1 /*
   2  * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
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  23  */
  24 
  25 #ifndef SHARE_VM_GC_PARALLEL_CARDTABLEEXTENSION_HPP
  26 #define SHARE_VM_GC_PARALLEL_CARDTABLEEXTENSION_HPP
  27 
  28 #include "gc/shared/cardTableModRefBS.hpp"
  29 
  30 class MutableSpace;
  31 class ObjectStartArray;
  32 class PSPromotionManager;
  33 class GCTaskQueue;
  34 
  35 class CardTableExtension : public CardTableModRefBS {
  36  private:
  37   // Support methods for resizing the card table.
  38   // resize_commit_uncommit() returns true if the pages were committed or
  39   // uncommitted
  40   bool resize_commit_uncommit(int changed_region, MemRegion new_region);
  41   void resize_update_card_table_entries(int changed_region,
  42                                         MemRegion new_region);
  43   void resize_update_committed_table(int changed_region, MemRegion new_region);
  44   void resize_update_covered_table(int changed_region, MemRegion new_region);
  45 
  46  protected:
  47 
  48   static void verify_all_young_refs_precise_helper(MemRegion mr);
  49 
  50  public:
  51   enum ExtendedCardValue {
  52     youngergen_card   = CardTableModRefBS::CT_MR_BS_last_reserved + 1,
  53     verify_card       = CardTableModRefBS::CT_MR_BS_last_reserved + 5
  54   };
  55 
  56   CardTableExtension(MemRegion whole_heap) :
  57     CardTableModRefBS(
  58       whole_heap,
  59       BarrierSet::FakeRtti(BarrierSet::CardTableExtension))
  60     { }
  61 
  62   // Scavenge support
  63   void scavenge_contents_parallel(ObjectStartArray* start_array,
  64                                   MutableSpace* sp,
  65                                   HeapWord* space_top,
  66                                   PSPromotionManager* pm,
  67                                   uint stripe_number,
  68                                   uint stripe_total);
  69 
  70   // Verification
  71   static void verify_all_young_refs_imprecise();
  72   static void verify_all_young_refs_precise();
  73 
  74   bool addr_is_marked_imprecise(void *addr);
  75   bool addr_is_marked_precise(void *addr);
  76 
  77   void set_card_newgen(void* addr)   { jbyte* p = byte_for(addr); *p = verify_card; }
  78 
  79   // Testers for entries
  80   static bool card_is_dirty(int value)      { return value == dirty_card; }
  81   static bool card_is_newgen(int value)     { return value == youngergen_card; }
  82   static bool card_is_clean(int value)      { return value == clean_card; }
  83   static bool card_is_verify(int value)     { return value == verify_card; }
  84 
  85   // Card marking
  86   void inline_write_ref_field_gc(void* field, oop new_val) {
  87     jbyte* byte = byte_for(field);
  88     *byte = youngergen_card;
  89   }
  90 
  91   // Adaptive size policy support
  92   // Allows adjustment of the base and size of the covered regions
  93   void resize_covered_region(MemRegion new_region);
  94   // Finds the covered region to resize based on the start address
  95   // of the covered regions.
  96   void resize_covered_region_by_start(MemRegion new_region);
  97   // Finds the covered region to resize based on the end address
  98   // of the covered regions.
  99   void resize_covered_region_by_end(int changed_region, MemRegion new_region);
 100   // Finds the lowest start address of a covered region that is
 101   // previous (i.e., lower index) to the covered region with index "ind".
 102   HeapWord* lowest_prev_committed_start(int ind) const;
 103 
 104 #ifdef ASSERT
 105 
 106   bool is_valid_card_address(jbyte* addr) {
 107     return (addr >= _byte_map) && (addr < _byte_map + _byte_map_size);
 108   }
 109 
 110 #endif // ASSERT
 111 };
 112 
 113 template<>
 114 struct BarrierSet::GetName<CardTableExtension> {
 115   static const BarrierSet::Name value = BarrierSet::CardTableExtension;
 116 };
 117 
 118 #endif // SHARE_VM_GC_PARALLEL_CARDTABLEEXTENSION_HPP