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/orderAccess.hpp"
  41 #include "runtime/thread.inline.hpp"
  42 #include "utilities/macros.hpp"
  43 #ifdef COMPILER1
  44 #include "gc/g1/c1/g1BarrierSetC1.hpp"
  45 #endif
  46 #ifdef COMPILER2
  47 #include "gc/g1/c2/g1BarrierSetC2.hpp"
  48 #endif
  49 
  50 class G1BarrierSetC1;
  51 class G1BarrierSetC2;
  52 
  53 G1BarrierSet::G1BarrierSet(G1CardTable* card_table) :
  54   CardTableBarrierSet(make_barrier_set_assembler<G1BarrierSetAssembler>(),
  55                       make_barrier_set_c1<G1BarrierSetC1>(),
  56                       make_barrier_set_c2<G1BarrierSetC2>(),
  57                       card_table,
  58                       BarrierSet::FakeRtti(BarrierSet::G1BarrierSet)),
  59   _satb_mark_queue_buffer_allocator("SATB Buffer Allocator", G1SATBBufferSize),
  60   _dirty_card_queue_buffer_allocator("DC Buffer Allocator", G1UpdateBufferSize),
  61   _satb_mark_queue_set(&_satb_mark_queue_buffer_allocator),
  62   _dirty_card_queue_set(DirtyCardQ_CBL_mon, &_dirty_card_queue_buffer_allocator),
  63   _shared_dirty_card_queue(&_dirty_card_queue_set)
  64 {}
  65 
  66 void G1BarrierSet::enqueue(oop pre_val) {
  67   // Nulls should have been already filtered.
  68   assert(oopDesc::is_oop(pre_val, true), "Error");
  69   G1ThreadLocalData::satb_mark_queue(Thread::current()).enqueue(pre_val);
  70 }
  71 
  72 template <class T> void
  73 G1BarrierSet::write_ref_array_pre_work(T* dst, size_t count) {
  74   if (!_satb_mark_queue_set.is_active()) return;
  75   T* elem_ptr = dst;
  76   for (size_t i = 0; i < count; i++, elem_ptr++) {
  77     T heap_oop = RawAccess<>::oop_load(elem_ptr);
  78     if (!CompressedOops::is_null(heap_oop)) {
  79       enqueue(CompressedOops::decode_not_null(heap_oop));
  80     }
  81   }
  82 }
  83 
  84 void G1BarrierSet::write_ref_array_pre(oop* dst, size_t count, bool dest_uninitialized) {
  85   if (!dest_uninitialized) {
  86     write_ref_array_pre_work(dst, count);
  87   }
  88 }
  89 
  90 void G1BarrierSet::write_ref_array_pre(narrowOop* dst, size_t count, bool dest_uninitialized) {
  91   if (!dest_uninitialized) {
  92     write_ref_array_pre_work(dst, count);
  93   }
  94 }
  95 
  96 void G1BarrierSet::write_ref_field_post_slow(volatile CardValue* byte) {
  97   // In the slow path, we know a card is not young
  98   assert(*byte != G1CardTable::g1_young_card_val(), "slow path invoked without filtering");
  99   OrderAccess::storeload();
 100   if (*byte != G1CardTable::dirty_card_val()) {
 101     *byte = G1CardTable::dirty_card_val();
 102     Thread* thr = Thread::current();
 103     G1ThreadLocalData::dirty_card_queue(thr).enqueue(byte);
 104   }
 105 }
 106 
 107 void G1BarrierSet::invalidate(MemRegion mr) {
 108   if (mr.is_empty()) {
 109     return;
 110   }
 111   volatile CardValue* byte = _card_table->byte_for(mr.start());
 112   CardValue* last_byte = _card_table->byte_for(mr.last());
 113   // skip initial young cards
 114   for (; byte <= last_byte && *byte == G1CardTable::g1_young_card_val(); byte++);
 115 
 116   if (byte <= last_byte) {
 117     OrderAccess::storeload();
 118     // Enqueue if necessary.
 119     Thread* thr = Thread::current();
 120     G1DirtyCardQueue& queue = G1ThreadLocalData::dirty_card_queue(thr);
 121     for (; byte <= last_byte; byte++) {
 122       CardValue bv = *byte;
 123       if ((bv != G1CardTable::g1_young_card_val()) &&
 124           (bv != G1CardTable::dirty_card_val())) {
 125         *byte = G1CardTable::dirty_card_val();
 126         queue.enqueue(byte);
 127       }
 128     }
 129   }
 130 }
 131 
 132 void G1BarrierSet::on_thread_create(Thread* thread) {
 133   // Create thread local data
 134   G1ThreadLocalData::create(thread);
 135 }
 136 
 137 void G1BarrierSet::on_thread_destroy(Thread* thread) {
 138   // Destroy thread local data
 139   G1ThreadLocalData::destroy(thread);
 140 }
 141 
 142 void G1BarrierSet::on_thread_attach(Thread* thread) {
 143   assert(!G1ThreadLocalData::satb_mark_queue(thread).is_active(), "SATB queue should not be active");
 144   assert(G1ThreadLocalData::satb_mark_queue(thread).is_empty(), "SATB queue should be empty");
 145   assert(G1ThreadLocalData::dirty_card_queue(thread).is_active(), "Dirty card queue should be active");
 146   // Can't assert that the DCQ is empty.  There is early execution on
 147   // the main thread, before it gets added to the threads list, which
 148   // is where this is called.  That execution may enqueue dirty cards.
 149 
 150   // If we are creating the thread during a marking cycle, we should
 151   // set the active field of the SATB queue to true.  That involves
 152   // copying the global is_active value to this thread's queue.
 153   bool is_satb_active = _satb_mark_queue_set.is_active();
 154   G1ThreadLocalData::satb_mark_queue(thread).set_active(is_satb_active);
 155 }
 156 
 157 void G1BarrierSet::on_thread_detach(Thread* thread) {
 158   // Flush any deferred card marks.
 159   CardTableBarrierSet::on_thread_detach(thread);
 160   G1ThreadLocalData::satb_mark_queue(thread).flush();
 161   G1ThreadLocalData::dirty_card_queue(thread).flush();
 162 }