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. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" 27 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp" 28 #include "gc_implementation/g1/heapRegion.hpp" 29 #include "gc_implementation/g1/satbQueue.hpp" 30 #include "oops/oop.inline.hpp" 31 #include "runtime/atomic.inline.hpp" 32 #include "runtime/mutexLocker.hpp" 33 #include "runtime/orderAccess.inline.hpp" 34 #include "runtime/thread.inline.hpp" 35 36 G1SATBCardTableModRefBS::G1SATBCardTableModRefBS( 37 MemRegion whole_heap, 38 const BarrierSet::FakeRtti& fake_rtti) : 39 CardTableModRefBS(whole_heap, fake_rtti.add_tag(BarrierSet::G1SATBCT)) 40 { } 41 42 void G1SATBCardTableModRefBS::enqueue(oop pre_val) { 43 // Nulls should have been already filtered. 44 assert(pre_val->is_oop(true), "Error"); 45 46 if (!JavaThread::satb_mark_queue_set().is_active()) return; 47 Thread* thr = Thread::current(); 48 if (thr->is_Java_thread()) { 49 JavaThread* jt = (JavaThread*)thr; 50 jt->satb_mark_queue().enqueue(pre_val); 51 } else { 52 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag); 53 JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val); 54 } 55 } 56 57 template <class T> void 58 G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) { 59 if (!JavaThread::satb_mark_queue_set().is_active()) return; 60 T* elem_ptr = dst; 61 for (int i = 0; i < count; i++, elem_ptr++) { 62 T heap_oop = oopDesc::load_heap_oop(elem_ptr); 63 if (!oopDesc::is_null(heap_oop)) { 64 enqueue(oopDesc::decode_heap_oop_not_null(heap_oop)); 65 } 66 } 67 } 68 69 void G1SATBCardTableModRefBS::write_ref_array_pre(oop* dst, int count, bool dest_uninitialized) { 70 if (!dest_uninitialized) { 71 write_ref_array_pre_work(dst, count); 72 } 73 } 74 void G1SATBCardTableModRefBS::write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized) { 75 if (!dest_uninitialized) { 76 write_ref_array_pre_work(dst, count); 77 } 78 } 79 80 bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) { 81 jbyte val = _byte_map[card_index]; 82 // It's already processed 83 if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) { 84 return false; 85 } 86 87 if (val == g1_young_gen) { 88 // the card is for a young gen region. We don't need to keep track of all pointers into young 89 return false; 90 } 91 92 // Cached bit can be installed either on a clean card or on a claimed card. 93 jbyte new_val = val; 94 if (val == clean_card_val()) { 95 new_val = (jbyte)deferred_card_val(); 96 } else { 97 if (val & claimed_card_val()) { 98 new_val = val | (jbyte)deferred_card_val(); 99 } 100 } 101 if (new_val != val) { 102 Atomic::cmpxchg(new_val, &_byte_map[card_index], val); 103 } 104 return true; 105 } 106 107 void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) { 108 jbyte *const first = byte_for(mr.start()); 109 jbyte *const last = byte_after(mr.last()); 110 111 // Below we may use an explicit loop instead of memset() because on 112 // certain platforms memset() can give concurrent readers phantom zeros. 113 if (UseMemSetInBOT) { 114 memset(first, g1_young_gen, last - first); 115 } else { 116 for (jbyte* i = first; i < last; i++) { 117 *i = g1_young_gen; 118 } 119 } 120 } 121 122 #ifndef PRODUCT 123 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) { 124 verify_region(mr, g1_young_gen, true); 125 } 126 #endif 127 128 void G1SATBCardTableLoggingModRefBSChangedListener::on_commit(uint start_idx, size_t num_regions, bool zero_filled) { 129 // Default value for a clean card on the card table is -1. So we cannot take advantage of the zero_filled parameter. 130 MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords); 131 _card_table->clear(mr); 132 } 133 134 G1SATBCardTableLoggingModRefBS:: 135 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap) : 136 G1SATBCardTableModRefBS(whole_heap, BarrierSet::FakeRtti(G1SATBCTLogging)), 137 _dcqs(JavaThread::dirty_card_queue_set()), 138 _listener() 139 { 140 _listener.set_card_table(this); 141 } 142 143 void G1SATBCardTableLoggingModRefBS::initialize(G1RegionToSpaceMapper* mapper) { 144 mapper->set_mapping_changed_listener(&_listener); 145 146 _byte_map_size = mapper->reserved().byte_size(); 147 148 _guard_index = cards_required(_whole_heap.word_size()) - 1; 149 _last_valid_index = _guard_index - 1; 150 151 HeapWord* low_bound = _whole_heap.start(); 152 HeapWord* high_bound = _whole_heap.end(); 153 154 _cur_covered_regions = 1; 155 _covered[0] = _whole_heap; 156 157 _byte_map = (jbyte*) mapper->reserved().start(); 158 byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift); 159 assert(byte_for(low_bound) == &_byte_map[0], "Checking start of map"); 160 assert(byte_for(high_bound-1) <= &_byte_map[_last_valid_index], "Checking end of map"); 161 162 if (TraceCardTableModRefBS) { 163 gclog_or_tty->print_cr("G1SATBCardTableModRefBS::G1SATBCardTableModRefBS: "); 164 gclog_or_tty->print_cr(" " 165 " &_byte_map[0]: " INTPTR_FORMAT 166 " &_byte_map[_last_valid_index]: " INTPTR_FORMAT, 167 p2i(&_byte_map[0]), 168 p2i(&_byte_map[_last_valid_index])); 169 gclog_or_tty->print_cr(" " 170 " byte_map_base: " INTPTR_FORMAT, 171 p2i(byte_map_base)); 172 } 173 } 174 175 void 176 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field, 177 oop new_val, 178 bool release) { 179 volatile jbyte* byte = byte_for(field); 180 if (*byte == g1_young_gen) { 181 return; 182 } 183 OrderAccess::storeload(); 184 if (*byte != dirty_card) { 185 *byte = dirty_card; 186 Thread* thr = Thread::current(); 187 if (thr->is_Java_thread()) { 188 JavaThread* jt = (JavaThread*)thr; 189 jt->dirty_card_queue().enqueue(byte); 190 } else { 191 MutexLockerEx x(Shared_DirtyCardQ_lock, 192 Mutex::_no_safepoint_check_flag); 193 _dcqs.shared_dirty_card_queue()->enqueue(byte); 194 } 195 } 196 } 197 198 void 199 G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field, 200 oop new_val) { 201 uintptr_t field_uint = (uintptr_t)field; 202 uintptr_t new_val_uint = cast_from_oop<uintptr_t>(new_val); 203 uintptr_t comb = field_uint ^ new_val_uint; 204 comb = comb >> HeapRegion::LogOfHRGrainBytes; 205 if (comb == 0) return; 206 if (new_val == NULL) return; 207 // Otherwise, log it. 208 G1SATBCardTableLoggingModRefBS* g1_bs = 209 barrier_set_cast<G1SATBCardTableLoggingModRefBS>(G1CollectedHeap::heap()->barrier_set()); 210 g1_bs->write_ref_field_work(field, new_val); 211 } 212 213 void 214 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) { 215 volatile jbyte* byte = byte_for(mr.start()); 216 jbyte* last_byte = byte_for(mr.last()); 217 Thread* thr = Thread::current(); 218 if (whole_heap) { 219 while (byte <= last_byte) { 220 *byte = dirty_card; 221 byte++; 222 } 223 } else { 224 // skip all consecutive young cards 225 for (; byte <= last_byte && *byte == g1_young_gen; byte++); 226 227 if (byte <= last_byte) { 228 OrderAccess::storeload(); 229 // Enqueue if necessary. 230 if (thr->is_Java_thread()) { 231 JavaThread* jt = (JavaThread*)thr; 232 for (; byte <= last_byte; byte++) { 233 if (*byte == g1_young_gen) { 234 continue; 235 } 236 if (*byte != dirty_card) { 237 *byte = dirty_card; 238 jt->dirty_card_queue().enqueue(byte); 239 } 240 } 241 } else { 242 MutexLockerEx x(Shared_DirtyCardQ_lock, 243 Mutex::_no_safepoint_check_flag); 244 for (; byte <= last_byte; byte++) { 245 if (*byte == g1_young_gen) { 246 continue; 247 } 248 if (*byte != dirty_card) { 249 *byte = dirty_card; 250 _dcqs.shared_dirty_card_queue()->enqueue(byte); 251 } 252 } 253 } 254 } 255 } 256 }