g1SATBCardTableModRefBS.cpp revision 11857:d0fbf661cc16
1/* 2 * Copyright (c) 2001, 2016, 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/g1/g1CollectedHeap.inline.hpp" 27#include "gc/g1/g1SATBCardTableModRefBS.inline.hpp" 28#include "gc/g1/heapRegion.hpp" 29#include "gc/g1/satbMarkQueue.hpp" 30#include "gc/shared/memset_with_concurrent_readers.hpp" 31#include "logging/log.hpp" 32#include "oops/oop.inline.hpp" 33#include "runtime/atomic.hpp" 34#include "runtime/mutexLocker.hpp" 35#include "runtime/orderAccess.inline.hpp" 36#include "runtime/thread.inline.hpp" 37 38G1SATBCardTableModRefBS::G1SATBCardTableModRefBS( 39 MemRegion whole_heap, 40 const BarrierSet::FakeRtti& fake_rtti) : 41 CardTableModRefBS(whole_heap, fake_rtti.add_tag(BarrierSet::G1SATBCT)) 42{ } 43 44void G1SATBCardTableModRefBS::enqueue(oop pre_val) { 45 // Nulls should have been already filtered. 46 assert(pre_val->is_oop(true), "Error"); 47 48 if (!JavaThread::satb_mark_queue_set().is_active()) return; 49 Thread* thr = Thread::current(); 50 if (thr->is_Java_thread()) { 51 JavaThread* jt = (JavaThread*)thr; 52 jt->satb_mark_queue().enqueue(pre_val); 53 } else { 54 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag); 55 JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val); 56 } 57} 58 59template <class T> void 60G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) { 61 if (!JavaThread::satb_mark_queue_set().is_active()) return; 62 T* elem_ptr = dst; 63 for (int i = 0; i < count; i++, elem_ptr++) { 64 T heap_oop = oopDesc::load_heap_oop(elem_ptr); 65 if (!oopDesc::is_null(heap_oop)) { 66 enqueue(oopDesc::decode_heap_oop_not_null(heap_oop)); 67 } 68 } 69} 70 71void G1SATBCardTableModRefBS::write_ref_array_pre(oop* dst, int count, bool dest_uninitialized) { 72 if (!dest_uninitialized) { 73 write_ref_array_pre_work(dst, count); 74 } 75} 76void G1SATBCardTableModRefBS::write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized) { 77 if (!dest_uninitialized) { 78 write_ref_array_pre_work(dst, count); 79 } 80} 81 82bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) { 83 jbyte val = _byte_map[card_index]; 84 // It's already processed 85 if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) { 86 return false; 87 } 88 89 // Cached bit can be installed either on a clean card or on a claimed card. 90 jbyte new_val = val; 91 if (val == clean_card_val()) { 92 new_val = (jbyte)deferred_card_val(); 93 } else { 94 if (val & claimed_card_val()) { 95 new_val = val | (jbyte)deferred_card_val(); 96 } 97 } 98 if (new_val != val) { 99 Atomic::cmpxchg(new_val, &_byte_map[card_index], val); 100 } 101 return true; 102} 103 104void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) { 105 jbyte *const first = byte_for(mr.start()); 106 jbyte *const last = byte_after(mr.last()); 107 108 memset_with_concurrent_readers(first, g1_young_gen, last - first); 109} 110 111#ifndef PRODUCT 112void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) { 113 verify_region(mr, g1_young_gen, true); 114} 115#endif 116 117void G1SATBCardTableLoggingModRefBSChangedListener::on_commit(uint start_idx, size_t num_regions, bool zero_filled) { 118 // Default value for a clean card on the card table is -1. So we cannot take advantage of the zero_filled parameter. 119 MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords); 120 _card_table->clear(mr); 121} 122 123G1SATBCardTableLoggingModRefBS:: 124G1SATBCardTableLoggingModRefBS(MemRegion whole_heap) : 125 G1SATBCardTableModRefBS(whole_heap, BarrierSet::FakeRtti(G1SATBCTLogging)), 126 _dcqs(JavaThread::dirty_card_queue_set()), 127 _listener() 128{ 129 _listener.set_card_table(this); 130} 131 132void G1SATBCardTableLoggingModRefBS::initialize(G1RegionToSpaceMapper* mapper) { 133 mapper->set_mapping_changed_listener(&_listener); 134 135 _byte_map_size = mapper->reserved().byte_size(); 136 137 _guard_index = cards_required(_whole_heap.word_size()) - 1; 138 _last_valid_index = _guard_index - 1; 139 140 HeapWord* low_bound = _whole_heap.start(); 141 HeapWord* high_bound = _whole_heap.end(); 142 143 _cur_covered_regions = 1; 144 _covered[0] = _whole_heap; 145 146 _byte_map = (jbyte*) mapper->reserved().start(); 147 byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift); 148 assert(byte_for(low_bound) == &_byte_map[0], "Checking start of map"); 149 assert(byte_for(high_bound-1) <= &_byte_map[_last_valid_index], "Checking end of map"); 150 151 log_trace(gc, barrier)("G1SATBCardTableModRefBS::G1SATBCardTableModRefBS: "); 152 log_trace(gc, barrier)(" &_byte_map[0]: " INTPTR_FORMAT " &_byte_map[_last_valid_index]: " INTPTR_FORMAT, 153 p2i(&_byte_map[0]), p2i(&_byte_map[_last_valid_index])); 154 log_trace(gc, barrier)(" byte_map_base: " INTPTR_FORMAT, p2i(byte_map_base)); 155} 156 157void 158G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field, 159 oop new_val, 160 bool release) { 161 volatile jbyte* byte = byte_for(field); 162 if (*byte == g1_young_gen) { 163 return; 164 } 165 OrderAccess::storeload(); 166 if (*byte != dirty_card) { 167 *byte = dirty_card; 168 Thread* thr = Thread::current(); 169 if (thr->is_Java_thread()) { 170 JavaThread* jt = (JavaThread*)thr; 171 jt->dirty_card_queue().enqueue(byte); 172 } else { 173 MutexLockerEx x(Shared_DirtyCardQ_lock, 174 Mutex::_no_safepoint_check_flag); 175 _dcqs.shared_dirty_card_queue()->enqueue(byte); 176 } 177 } 178} 179 180void 181G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) { 182 volatile jbyte* byte = byte_for(mr.start()); 183 jbyte* last_byte = byte_for(mr.last()); 184 Thread* thr = Thread::current(); 185 if (whole_heap) { 186 while (byte <= last_byte) { 187 *byte = dirty_card; 188 byte++; 189 } 190 } else { 191 // skip all consecutive young cards 192 for (; byte <= last_byte && *byte == g1_young_gen; byte++); 193 194 if (byte <= last_byte) { 195 OrderAccess::storeload(); 196 // Enqueue if necessary. 197 if (thr->is_Java_thread()) { 198 JavaThread* jt = (JavaThread*)thr; 199 for (; byte <= last_byte; byte++) { 200 if (*byte == g1_young_gen) { 201 continue; 202 } 203 if (*byte != dirty_card) { 204 *byte = dirty_card; 205 jt->dirty_card_queue().enqueue(byte); 206 } 207 } 208 } else { 209 MutexLockerEx x(Shared_DirtyCardQ_lock, 210 Mutex::_no_safepoint_check_flag); 211 for (; byte <= last_byte; byte++) { 212 if (*byte == g1_young_gen) { 213 continue; 214 } 215 if (*byte != dirty_card) { 216 *byte = dirty_card; 217 _dcqs.shared_dirty_card_queue()->enqueue(byte); 218 } 219 } 220 } 221 } 222 } 223} 224 225void G1SATBCardTableModRefBS::write_ref_nmethod_post(oop* dst, nmethod* nm) { 226 oop obj = oopDesc::load_heap_oop(dst); 227 if (obj != NULL) { 228 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 229 HeapRegion* hr = g1h->heap_region_containing(obj); 230 hr->add_strong_code_root(nm); 231 } 232} 233 234class G1EnsureLastRefToRegion : public OopClosure { 235 G1CollectedHeap* _g1h; 236 HeapRegion* _hr; 237 oop* _dst; 238 239 bool _value; 240public: 241 G1EnsureLastRefToRegion(G1CollectedHeap* g1h, HeapRegion* hr, oop* dst) : 242 _g1h(g1h), _hr(hr), _dst(dst), _value(true) {} 243 244 void do_oop(oop* p) { 245 if (_value && p != _dst) { 246 oop obj = oopDesc::load_heap_oop(p); 247 if (obj != NULL) { 248 HeapRegion* hr = _g1h->heap_region_containing(obj); 249 if (hr == _hr) { 250 // Another reference to the same region. 251 _value = false; 252 } 253 } 254 } 255 } 256 void do_oop(narrowOop* p) { ShouldNotReachHere(); } 257 bool value() const { return _value; } 258}; 259 260void G1SATBCardTableModRefBS::write_ref_nmethod_pre(oop* dst, nmethod* nm) { 261 oop obj = oopDesc::load_heap_oop(dst); 262 if (obj != NULL) { 263 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 264 HeapRegion* hr = g1h->heap_region_containing(obj); 265 G1EnsureLastRefToRegion ensure_last_ref(g1h, hr, dst); 266 nm->oops_do(&ensure_last_ref); 267 if (ensure_last_ref.value()) { 268 // Last reference to this region, remove the nmethod from the rset. 269 hr->remove_strong_code_root(nm); 270 } 271 } 272} 273