1 /* 2 * Copyright (c) 2001, 2013, 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 #include "precompiled.hpp" 26 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp" 27 #include "gc_implementation/g1/heapRegion.hpp" 28 #include "gc_implementation/g1/satbQueue.hpp" 29 #include "runtime/mutexLocker.hpp" 30 #include "runtime/orderAccess.inline.hpp" 31 #include "runtime/thread.inline.hpp" 32 33 G1SATBCardTableModRefBS::G1SATBCardTableModRefBS(MemRegion whole_heap, 34 int max_covered_regions) : 35 CardTableModRefBSForCTRS(whole_heap, max_covered_regions) 36 { 37 _kind = G1SATBCT; 38 } 39 40 41 void G1SATBCardTableModRefBS::enqueue(oop pre_val) { 42 // Nulls should have been already filtered. 43 assert(pre_val->is_oop(true), "Error"); 44 45 if (!JavaThread::satb_mark_queue_set().is_active()) return; 46 Thread* thr = Thread::current(); 47 if (thr->is_Java_thread()) { 48 JavaThread* jt = (JavaThread*)thr; 49 jt->satb_mark_queue().enqueue(pre_val); 50 } else { 51 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag); 52 JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val); 53 } 54 } 55 56 template <class T> void 57 G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) { 58 if (!JavaThread::satb_mark_queue_set().is_active()) return; 59 T* elem_ptr = dst; 60 for (int i = 0; i < count; i++, elem_ptr++) { 61 T heap_oop = oopDesc::load_heap_oop(elem_ptr); 62 if (!oopDesc::is_null(heap_oop)) { 63 enqueue(oopDesc::decode_heap_oop_not_null(heap_oop)); 64 } 65 } 66 } 67 68 bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) { 69 jbyte val = _byte_map[card_index]; 70 // It's already processed 71 if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) { 72 return false; 73 } 74 75 if (val == g1_young_gen) { 76 // the card is for a young gen region. We don't need to keep track of all pointers into young 77 return false; 78 } 79 80 // Cached bit can be installed either on a clean card or on a claimed card. 81 jbyte new_val = val; 82 if (val == clean_card_val()) { 83 new_val = (jbyte)deferred_card_val(); 84 } else { 85 if (val & claimed_card_val()) { 86 new_val = val | (jbyte)deferred_card_val(); 87 } 88 } 89 if (new_val != val) { 90 Atomic::cmpxchg(new_val, &_byte_map[card_index], val); 91 } 92 return true; 93 } 94 95 void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) { 96 jbyte *const first = byte_for(mr.start()); 97 jbyte *const last = byte_after(mr.last()); 98 99 // Below we may use an explicit loop instead of memset() because on 100 // certain platforms memset() can give concurrent readers phantom zeros. 101 if (UseMemSetInBOT) { 102 memset(first, g1_young_gen, last - first); 103 } else { 104 for (jbyte* i = first; i < last; i++) { 105 *i = g1_young_gen; 106 } 107 } 108 } 109 110 #ifndef PRODUCT 111 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) { 112 verify_region(mr, g1_young_gen, true); 113 } 114 #endif 115 116 G1SATBCardTableLoggingModRefBS:: 117 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap, 118 int max_covered_regions) : 119 G1SATBCardTableModRefBS(whole_heap, max_covered_regions), 120 _dcqs(JavaThread::dirty_card_queue_set()) 121 { 122 _kind = G1SATBCTLogging; 123 } 124 125 void 126 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field, 127 oop new_val, 128 bool release) { 129 volatile jbyte* byte = byte_for(field); 130 if (*byte == g1_young_gen) { 131 return; 132 } 133 OrderAccess::storeload(); 134 if (*byte != dirty_card) { 135 *byte = dirty_card; 136 Thread* thr = Thread::current(); 137 if (thr->is_Java_thread()) { 138 JavaThread* jt = (JavaThread*)thr; 139 jt->dirty_card_queue().enqueue(byte); 140 } else { 141 MutexLockerEx x(Shared_DirtyCardQ_lock, 142 Mutex::_no_safepoint_check_flag); 143 _dcqs.shared_dirty_card_queue()->enqueue(byte); 144 } 145 } 146 } 147 148 void 149 G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field, 150 oop new_val) { 151 uintptr_t field_uint = (uintptr_t)field; 152 uintptr_t new_val_uint = cast_from_oop<uintptr_t>(new_val); 153 uintptr_t comb = field_uint ^ new_val_uint; 154 comb = comb >> HeapRegion::LogOfHRGrainBytes; 155 if (comb == 0) return; 156 if (new_val == NULL) return; 157 // Otherwise, log it. 158 G1SATBCardTableLoggingModRefBS* g1_bs = 159 (G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set(); 160 g1_bs->write_ref_field_work(field, new_val); 161 } 162 163 void 164 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) { 165 volatile jbyte* byte = byte_for(mr.start()); 166 jbyte* last_byte = byte_for(mr.last()); 167 Thread* thr = Thread::current(); 168 if (whole_heap) { 169 while (byte <= last_byte) { 170 *byte = dirty_card; 171 byte++; 172 } 173 } else { 174 // skip all consecutive young cards 175 for (; byte <= last_byte && *byte == g1_young_gen; byte++); 176 177 if (byte <= last_byte) { 178 OrderAccess::storeload(); 179 // Enqueue if necessary. 180 if (thr->is_Java_thread()) { 181 JavaThread* jt = (JavaThread*)thr; 182 for (; byte <= last_byte; byte++) { 183 if (*byte == g1_young_gen) { 184 continue; 185 } 186 if (*byte != dirty_card) { 187 *byte = dirty_card; 188 jt->dirty_card_queue().enqueue(byte); 189 } 190 } 191 } else { 192 MutexLockerEx x(Shared_DirtyCardQ_lock, 193 Mutex::_no_safepoint_check_flag); 194 for (; byte <= last_byte; byte++) { 195 if (*byte == g1_young_gen) { 196 continue; 197 } 198 if (*byte != dirty_card) { 199 *byte = dirty_card; 200 _dcqs.shared_dirty_card_queue()->enqueue(byte); 201 } 202 } 203 } 204 } 205 } 206 }