1.105 + // Resize one of the regions covered by the remembered set.
1.106 + virtual void resize_covered_region(MemRegion new_region) = 0;
1.107 +
1.108 + // If the rem set imposes any alignment restrictions on boundaries
1.109 + // within the heap, this function tells whether they are met.
1.110 + virtual bool is_aligned(HeapWord* addr) = 0;
1.111 +
1.112 + // If the RS (or BS) imposes an aligment constraint on maximum heap size.
1.113 + // (This must be static, and dispatch on "nm", because it is called
1.114 + // before an RS is created.)
1.115 + static uintx max_alignment_constraint(Name nm);
1.116 +
1.117 + virtual void verify() = 0;
1.118 +
1.119 + // Verify that the remembered set has no entries for
1.120 + // the heap interval denoted by mr. If there are any
1.121 + // alignment constraints on the remembered set, only the
1.122 + // part of the region that is aligned is checked.
1.123 + //
1.124 + // alignment boundaries
1.125 + // +--------+-------+--------+-------+
1.126 + // [ region mr )
1.127 + // [ part checked )
1.128 + virtual void verify_aligned_region_empty(MemRegion mr) = 0;
1.129 +
1.130 + // If appropriate, print some information about the remset on "tty".
1.131 + virtual void print() {}
1.132 +
1.133 + // Informs the RS that the given memregion contains no references to
1.134 + // younger generations.
1.135 + virtual void clear(MemRegion mr) = 0;
1.136 +
1.137 + // Informs the RS that there are no references to generations
1.138 + // younger than gen from generations gen and older.
1.139 + // The parameter clear_perm indicates if the perm_gen's
1.140 + // remembered set should also be processed/cleared.
1.141 + virtual void clear_into_younger(Generation* old_gen) = 0;
1.142 +
1.143 + // Informs the RS that refs in the given "mr" may have changed
1.144 + // arbitrarily, and therefore may contain old-to-young pointers.
1.145 + // If "whole heap" is true, then this invalidation is part of an
1.146 + // invalidation of the whole heap, which an implementation might
1.147 + // handle differently than that of a sub-part of the heap.
1.148 + virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0;
1.149 +
1.150 + // Informs the RS that refs in this generation
1.151 + // may have changed arbitrarily, and therefore may contain
1.152 + // old-to-young pointers in arbitrary locations.
1.153 + virtual void invalidate_or_clear(Generation* old_gen) = 0;
1.154 +};
1.155 +
1.156 +#endif // SHARE_VM_MEMORY_GENREMSET_HPP
