Mercurial > hg > graal-jvmci-8
view src/share/vm/memory/cardTableRS.hpp @ 20304:a22acf6d7598
8048112: G1 Full GC needs to support the case when the very first region is not available
Summary: Refactor preparation for compaction during Full GC so that it lazily initializes the first compaction point. This also avoids problems later when the first region may not be committed. Also reviewed by K. Barrett.
Reviewed-by: brutisso
author | tschatzl |
---|---|
date | Mon, 21 Jul 2014 10:00:31 +0200 |
parents | bd902affe102 |
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_CARDTABLERS_HPP #define SHARE_VM_MEMORY_CARDTABLERS_HPP #include "memory/cardTableModRefBS.hpp" #include "memory/genRemSet.hpp" #include "memory/memRegion.hpp" class Space; class OopsInGenClosure; // This kind of "GenRemSet" uses a card table both as shared data structure // for a mod ref barrier set and for the rem set information. class CardTableRS: public GenRemSet { friend class VMStructs; // Below are private classes used in impl. friend class VerifyCTSpaceClosure; friend class ClearNoncleanCardWrapper; static jbyte clean_card_val() { return CardTableModRefBS::clean_card; } static intptr_t clean_card_row() { return CardTableModRefBS::clean_card_row; } static bool card_is_dirty_wrt_gen_iter(jbyte cv) { return CardTableModRefBS::card_is_dirty_wrt_gen_iter(cv); } CardTableModRefBSForCTRS* _ct_bs; virtual void younger_refs_in_space_iterate(Space* sp, OopsInGenClosure* cl); void verify_space(Space* s, HeapWord* gen_start); enum ExtendedCardValue { youngergen_card = CardTableModRefBS::CT_MR_BS_last_reserved + 1, // These are for parallel collection. // There are three P (parallel) youngergen card values. In general, this // needs to be more than the number of generations (including the perm // gen) that might have younger_refs_do invoked on them separately. So // if we add more gens, we have to add more values. youngergenP1_card = CardTableModRefBS::CT_MR_BS_last_reserved + 2, youngergenP2_card = CardTableModRefBS::CT_MR_BS_last_reserved + 3, youngergenP3_card = CardTableModRefBS::CT_MR_BS_last_reserved + 4, cur_youngergen_and_prev_nonclean_card = CardTableModRefBS::CT_MR_BS_last_reserved + 5 }; // An array that contains, for each generation, the card table value last // used as the current value for a younger_refs_do iteration of that // portion of the table. (The perm gen is index 0; other gens are at // their level plus 1. They youngest gen is in the table, but will // always have the value "clean_card".) jbyte* _last_cur_val_in_gen; jbyte _cur_youngergen_card_val; int _regions_to_iterate; jbyte cur_youngergen_card_val() { return _cur_youngergen_card_val; } void set_cur_youngergen_card_val(jbyte v) { _cur_youngergen_card_val = v; } bool is_prev_youngergen_card_val(jbyte v) { return youngergen_card <= v && v < cur_youngergen_and_prev_nonclean_card && v != _cur_youngergen_card_val; } // Return a youngergen_card_value that is not currently in use. jbyte find_unused_youngergenP_card_value(); public: CardTableRS(MemRegion whole_heap, int max_covered_regions); ~CardTableRS(); // *** GenRemSet functions. GenRemSet::Name rs_kind() { return GenRemSet::CardTable; } CardTableRS* as_CardTableRS() { return this; } CardTableModRefBS* ct_bs() { return _ct_bs; } // Override. void prepare_for_younger_refs_iterate(bool parallel); // Card table entries are cleared before application; "blk" is // responsible for dirtying if the oop is still older-to-younger after // closure application. void younger_refs_iterate(Generation* g, OopsInGenClosure* blk); void inline_write_ref_field_gc(void* field, oop new_val) { jbyte* byte = _ct_bs->byte_for(field); *byte = youngergen_card; } void write_ref_field_gc_work(void* field, oop new_val) { inline_write_ref_field_gc(field, new_val); } // Override. Might want to devirtualize this in the same fashion as // above. Ensures that the value of the card for field says that it's // a younger card in the current collection. virtual void write_ref_field_gc_par(void* field, oop new_val); void resize_covered_region(MemRegion new_region); bool is_aligned(HeapWord* addr) { return _ct_bs->is_card_aligned(addr); } void verify(); void verify_aligned_region_empty(MemRegion mr); void clear(MemRegion mr) { _ct_bs->clear(mr); } void clear_into_younger(Generation* old_gen); void invalidate(MemRegion mr, bool whole_heap = false) { _ct_bs->invalidate(mr, whole_heap); } void invalidate_or_clear(Generation* old_gen); static uintx ct_max_alignment_constraint() { return CardTableModRefBS::ct_max_alignment_constraint(); } jbyte* byte_for(void* p) { return _ct_bs->byte_for(p); } jbyte* byte_after(void* p) { return _ct_bs->byte_after(p); } HeapWord* addr_for(jbyte* p) { return _ct_bs->addr_for(p); } bool is_prev_nonclean_card_val(jbyte v) { return youngergen_card <= v && v <= cur_youngergen_and_prev_nonclean_card && v != _cur_youngergen_card_val; } static bool youngergen_may_have_been_dirty(jbyte cv) { return cv == CardTableRS::cur_youngergen_and_prev_nonclean_card; } }; class ClearNoncleanCardWrapper: public MemRegionClosure { DirtyCardToOopClosure* _dirty_card_closure; CardTableRS* _ct; bool _is_par; private: // Clears the given card, return true if the corresponding card should be // processed. inline bool clear_card(jbyte* entry); // Work methods called by the clear_card() inline bool clear_card_serial(jbyte* entry); inline bool clear_card_parallel(jbyte* entry); // check alignment of pointer bool is_word_aligned(jbyte* entry); public: ClearNoncleanCardWrapper(DirtyCardToOopClosure* dirty_card_closure, CardTableRS* ct); void do_MemRegion(MemRegion mr); }; #endif // SHARE_VM_MEMORY_CARDTABLERS_HPP