Mercurial > hg > truffle
view src/share/vm/memory/genRemSet.hpp @ 21863:f4822d122041 jdk8u45-b11
Merge
author | asaha |
---|---|
date | Sat, 07 Mar 2015 16:26:10 -0800 |
parents | 55fb97c4c58d |
children | 284953caf7aa |
line wrap: on
line source
/* * Copyright (c) 2001, 2013, 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_GENREMSET_HPP #define SHARE_VM_MEMORY_GENREMSET_HPP #include "oops/oop.hpp" // A GenRemSet provides ways of iterating over pointers accross generations. // (This is especially useful for older-to-younger.) class Generation; class BarrierSet; class OopsInGenClosure; class CardTableRS; // Helper to remember modified oops in all klasses. class KlassRemSet { bool _accumulate_modified_oops; public: KlassRemSet() : _accumulate_modified_oops(false) {} void set_accumulate_modified_oops(bool value) { _accumulate_modified_oops = value; } bool accumulate_modified_oops() { return _accumulate_modified_oops; } bool mod_union_is_clear(); void clear_mod_union(); }; class GenRemSet: public CHeapObj<mtGC> { friend class Generation; BarrierSet* _bs; KlassRemSet _klass_rem_set; public: enum Name { CardTable, Other }; GenRemSet(BarrierSet * bs) : _bs(bs) {} GenRemSet() : _bs(NULL) {} virtual Name rs_kind() = 0; // These are for dynamic downcasts. Unfortunately that it names the // possible subtypes (but not that they are subtypes!) Return NULL if // the cast is invalide. virtual CardTableRS* as_CardTableRS() { return NULL; } // Return the barrier set associated with "this." BarrierSet* bs() { return _bs; } // Set the barrier set. void set_bs(BarrierSet* bs) { _bs = bs; } KlassRemSet* klass_rem_set() { return &_klass_rem_set; } // Do any (sequential) processing necessary to prepare for (possibly // "parallel", if that arg is true) calls to younger_refs_iterate. virtual void prepare_for_younger_refs_iterate(bool parallel) = 0; // Apply the "do_oop" method of "blk" to (exactly) all oop locations // 1) that are in objects allocated in "g" at the time of the last call // to "save_Marks", and // 2) that point to objects in younger generations. virtual void younger_refs_iterate(Generation* g, OopsInGenClosure* blk) = 0; virtual void younger_refs_in_space_iterate(Space* sp, OopsInGenClosure* cl) = 0; // This method is used to notify the remembered set that "new_val" has // been written into "field" by the garbage collector. void write_ref_field_gc(void* field, oop new_val); protected: virtual void write_ref_field_gc_work(void* field, oop new_val) = 0; public: // A version of the above suitable for use by parallel collectors. virtual void write_ref_field_gc_par(void* field, oop new_val) = 0; // Resize one of the regions covered by the remembered set. virtual void resize_covered_region(MemRegion new_region) = 0; // If the rem set imposes any alignment restrictions on boundaries // within the heap, this function tells whether they are met. virtual bool is_aligned(HeapWord* addr) = 0; // If the RS (or BS) imposes an aligment constraint on maximum heap size. // (This must be static, and dispatch on "nm", because it is called // before an RS is created.) static uintx max_alignment_constraint(Name nm); virtual void verify() = 0; // Verify that the remembered set has no entries for // the heap interval denoted by mr. If there are any // alignment constraints on the remembered set, only the // part of the region that is aligned is checked. // // alignment boundaries // +--------+-------+--------+-------+ // [ region mr ) // [ part checked ) virtual void verify_aligned_region_empty(MemRegion mr) = 0; // If appropriate, print some information about the remset on "tty". virtual void print() {} // Informs the RS that the given memregion contains no references to // younger generations. virtual void clear(MemRegion mr) = 0; // Informs the RS that there are no references to generations // younger than gen from generations gen and older. // The parameter clear_perm indicates if the perm_gen's // remembered set should also be processed/cleared. virtual void clear_into_younger(Generation* old_gen) = 0; // Informs the RS that refs in the given "mr" may have changed // arbitrarily, and therefore may contain old-to-young pointers. // If "whole heap" is true, then this invalidation is part of an // invalidation of the whole heap, which an implementation might // handle differently than that of a sub-part of the heap. virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0; // Informs the RS that refs in this generation // may have changed arbitrarily, and therefore may contain // old-to-young pointers in arbitrary locations. virtual void invalidate_or_clear(Generation* old_gen) = 0; }; #endif // SHARE_VM_MEMORY_GENREMSET_HPP