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8387713: Shenandoah: Rework native card table barrier #749

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8387713: Shenandoah: Rework native card table barrier #749

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2 changes: 1 addition & 1 deletion src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -125,7 +125,7 @@ class ShenandoahBarrierSet: public BarrierSet {
inline oop oop_xchg(DecoratorSet decorators, T* addr, oop new_value);

template <DecoratorSet decorators, typename T>
void write_ref_field_post(T* field);
void write_ref_field_post(T* field, oop new_value);

void write_ref_array(HeapWord* start, size_t count);

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31 changes: 18 additions & 13 deletions src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.inline.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -189,23 +189,28 @@ inline void ShenandoahBarrierSet::keep_alive_if_weak(DecoratorSet decorators, oo
}

template <DecoratorSet decorators, typename T>
inline void ShenandoahBarrierSet::write_ref_field_post(T* field) {
inline void ShenandoahBarrierSet::write_ref_field_post(T* field, oop new_value) {
assert(ShenandoahCardBarrier, "Should have been checked by caller");
if (_heap->is_in_young(field)) {
// Young field stores do not require card mark.

if (new_value == nullptr) {
// Null reference stores do not require card mark.
return;
}
T heap_oop = RawAccess<>::oop_load(field);
if (CompressedOops::is_null(heap_oop)) {
// Null reference store do not require card mark.

if (_heap->is_in_young(field)) {
// Young field stores do not require card mark.
return;
}
oop obj = CompressedOops::decode_not_null(heap_oop);
if (!_heap->is_in_young(obj)) {

if (!_heap->is_in_young(new_value)) {
// Not an old->young reference store.
return;
}

volatile CardTable::CardValue* byte = card_table()->byte_for(field);
if (UseCondCardMark && (*byte == CardTable::dirty_card_val())) {
return;
}
*byte = CardTable::dirty_card_val();
}

Expand Down Expand Up @@ -296,7 +301,7 @@ inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_st
oop_store_common(addr, value);
if (ShenandoahCardBarrier) {
ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
bs->write_ref_field_post<decorators>(addr);
bs->write_ref_field_post<decorators>(addr, value);
}
}

Expand All @@ -320,7 +325,7 @@ inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_ato
ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
oop result = bs->oop_cmpxchg(decorators, addr, compare_value, new_value);
if (ShenandoahCardBarrier) {
bs->write_ref_field_post<decorators>(addr);
bs->write_ref_field_post<decorators>(addr, new_value);
}
return result;
}
Expand All @@ -333,7 +338,7 @@ inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_ato
auto addr = AccessInternal::oop_field_addr<decorators>(base, offset);
oop result = bs->oop_cmpxchg(resolved_decorators, addr, compare_value, new_value);
if (ShenandoahCardBarrier) {
bs->write_ref_field_post<decorators>(addr);
bs->write_ref_field_post<decorators>(addr, new_value);
}
return result;
}
Expand All @@ -353,7 +358,7 @@ inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_ato
ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
oop result = bs->oop_xchg(decorators, addr, new_value);
if (ShenandoahCardBarrier) {
bs->write_ref_field_post<decorators>(addr);
bs->write_ref_field_post<decorators>(addr, new_value);
}
return result;
}
Expand All @@ -366,7 +371,7 @@ inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_ato
auto addr = AccessInternal::oop_field_addr<decorators>(base, offset);
oop result = bs->oop_xchg(resolved_decorators, addr, new_value);
if (ShenandoahCardBarrier) {
bs->write_ref_field_post<decorators>(addr);
bs->write_ref_field_post<decorators>(addr, new_value);
}
return result;
}
Expand Down