1 /* 2 * Copyright (c) 2001, 2018, 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/g1BarrierSet.inline.hpp" 27 #include "gc/g1/g1BarrierSetAssembler.hpp" 28 #include "gc/g1/g1CardTable.inline.hpp" 29 #include "gc/g1/g1CollectedHeap.inline.hpp" 30 #include "gc/g1/g1ThreadLocalData.hpp" 31 #include "gc/g1/heapRegion.hpp" 32 #include "gc/g1/satbMarkQueue.hpp" 33 #include "logging/log.hpp" 34 #include "oops/access.inline.hpp" 35 #include "oops/compressedOops.inline.hpp" 36 #include "oops/oop.inline.hpp" 37 #include "runtime/mutexLocker.hpp" 38 #include "runtime/thread.inline.hpp" 39 #include "utilities/macros.hpp" 40 #ifdef COMPILER1 41 #include "gc/g1/c1/g1BarrierSetC1.hpp" 42 #endif 43 44 class G1BarrierSetC1; 45 46 SATBMarkQueueSet G1BarrierSet::_satb_mark_queue_set; 47 DirtyCardQueueSet G1BarrierSet::_dirty_card_queue_set; 48 49 G1BarrierSet::G1BarrierSet(G1CardTable* card_table) : 50 CardTableBarrierSet(make_barrier_set_assembler<G1BarrierSetAssembler>(), 51 make_barrier_set_c1<G1BarrierSetC1>(), 52 card_table, 53 BarrierSet::FakeRtti(BarrierSet::G1BarrierSet)) {} 54 55 void G1BarrierSet::enqueue(oop pre_val) { 56 // Nulls should have been already filtered. 57 assert(oopDesc::is_oop(pre_val, true), "Error"); 58 59 if (!_satb_mark_queue_set.is_active()) return; 60 Thread* thr = Thread::current(); 61 if (thr->is_Java_thread()) { 62 G1ThreadLocalData::satb_mark_queue(thr).enqueue(pre_val); 63 } else { 64 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag); 65 _satb_mark_queue_set.shared_satb_queue()->enqueue(pre_val); 66 } 67 } 68 69 void G1BarrierSet::write_ref_array_pre_oop_entry(oop* dst, size_t length) { 70 G1BarrierSet *bs = barrier_set_cast<G1BarrierSet>(BarrierSet::barrier_set()); 71 bs->write_ref_array_pre(dst, length, false); 72 } 73 74 void G1BarrierSet::write_ref_array_pre_narrow_oop_entry(narrowOop* dst, size_t length) { 75 G1BarrierSet *bs = barrier_set_cast<G1BarrierSet>(BarrierSet::barrier_set()); 76 bs->write_ref_array_pre(dst, length, false); 77 } 78 79 void G1BarrierSet::write_ref_array_post_entry(HeapWord* dst, size_t length) { 80 G1BarrierSet *bs = barrier_set_cast<G1BarrierSet>(BarrierSet::barrier_set()); 81 bs->G1BarrierSet::write_ref_array(dst, length); 82 } 83 84 template <class T> void 85 G1BarrierSet::write_ref_array_pre_work(T* dst, size_t count) { 86 if (!_satb_mark_queue_set.is_active()) return; 87 T* elem_ptr = dst; 88 for (size_t i = 0; i < count; i++, elem_ptr++) { 89 T heap_oop = RawAccess<>::oop_load(elem_ptr); 90 if (!CompressedOops::is_null(heap_oop)) { 91 enqueue(CompressedOops::decode_not_null(heap_oop)); 92 } 93 } 94 } 95 96 void G1BarrierSet::write_ref_array_pre(oop* dst, size_t count, bool dest_uninitialized) { 97 if (!dest_uninitialized) { 98 write_ref_array_pre_work(dst, count); 99 } 100 } 101 102 void G1BarrierSet::write_ref_array_pre(narrowOop* dst, size_t count, bool dest_uninitialized) { 103 if (!dest_uninitialized) { 104 write_ref_array_pre_work(dst, count); 105 } 106 } 107 108 void G1BarrierSet::write_ref_field_post_slow(volatile jbyte* byte) { 109 // In the slow path, we know a card is not young 110 assert(*byte != G1CardTable::g1_young_card_val(), "slow path invoked without filtering"); 111 OrderAccess::storeload(); 112 if (*byte != G1CardTable::dirty_card_val()) { 113 *byte = G1CardTable::dirty_card_val(); 114 Thread* thr = Thread::current(); 115 if (thr->is_Java_thread()) { 116 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte); 117 } else { 118 MutexLockerEx x(Shared_DirtyCardQ_lock, 119 Mutex::_no_safepoint_check_flag); 120 _dirty_card_queue_set.shared_dirty_card_queue()->enqueue(byte); 121 } 122 } 123 } 124 125 void G1BarrierSet::invalidate(MemRegion mr) { 126 if (mr.is_empty()) { 127 return; 128 } 129 volatile jbyte* byte = _card_table->byte_for(mr.start()); 130 jbyte* last_byte = _card_table->byte_for(mr.last()); 131 Thread* thr = Thread::current(); 132 // skip all consecutive young cards 133 for (; byte <= last_byte && *byte == G1CardTable::g1_young_card_val(); byte++); 134 135 if (byte <= last_byte) { 136 OrderAccess::storeload(); 137 // Enqueue if necessary. 138 if (thr->is_Java_thread()) { 139 for (; byte <= last_byte; byte++) { 140 if (*byte == G1CardTable::g1_young_card_val()) { 141 continue; 142 } 143 if (*byte != G1CardTable::dirty_card_val()) { 144 *byte = G1CardTable::dirty_card_val(); 145 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte); 146 } 147 } 148 } else { 149 MutexLockerEx x(Shared_DirtyCardQ_lock, 150 Mutex::_no_safepoint_check_flag); 151 for (; byte <= last_byte; byte++) { 152 if (*byte == G1CardTable::g1_young_card_val()) { 153 continue; 154 } 155 if (*byte != G1CardTable::dirty_card_val()) { 156 *byte = G1CardTable::dirty_card_val(); 157 _dirty_card_queue_set.shared_dirty_card_queue()->enqueue(byte); 158 } 159 } 160 } 161 } 162 } 163 164 void G1BarrierSet::on_thread_create(Thread* thread) { 165 // Create thread local data 166 G1ThreadLocalData::create(thread); 167 } 168 169 void G1BarrierSet::on_thread_destroy(Thread* thread) { 170 // Destroy thread local data 171 G1ThreadLocalData::destroy(thread); 172 } 173 174 void G1BarrierSet::on_thread_attach(JavaThread* thread) { 175 // This method initializes the SATB and dirty card queues before a 176 // JavaThread is added to the Java thread list. Right now, we don't 177 // have to do anything to the dirty card queue (it should have been 178 // activated when the thread was created), but we have to activate 179 // the SATB queue if the thread is created while a marking cycle is 180 // in progress. The activation / de-activation of the SATB queues at 181 // the beginning / end of a marking cycle is done during safepoints 182 // so we have to make sure this method is called outside one to be 183 // able to safely read the active field of the SATB queue set. Right 184 // now, it is called just before the thread is added to the Java 185 // thread list in the Threads::add() method. That method is holding 186 // the Threads_lock which ensures we are outside a safepoint. We 187 // cannot do the obvious and set the active field of the SATB queue 188 // when the thread is created given that, in some cases, safepoints 189 // might happen between the JavaThread constructor being called and the 190 // thread being added to the Java thread list (an example of this is 191 // when the structure for the DestroyJavaVM thread is created). 192 assert(!SafepointSynchronize::is_at_safepoint(), "We should not be at a safepoint"); 193 assert(!G1ThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active"); 194 assert(G1ThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty"); 195 assert(G1ThreadLocalData::dirty_card_queue(thread).is_active(), "Dirty card queue should be active"); 196 197 // If we are creating the thread during a marking cycle, we should 198 // set the active field of the SATB queue to true. 199 if (_satb_mark_queue_set.is_active()) { 200 G1ThreadLocalData::satb_mark_queue(thread).set_active(true); 201 } 202 } 203 204 void G1BarrierSet::on_thread_detach(JavaThread* thread) { 205 // Flush any deferred card marks, SATB buffers and dirty card queue buffers 206 CardTableBarrierSet::on_thread_detach(thread); 207 G1ThreadLocalData::satb_mark_queue(thread).flush(); 208 G1ThreadLocalData::dirty_card_queue(thread).flush(); 209 }