1 /* 2 * Copyright (c) 2001, 2019, 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/g1SATBMarkQueueSet.hpp" 31 #include "gc/g1/g1ThreadLocalData.hpp" 32 #include "gc/g1/heapRegion.hpp" 33 #include "gc/shared/satbMarkQueue.hpp" 34 #include "logging/log.hpp" 35 #include "oops/access.inline.hpp" 36 #include "oops/compressedOops.inline.hpp" 37 #include "oops/oop.inline.hpp" 38 #include "runtime/interfaceSupport.inline.hpp" 39 #include "runtime/mutexLocker.hpp" 40 #include "runtime/thread.inline.hpp" 41 #include "utilities/macros.hpp" 42 #ifdef COMPILER1 43 #include "gc/g1/c1/g1BarrierSetC1.hpp" 44 #endif 45 #ifdef COMPILER2 46 #include "gc/g1/c2/g1BarrierSetC2.hpp" 47 #endif 48 49 class G1BarrierSetC1; 50 class G1BarrierSetC2; 51 52 G1BarrierSet::G1BarrierSet(G1CardTable* card_table) : 53 CardTableBarrierSet(make_barrier_set_assembler<G1BarrierSetAssembler>(), 54 make_barrier_set_c1<G1BarrierSetC1>(), 55 make_barrier_set_c2<G1BarrierSetC2>(), 56 card_table, 57 BarrierSet::FakeRtti(BarrierSet::G1BarrierSet)), 58 _satb_mark_queue_buffer_allocator("SATB Buffer Allocator", G1SATBBufferSize), 59 _dirty_card_queue_buffer_allocator("DC Buffer Allocator", G1UpdateBufferSize), 60 _satb_mark_queue_set(), 61 _dirty_card_queue_set() 62 {} 63 64 void G1BarrierSet::enqueue(oop pre_val) { 65 // Nulls should have been already filtered. 66 assert(oopDesc::is_oop(pre_val, true), "Error"); 67 G1ThreadLocalData::satb_mark_queue(Thread::current()).enqueue(pre_val); 68 } 69 70 template <class T> void 71 G1BarrierSet::write_ref_array_pre_work(T* dst, size_t count) { 72 if (!_satb_mark_queue_set.is_active()) return; 73 T* elem_ptr = dst; 74 for (size_t i = 0; i < count; i++, elem_ptr++) { 75 T heap_oop = RawAccess<>::oop_load(elem_ptr); 76 if (!CompressedOops::is_null(heap_oop)) { 77 enqueue(CompressedOops::decode_not_null(heap_oop)); 78 } 79 } 80 } 81 82 void G1BarrierSet::write_ref_array_pre(oop* dst, size_t count, bool dest_uninitialized) { 83 if (!dest_uninitialized) { 84 write_ref_array_pre_work(dst, count); 85 } 86 } 87 88 void G1BarrierSet::write_ref_array_pre(narrowOop* dst, size_t count, bool dest_uninitialized) { 89 if (!dest_uninitialized) { 90 write_ref_array_pre_work(dst, count); 91 } 92 } 93 94 void G1BarrierSet::write_ref_field_post_slow(volatile CardValue* byte) { 95 // In the slow path, we know a card is not young 96 assert(*byte != G1CardTable::g1_young_card_val(), "slow path invoked without filtering"); 97 OrderAccess::storeload(); 98 if (*byte != G1CardTable::dirty_card_val()) { 99 *byte = G1CardTable::dirty_card_val(); 100 Thread* thr = Thread::current(); 101 G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte); 102 } 103 } 104 105 void G1BarrierSet::invalidate(MemRegion mr) { 106 if (mr.is_empty()) { 107 return; 108 } 109 volatile CardValue* byte = _card_table->byte_for(mr.start()); 110 CardValue* last_byte = _card_table->byte_for(mr.last()); 111 // skip initial young cards 112 for (; byte <= last_byte && *byte == G1CardTable::g1_young_card_val(); byte++); 113 114 if (byte <= last_byte) { 115 OrderAccess::storeload(); 116 // Enqueue if necessary. 117 Thread* thr = Thread::current(); 118 G1DirtyCardQueue& queue = G1ThreadLocalData::dirty_card_queue(thr); 119 for (; byte <= last_byte; byte++) { 120 CardValue bv = *byte; 121 if ((bv != G1CardTable::g1_young_card_val()) && 122 (bv != G1CardTable::dirty_card_val())) { 123 *byte = G1CardTable::dirty_card_val(); 124 queue.enqueue(byte); 125 } 126 } 127 } 128 } 129 130 void G1BarrierSet::on_thread_create(Thread* thread) { 131 // Create thread local data 132 G1ThreadLocalData::create(thread); 133 } 134 135 void G1BarrierSet::on_thread_destroy(Thread* thread) { 136 // Destroy thread local data 137 G1ThreadLocalData::destroy(thread); 138 } 139 140 void G1BarrierSet::on_thread_attach(Thread* thread) { 141 assert(!G1ThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active"); 142 assert(G1ThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty"); 143 assert(G1ThreadLocalData::dirty_card_queue(thread).is_active(), "Dirty card queue should be active"); 144 // Can't assert that the DCQ is empty. There is early execution on 145 // the main thread, before it gets added to the threads list, which 146 // is where this is called. That execution may enqueue dirty cards. 147 148 // If we are creating the thread during a marking cycle, we should 149 // set the active field of the SATB queue to true. That involves 150 // copying the global is_active value to this thread's queue, which 151 // is done without any direct synchronization here. 152 // 153 // The activation and deactivation of the SATB queues occurs at the 154 // beginning / end of a marking cycle, and is done during 155 // safepoints. This function is called just before a thread is 156 // added to its corresponding threads list (for Java or non-Java 157 // threads, respectively). 158 // 159 // For Java threads, that's done while holding the Threads_lock, 160 // which ensures we're not at a safepoint, so reading the global 161 // is_active state is synchronized against update. 162 assert(!thread->is_Java_thread() || !SafepointSynchronize::is_at_safepoint(), 163 "Should not be at a safepoint"); 164 // For non-Java threads, thread creation (and list addition) may, 165 // and indeed usually does, occur during a safepoint. But such 166 // creation isn't concurrent with updating the global SATB active 167 // state. 168 bool is_satb_active = _satb_mark_queue_set.is_active(); 169 G1ThreadLocalData::satb_mark_queue(thread).set_active(is_satb_active); 170 } 171 172 void G1BarrierSet::on_thread_detach(Thread* thread) { 173 // Flush any deferred card marks. 174 CardTableBarrierSet::on_thread_detach(thread); 175 G1ThreadLocalData::satb_mark_queue(thread).flush(); 176 G1ThreadLocalData::dirty_card_queue(thread).flush(); 177 } 178 179 BufferNode::Allocator& G1BarrierSet::satb_mark_queue_buffer_allocator() { 180 return _satb_mark_queue_buffer_allocator; 181 } 182 183 BufferNode::Allocator& G1BarrierSet::dirty_card_queue_buffer_allocator() { 184 return _dirty_card_queue_buffer_allocator; 185 }