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/interfaceSupport.inline.hpp" 38 #include "runtime/mutexLocker.hpp" 39 #include "runtime/thread.inline.hpp" 40 #include "utilities/macros.hpp" 41 #ifdef COMPILER1 42 #include "gc/g1/c1/g1BarrierSetC1.hpp" 43 #endif 44 #ifdef COMPILER2 45 #include "gc/g1/c2/g1BarrierSetC2.hpp" 46 #endif 47 48 class G1BarrierSetC1; 49 class G1BarrierSetC2; 50 51 SATBMarkQueueSet G1BarrierSet::_satb_mark_queue_set; 52 DirtyCardQueueSet G1BarrierSet::_dirty_card_queue_set; 53 54 G1BarrierSet::G1BarrierSet(G1CardTable* card_table) : 55 CardTableBarrierSet(make_barrier_set_assembler<G1BarrierSetAssembler>(), 56 make_barrier_set_c1<G1BarrierSetC1>(), 57 make_barrier_set_c2<G1BarrierSetC2>(), 58 card_table, 59 BarrierSet::FakeRtti(BarrierSet::G1BarrierSet)) {} 60 61 void G1BarrierSet::enqueue(oop pre_val) { 62 // Nulls should have been already filtered. 63 assert(oopDesc::is_oop(pre_val, true), "Error"); 64 65 if (!_satb_mark_queue_set.is_active()) return; 66 Thread* thr = Thread::current(); 67 if (thr->is_Java_thread()) { 68 G1ThreadLocalData::satb_mark_queue(thr).enqueue(pre_val); 69 } else { 70 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag); 71 _satb_mark_queue_set.shared_satb_queue()->enqueue(pre_val); 72 } 73 } 74 75 template <class T> void 76 G1BarrierSet::write_ref_array_pre_work(T* dst, size_t count) { 77 if (!_satb_mark_queue_set.is_active()) return; 78 T* elem_ptr = dst; 79 for (size_t i = 0; i < count; i++, elem_ptr++) { 80 T heap_oop = RawAccess<>::oop_load(elem_ptr); 81 if (!CompressedOops::is_null(heap_oop)) { 82 enqueue(CompressedOops::decode_not_null(heap_oop)); 83 } 84 } 85 } 86 87 void G1BarrierSet::write_ref_array_pre(oop* dst, size_t count, bool dest_uninitialized) { 88 if (!dest_uninitialized) { 89 write_ref_array_pre_work(dst, count); 90 } 91 } 92 93 void G1BarrierSet::write_ref_array_pre(narrowOop* dst, size_t count, bool dest_uninitialized) { 94 if (!dest_uninitialized) { 95 write_ref_array_pre_work(dst, count); 96 } 97 } 98 99 void G1BarrierSet::write_ref_field_post_slow(volatile jbyte* byte) { 100 // In the slow path, we know a card is not young 101 assert(*byte != G1CardTable::g1_young_card_val(), "slow path invoked without filtering"); 102 OrderAccess::storeload(); 103 if (*byte != G1CardTable::dirty_card_val()) { 104 *byte = G1CardTable::dirty_card_val(); 105 Thread* thr = Thread::current(); 106 if (thr->is_Java_thread()) { 107 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte); 108 } else { 109 MutexLockerEx x(Shared_DirtyCardQ_lock, 110 Mutex::_no_safepoint_check_flag); 111 _dirty_card_queue_set.shared_dirty_card_queue()->enqueue(byte); 112 } 113 } 114 } 115 116 void G1BarrierSet::invalidate(MemRegion mr) { 117 if (mr.is_empty()) { 118 return; 119 } 120 volatile jbyte* byte = _card_table->byte_for(mr.start()); 121 jbyte* last_byte = _card_table->byte_for(mr.last()); 122 Thread* thr = Thread::current(); 123 // skip all consecutive young cards 124 for (; byte <= last_byte && *byte == G1CardTable::g1_young_card_val(); byte++); 125 126 if (byte <= last_byte) { 127 OrderAccess::storeload(); 128 // Enqueue if necessary. 129 if (thr->is_Java_thread()) { 130 for (; byte <= last_byte; byte++) { 131 if (*byte == G1CardTable::g1_young_card_val()) { 132 continue; 133 } 134 if (*byte != G1CardTable::dirty_card_val()) { 135 *byte = G1CardTable::dirty_card_val(); 136 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte); 137 } 138 } 139 } else { 140 MutexLockerEx x(Shared_DirtyCardQ_lock, 141 Mutex::_no_safepoint_check_flag); 142 for (; byte <= last_byte; byte++) { 143 if (*byte == G1CardTable::g1_young_card_val()) { 144 continue; 145 } 146 if (*byte != G1CardTable::dirty_card_val()) { 147 *byte = G1CardTable::dirty_card_val(); 148 _dirty_card_queue_set.shared_dirty_card_queue()->enqueue(byte); 149 } 150 } 151 } 152 } 153 } 154 155 void G1BarrierSet::on_thread_create(Thread* thread) { 156 // Create thread local data 157 G1ThreadLocalData::create(thread); 158 } 159 160 void G1BarrierSet::on_thread_destroy(Thread* thread) { 161 // Destroy thread local data 162 G1ThreadLocalData::destroy(thread); 163 } 164 165 void G1BarrierSet::on_thread_attach(JavaThread* thread) { 166 // This method initializes the SATB and dirty card queues before a 167 // JavaThread is added to the Java thread list. Right now, we don't 168 // have to do anything to the dirty card queue (it should have been 169 // activated when the thread was created), but we have to activate 170 // the SATB queue if the thread is created while a marking cycle is 171 // in progress. The activation / de-activation of the SATB queues at 172 // the beginning / end of a marking cycle is done during safepoints 173 // so we have to make sure this method is called outside one to be 174 // able to safely read the active field of the SATB queue set. Right 175 // now, it is called just before the thread is added to the Java 176 // thread list in the Threads::add() method. That method is holding 177 // the Threads_lock which ensures we are outside a safepoint. We 178 // cannot do the obvious and set the active field of the SATB queue 179 // when the thread is created given that, in some cases, safepoints 180 // might happen between the JavaThread constructor being called and the 181 // thread being added to the Java thread list (an example of this is 182 // when the structure for the DestroyJavaVM thread is created). 183 assert(!SafepointSynchronize::is_at_safepoint(), "We should not be at a safepoint"); 184 assert(!G1ThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active"); 185 assert(G1ThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty"); 186 assert(G1ThreadLocalData::dirty_card_queue(thread).is_active(), "Dirty card queue should be active"); 187 188 // If we are creating the thread during a marking cycle, we should 189 // set the active field of the SATB queue to true. 190 if (_satb_mark_queue_set.is_active()) { 191 G1ThreadLocalData::satb_mark_queue(thread).set_active(true); 192 } 193 } 194 195 void G1BarrierSet::on_thread_detach(JavaThread* thread) { 196 // Flush any deferred card marks, SATB buffers and dirty card queue buffers 197 CardTableBarrierSet::on_thread_detach(thread); 198 G1ThreadLocalData::satb_mark_queue(thread).flush(); 199 G1ThreadLocalData::dirty_card_queue(thread).flush(); 200 }