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src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.inline.hpp

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470   // Hot code path, called from compiler/runtime. Make sure fast path is fast.
471 
472   // Fix up src before doing the copy, if needed.
473   const char gc_state = ShenandoahThreadLocalData::gc_state(Thread::current());
474   if (gc_state != 0 && ShenandoahCloneBarrier) {
475     ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
476     if ((gc_state & ShenandoahHeap::EVACUATION) != 0) {
477       bs->clone_work<true>(src);
478     } else if ((gc_state & ShenandoahHeap::UPDATE_REFS) != 0) {
479       bs->clone_work<false>(src);
480     }
481   }
482 
483   Raw::clone(src, dst, size);
484 
485   // Current allocator never allocates in old, so clone destination is guaranteed to be in young.
486   // Otherwise we need card barriers.
487   shenandoah_assert_in_young_if(nullptr, dst, ShenandoahCardBarrier);
488 }
489 














































































490 template <DecoratorSet decorators, typename BarrierSetT>
491 template <typename T>
492 OopCopyResult ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
493                                                                                                   arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
494                                                                                                   size_t length) {
495   T* src = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw);
496   T* dst = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw);

497 
498   ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
499   bs->arraycopy_barrier(src, dst, length);
500   OopCopyResult result = Raw::oop_arraycopy_in_heap(src_obj, src_offset_in_bytes, src_raw, dst_obj, dst_offset_in_bytes, dst_raw, length);
501   if (ShenandoahCardBarrier) {
502     bs->write_ref_array((HeapWord*) dst, length);
503   }
504   return result;
505 }
506 
507 template <class T, bool HAS_FWD, bool EVAC, bool ENQUEUE>
508 void ShenandoahBarrierSet::arraycopy_work(T* src, size_t count) {
509   // Young cycles are allowed to run when old marking is in progress. When old marking is in progress,
510   // this barrier will be called with ENQUEUE=true and HAS_FWD=false, even though the young generation
511   // may have forwarded objects.
512   assert(HAS_FWD == _heap->has_forwarded_objects() || _heap->is_concurrent_old_mark_in_progress(), "Forwarded object status is sane");
513   // This function cannot be called to handle marking and evacuation at the same time (they operate on
514   // different sides of the copy).
515   static_assert((HAS_FWD || EVAC) != ENQUEUE, "Cannot evacuate and mark both sides of copy.");
516 
517   Thread* thread = Thread::current();
518   SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
519   ShenandoahMarkingContext* ctx = _heap->marking_context();

522   for (T* elem_ptr = src; elem_ptr < end; elem_ptr++) {
523     T o = RawAccess<>::oop_load(elem_ptr);
524     if (!CompressedOops::is_null(o)) {
525       oop obj = CompressedOops::decode_not_null(o);
526       if (HAS_FWD && cset->is_in(obj)) {
527         oop fwd = ShenandoahForwarding::get_forwardee(obj);
528         if (EVAC && obj == fwd) {
529           fwd = _heap->evacuate_object(obj, thread);
530         }
531         shenandoah_assert_forwarded_except(elem_ptr, obj, _heap->cancelled_gc());
532         ShenandoahHeap::atomic_update_oop(fwd, elem_ptr, o);
533       }
534       if (ENQUEUE && !ctx->is_marked_strong(obj)) {
535         _satb_mark_queue_set.enqueue_known_active(queue, obj);
536       }
537     }
538   }
539 }
540 
541 template <class T>
542 void ShenandoahBarrierSet::arraycopy_barrier(T* src, T* dst, size_t count) {
543   if (count == 0) {
544     // No elements to copy, no need for barrier
545     return;
546   }
547 
548   const char gc_state = ShenandoahThreadLocalData::gc_state(Thread::current());
549   if ((gc_state & ShenandoahHeap::MARKING) != 0) {
550     // If marking old or young, we must evaluate the SATB barrier. This will be the only
551     // action if we are not marking old. If we are marking old, we must still evaluate the
552     // load reference barrier for a young collection.
553     if (_heap->mode()->is_generational()) {
554       arraycopy_marking<true>(dst, count);
555     } else {
556       arraycopy_marking<false>(dst, count);
557     }
558   }
559 
560   if ((gc_state & ShenandoahHeap::EVACUATION) != 0) {
561     assert((gc_state & ShenandoahHeap::YOUNG_MARKING) == 0, "Cannot be marking young during evacuation");
562     arraycopy_evacuation(src, count);
563   } else if ((gc_state & ShenandoahHeap::UPDATE_REFS) != 0) {
564     assert((gc_state & ShenandoahHeap::YOUNG_MARKING) == 0, "Cannot be marking young during update-refs");
565     arraycopy_update(src, count);
566   }
567 }
568 
569 template <bool IS_GENERATIONAL, class T>

470   // Hot code path, called from compiler/runtime. Make sure fast path is fast.
471 
472   // Fix up src before doing the copy, if needed.
473   const char gc_state = ShenandoahThreadLocalData::gc_state(Thread::current());
474   if (gc_state != 0 && ShenandoahCloneBarrier) {
475     ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
476     if ((gc_state & ShenandoahHeap::EVACUATION) != 0) {
477       bs->clone_work<true>(src);
478     } else if ((gc_state & ShenandoahHeap::UPDATE_REFS) != 0) {
479       bs->clone_work<false>(src);
480     }
481   }
482 
483   Raw::clone(src, dst, size);
484 
485   // Current allocator never allocates in old, so clone destination is guaranteed to be in young.
486   // Otherwise we need card barriers.
487   shenandoah_assert_in_young_if(nullptr, dst, ShenandoahCardBarrier);
488 }
489 
490 template <DecoratorSet decorators, typename BarrierSetT>
491 void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::value_copy_in_heap(const ValuePayload& src, const ValuePayload& dst) {
492   precond(src.klass() == dst.klass());
493 
494   const InlineKlass* md = src.klass();
495   if (!md->contains_oops()) {
496     // If we do not have oops in the flat array, we can just do a raw copy.
497     Raw::value_copy(src, dst);
498   } else {
499     ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
500     // addr() points at the payload start, the oop map offset are relative to
501     // the object header, adjust address to account for this discrepancy.
502     const address oop_map_adjusted_src_addr = src.addr() - md->payload_offset();
503     const address oop_map_adjusted_dst_addr = dst.addr() - md->payload_offset();
504     typedef typename ValueOopType<decorators>::type OopType;
505 
506     // Oop maps tell us where the array-like structures are in the value payload.
507     // For simplicity, apply arraycopy barriers over them.
508     bool dest_uninit = HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value;
509     {
510       OopMapBlock* map = md->start_of_nonstatic_oop_maps();
511       OopMapBlock* const end = map + md->nonstatic_oop_map_count();
512 
513       while (map != end) {
514         address src_oop_address = oop_map_adjusted_src_addr + map->offset();
515         address dst_oop_address = oop_map_adjusted_dst_addr + map->offset();
516         bs->arraycopy_barrier((OopType*) src_oop_address, (OopType*) dst_oop_address, map->count(), dest_uninit);
517         map++;
518       }
519     }
520 
521     Raw::value_copy(src, dst);
522 
523     // Similarly, we can ask for ref array store helper for post-barriers.
524     if (ShenandoahCardBarrier) {
525       OopMapBlock* map = md->start_of_nonstatic_oop_maps();
526       OopMapBlock* const end = map + md->nonstatic_oop_map_count();
527       while (map != end) {
528         address dst_oop_address = oop_map_adjusted_dst_addr + map->offset();
529         bs->write_ref_array((HeapWord*) dst_oop_address, map->count());
530         map++;
531       }
532     }
533   }
534 }
535 
536 template <DecoratorSet decorators, typename BarrierSetT>
537 void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::value_store_null_in_heap(const ValuePayload& dst) {
538   const InlineKlass* md = dst.klass();
539   if (!md->contains_oops()) {
540     // If we do not have oops in the flat array, we can just do a raw clear.
541     Raw::value_store_null(dst);
542   } else {
543     ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
544     // addr() points at the payload start, the oop map offset are relative to
545     // the object header, adjust address to account for this discrepancy.
546     const address oop_map_adjusted_dst_addr = dst.addr() - md->payload_offset();
547     typedef typename ValueOopType<decorators>::type OopType;
548 
549     // Oop maps tell us where the array-like structures are in the value payload.
550     // For simplicity, apply arraycopy barriers over them.
551     bool dest_uninit = HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value;
552     if (!dest_uninit) {
553       OopMapBlock* map = md->start_of_nonstatic_oop_maps();
554       OopMapBlock* const end = map + md->nonstatic_oop_map_count();
555       while (map != end) {
556         address dst_oop_address = oop_map_adjusted_dst_addr + map->offset();
557         bs->arraycopy_barrier((OopType*) dst_oop_address, (OopType*) dst_oop_address, map->count(), dest_uninit);
558         map++;
559       }
560     }
561 
562     Raw::value_store_null(dst);
563 
564     // Storing null does not require post-barriers
565   }
566 }
567 
568 template <DecoratorSet decorators, typename BarrierSetT>
569 template <typename T>
570 OopCopyResult ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
571                                                                                                   arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
572                                                                                                   size_t length) {
573   T* src = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw);
574   T* dst = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw);
575   bool dest_uninit = HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value;
576 
577   ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
578   bs->arraycopy_barrier(src, dst, length, dest_uninit);
579   OopCopyResult result = Raw::oop_arraycopy_in_heap(src_obj, src_offset_in_bytes, src_raw, dst_obj, dst_offset_in_bytes, dst_raw, length);
580   if (ShenandoahCardBarrier) {
581     bs->write_ref_array((HeapWord*) dst, length);
582   }
583   return result;
584 }
585 
586 template <class T, bool HAS_FWD, bool EVAC, bool ENQUEUE>
587 void ShenandoahBarrierSet::arraycopy_work(T* src, size_t count) {
588   // Young cycles are allowed to run when old marking is in progress. When old marking is in progress,
589   // this barrier will be called with ENQUEUE=true and HAS_FWD=false, even though the young generation
590   // may have forwarded objects.
591   assert(HAS_FWD == _heap->has_forwarded_objects() || _heap->is_concurrent_old_mark_in_progress(), "Forwarded object status is sane");
592   // This function cannot be called to handle marking and evacuation at the same time (they operate on
593   // different sides of the copy).
594   static_assert((HAS_FWD || EVAC) != ENQUEUE, "Cannot evacuate and mark both sides of copy.");
595 
596   Thread* thread = Thread::current();
597   SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
598   ShenandoahMarkingContext* ctx = _heap->marking_context();

601   for (T* elem_ptr = src; elem_ptr < end; elem_ptr++) {
602     T o = RawAccess<>::oop_load(elem_ptr);
603     if (!CompressedOops::is_null(o)) {
604       oop obj = CompressedOops::decode_not_null(o);
605       if (HAS_FWD && cset->is_in(obj)) {
606         oop fwd = ShenandoahForwarding::get_forwardee(obj);
607         if (EVAC && obj == fwd) {
608           fwd = _heap->evacuate_object(obj, thread);
609         }
610         shenandoah_assert_forwarded_except(elem_ptr, obj, _heap->cancelled_gc());
611         ShenandoahHeap::atomic_update_oop(fwd, elem_ptr, o);
612       }
613       if (ENQUEUE && !ctx->is_marked_strong(obj)) {
614         _satb_mark_queue_set.enqueue_known_active(queue, obj);
615       }
616     }
617   }
618 }
619 
620 template <class T>
621 void ShenandoahBarrierSet::arraycopy_barrier(T* src, T* dst, size_t count, bool dest_uninit) {
622   if (count == 0) {
623     // No elements to copy, no need for barrier
624     return;
625   }
626 
627   const char gc_state = ShenandoahThreadLocalData::gc_state(Thread::current());
628   if (!dest_uninit && (gc_state & ShenandoahHeap::MARKING) != 0) {
629     // If marking old or young, we must evaluate the SATB barrier. This will be the only
630     // action if we are not marking old. If we are marking old, we must still evaluate the
631     // load reference barrier for a young collection.
632     if (_heap->mode()->is_generational()) {
633       arraycopy_marking<true>(dst, count);
634     } else {
635       arraycopy_marking<false>(dst, count);
636     }
637   }
638 
639   if ((gc_state & ShenandoahHeap::EVACUATION) != 0) {
640     assert((gc_state & ShenandoahHeap::YOUNG_MARKING) == 0, "Cannot be marking young during evacuation");
641     arraycopy_evacuation(src, count);
642   } else if ((gc_state & ShenandoahHeap::UPDATE_REFS) != 0) {
643     assert((gc_state & ShenandoahHeap::YOUNG_MARKING) == 0, "Cannot be marking young during update-refs");
644     arraycopy_update(src, count);
645   }
646 }
647 
648 template <bool IS_GENERATIONAL, class T>
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