1 /*
   2  * Copyright (c) 2016, 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.
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  23  */
  24 
  25 #ifndef SHARE_VM_GC_G1_G1BARRIERSET_INLINE_HPP
  26 #define SHARE_VM_GC_G1_G1BARRIERSET_INLINE_HPP
  27 
  28 #include "gc/g1/g1BarrierSet.hpp"
  29 #include "gc/g1/g1CardTable.hpp"
  30 #include "gc/shared/accessBarrierSupport.inline.hpp"
  31 #include "oops/oop.inline.hpp"
  32 
  33 template <DecoratorSet decorators, typename T>
  34 inline void G1BarrierSet::write_ref_field_pre(T* field) {
  35   if (HasDecorator<decorators, AS_DEST_NOT_INITIALIZED>::value ||
  36       HasDecorator<decorators, AS_NO_KEEPALIVE>::value) {
  37     return;
  38   }
  39 
  40   T heap_oop = RawAccess<MO_VOLATILE>::oop_load(field);
  41   if (!oopDesc::is_null(heap_oop)) {
  42     enqueue(oopDesc::decode_heap_oop_not_null(heap_oop));
  43   }
  44 }
  45 
  46 template <DecoratorSet decorators, typename T>
  47 inline void G1BarrierSet::write_ref_field_post(T* field, oop new_val) {
  48   volatile jbyte* byte = _card_table->byte_for(field);
  49   if (*byte != G1CardTable::g1_young_card_val()) {
  50     // Take a slow path for cards in old
  51     write_ref_field_post_slow(byte);
  52   }
  53 }
  54 
  55 inline void G1BarrierSet::enqueue_if_weak_or_archive(DecoratorSet decorators, oop value) {
  56   assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
  57   // Archive roots need to be enqueued since they add subgraphs to the
  58   // Java heap that were not there at the snapshot when marking started.
  59   // Weak and phantom references also need enqueueing for similar reasons.
  60   const bool in_archive_root   = (decorators & IN_ARCHIVE_ROOT) != 0;
  61   const bool on_strong_oop_ref = (decorators & ON_STRONG_OOP_REF) != 0;
  62   const bool peek              = (decorators & AS_NO_KEEPALIVE) != 0;
  63   const bool needs_enqueue     = in_archive_root || (!peek && !on_strong_oop_ref);
  64 
  65   if (needs_enqueue && value != NULL) {
  66     enqueue(value);
  67   }
  68 }
  69 
  70 template <DecoratorSet decorators, typename BarrierSetT>
  71 template <typename T>
  72 inline oop G1BarrierSet::AccessBarrier<decorators, BarrierSetT>::
  73 oop_load_not_in_heap(T* addr) {
  74   oop value = ModRef::oop_load_not_in_heap(addr);
  75   enqueue_if_weak_or_archive(decorators, value);
  76   return value;
  77 }
  78 
  79 template <DecoratorSet decorators, typename BarrierSetT>
  80 template <typename T>
  81 inline oop G1BarrierSet::AccessBarrier<decorators, BarrierSetT>::
  82 oop_load_in_heap(T* addr) {
  83   oop value = ModRef::oop_load_in_heap(addr);
  84   enqueue_if_weak_or_archive(decorators, value);
  85   return value;
  86 }
  87 
  88 template <DecoratorSet decorators, typename BarrierSetT>
  89 inline oop G1BarrierSet::AccessBarrier<decorators, BarrierSetT>::
  90 oop_load_in_heap_at(oop base, ptrdiff_t offset) {
  91   oop value = ModRef::oop_load_in_heap_at(base, offset);
  92   enqueue_if_weak_or_archive(AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset), value);
  93   return value;
  94 }
  95 
  96 template <DecoratorSet decorators, typename BarrierSetT>
  97 template <typename T>
  98 inline void G1BarrierSet::AccessBarrier<decorators, BarrierSetT>::
  99 oop_store_not_in_heap(T* addr, oop new_value) {
 100   if (HasDecorator<decorators, IN_CONCURRENT_ROOT>::value) {
 101     // For roots not scanned in a safepoint, we have to apply SATB barriers
 102     // even for roots.
 103     G1BarrierSet *bs = barrier_set_cast<G1BarrierSet>(BarrierSet::barrier_set());
 104     bs->write_ref_field_pre<decorators>(addr);
 105   }
 106   Raw::oop_store(addr, new_value);
 107 }
 108 
 109 #endif // SHARE_VM_GC_G1_G1BARRIERSET_INLINE_HPP