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 class MutableSpace; 26 class ObjectStartArray; 27 class PSPromotionManager; 28 class GCTaskQueue; 29 30 class CardTableExtension : public CardTableModRefBS { 31 private: 32 // Support methods for resizing the card table. 33 // resize_commit_uncommit() returns true if the pages were committed or 34 // uncommitted 35 bool resize_commit_uncommit(int changed_region, MemRegion new_region); 36 void resize_update_card_table_entries(int changed_region, 37 MemRegion new_region); 38 void resize_update_committed_table(int changed_region, MemRegion new_region); 39 void resize_update_covered_table(int changed_region, MemRegion new_region); 40 41 protected: 42 43 static void verify_all_young_refs_precise_helper(MemRegion mr); 44 45 public: 46 enum ExtendedCardValue { 47 youngergen_card = CardTableModRefBS::CT_MR_BS_last_reserved + 1, 48 verify_card = CardTableModRefBS::CT_MR_BS_last_reserved + 5 49 }; 50 51 CardTableExtension(MemRegion whole_heap, int max_covered_regions) : 52 CardTableModRefBS(whole_heap, max_covered_regions) { } 53 54 // Too risky for the 4/10/02 putback 55 // BarrierSet::Name kind() { return BarrierSet::CardTableExtension; } 56 57 // Scavenge support 58 void scavenge_contents(ObjectStartArray* start_array, 59 MutableSpace* sp, 60 HeapWord* space_top, 61 PSPromotionManager* pm); 62 63 void scavenge_contents_parallel(ObjectStartArray* start_array, 64 MutableSpace* sp, 65 HeapWord* space_top, 66 PSPromotionManager* pm, 67 uint stripe_number); 68 69 // Verification 70 static void verify_all_young_refs_imprecise(); 71 static void verify_all_young_refs_precise(); 72 73 bool addr_is_marked_imprecise(void *addr); 74 bool addr_is_marked_precise(void *addr); 75 76 void set_card_newgen(void* addr) { jbyte* p = byte_for(addr); *p = verify_card; } 77 78 // Testers for entries 79 static bool card_is_dirty(int value) { return value == dirty_card; } 80 static bool card_is_newgen(int value) { return value == youngergen_card; } 81 static bool card_is_clean(int value) { return value == clean_card; } 82 static bool card_is_verify(int value) { return value == verify_card; } 83 84 // Card marking 85 void inline_write_ref_field_gc(void* field, oop new_val) { 86 jbyte* byte = byte_for(field); 87 *byte = youngergen_card; 88 } 89 90 // Adaptive size policy support 91 // Allows adjustment of the base and size of the covered regions 92 void resize_covered_region(MemRegion new_region); 93 // Finds the covered region to resize based on the start address 94 // of the covered regions. 95 void resize_covered_region_by_start(MemRegion new_region); 96 // Finds the covered region to resize based on the end address 97 // of the covered regions. 98 void resize_covered_region_by_end(int changed_region, MemRegion new_region); 99 // Finds the lowest start address of a covered region that is 100 // previous (i.e., lower index) to the covered region with index "ind". 101 HeapWord* lowest_prev_committed_start(int ind) const; 102 103 #ifdef ASSERT 104 105 bool is_valid_card_address(jbyte* addr) { 106 return (addr >= _byte_map) && (addr < _byte_map + _byte_map_size); 107 } 108 109 #endif // ASSERT 110 };