1 /* 2 * Copyright (c) 2001, 2010, 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. 22 * 23 */ 24 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_CARDTABLEEXTENSION_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_CARDTABLEEXTENSION_HPP 27 28 #include "memory/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, int max_covered_regions) : 57 CardTableModRefBS(whole_heap, max_covered_regions) { } 58 59 // Too risky for the 4/10/02 putback 60 // BarrierSet::Name kind() { return BarrierSet::CardTableExtension; } 61 62 // Scavenge support 63 void scavenge_contents(ObjectStartArray* start_array, 64 MutableSpace* sp, 65 HeapWord* space_top, 66 PSPromotionManager* pm); 67 68 void scavenge_contents_parallel(ObjectStartArray* start_array, 69 MutableSpace* sp, 70 HeapWord* space_top, 71 PSPromotionManager* pm, 72 uint stripe_number); 73 74 // Verification 75 static void verify_all_young_refs_imprecise(); 76 static void verify_all_young_refs_precise(); 77 78 bool addr_is_marked_imprecise(void *addr); 79 bool addr_is_marked_precise(void *addr); 80 81 void set_card_newgen(void* addr) { jbyte* p = byte_for(addr); *p = verify_card; } 82 83 // Testers for entries 84 static bool card_is_dirty(int value) { return value == dirty_card; } 85 static bool card_is_newgen(int value) { return value == youngergen_card; } 86 static bool card_is_clean(int value) { return value == clean_card; } 87 static bool card_is_verify(int value) { return value == verify_card; } 88 89 // Card marking 90 void inline_write_ref_field_gc(void* field, oop new_val) { 91 jbyte* byte = byte_for(field); 92 *byte = youngergen_card; 93 } 94 95 // Adaptive size policy support 96 // Allows adjustment of the base and size of the covered regions 97 void resize_covered_region(MemRegion new_region); 98 // Finds the covered region to resize based on the start address 99 // of the covered regions. 100 void resize_covered_region_by_start(MemRegion new_region); 101 // Finds the covered region to resize based on the end address 102 // of the covered regions. 103 void resize_covered_region_by_end(int changed_region, MemRegion new_region); 104 // Finds the lowest start address of a covered region that is 105 // previous (i.e., lower index) to the covered region with index "ind". 106 HeapWord* lowest_prev_committed_start(int ind) const; 107 108 #ifdef ASSERT 109 110 bool is_valid_card_address(jbyte* addr) { 111 return (addr >= _byte_map) && (addr < _byte_map + _byte_map_size); 112 } 113 114 #endif // ASSERT 115 }; 116 117 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_CARDTABLEEXTENSION_HPP