dart::ScavengerVisitorBase< parallel > Class Template Reference

Inheritance diagram for dart::ScavengerVisitorBase< parallel >:

Public Member Functions
	ScavengerVisitorBase (IsolateGroup *isolate_group, Scavenger *scavenger, SemiSpace *from, FreeList *freelist, PromotionStack *promotion_stack)
	~ScavengerVisitorBase ()
void	VisitTypedDataViewPointers (TypedDataViewPtr view, CompressedObjectPtr *first, CompressedObjectPtr *last) override
void	VisitPointers (ObjectPtr *first, ObjectPtr *last) override
void	VisitingOldObject (ObjectPtr obj)
DART_FORCE_INLINE intptr_t	ProcessObject (ObjectPtr obj)
intptr_t	bytes_promoted () const
void	ProcessRoots ()
void	ProcessSurvivors ()
void	ProcessAll ()
void	ProcessWeakProperties ()
bool	HasWork ()
bool	WaitForWork (RelaxedAtomic< uintptr_t > *num_busy)
void	ProcessWeak ()
void	Finalize ()
Page *	head () const
Page *	tail () const
Public Member Functions inherited from dart::ObjectPointerVisitor
	ObjectPointerVisitor (IsolateGroup *isolate_group)
virtual	~ObjectPointerVisitor ()
IsolateGroup *	isolate_group () const
void	VisitCompressedPointers (uword heap_base, CompressedObjectPtr *first, CompressedObjectPtr *last)
void	VisitPointers (ObjectPtr *p, intptr_t len)
void	VisitPointer (ObjectPtr *p)
const char *	gc_root_type () const
void	set_gc_root_type (const char *gc_root_type)
void	clear_gc_root_type ()
virtual bool	visit_weak_persistent_handles () const
virtual bool	trace_values_through_fields () const
const ClassTable *	class_table () const
virtual bool	CanVisitSuspendStatePointers (SuspendStatePtr suspend_state)

Static Public Member Functions
static bool	ForwardOrSetNullIfCollected (ObjectPtr parent, CompressedObjectPtr *ptr_address)

Detailed Description

template<bool parallel>
class dart::ScavengerVisitorBase< parallel >

Definition at line 130 of file scavenger.cc.

Constructor & Destructor Documentation

ScavengerVisitorBase()

template<bool parallel>

dart::ScavengerVisitorBase< parallel >::ScavengerVisitorBase ( IsolateGroup *  isolate_group, Scavenger *  scavenger, SemiSpace *  from, FreeList *  freelist, PromotionStack *  promotion_stack  )

inlineexplicit

Definition at line 132 of file scavenger.cc.

      : ObjectPointerVisitor(isolate_group),
        thread_(nullptr),
        scavenger_(scavenger),
        from_(from),
        page_space_(scavenger->heap_->old_space()),
        freelist_(freelist),
        bytes_promoted_(0),
        visiting_old_object_(nullptr),
        promoted_list_(promotion_stack) {}

~ScavengerVisitorBase()

template<bool parallel>

dart::ScavengerVisitorBase< parallel >::~ScavengerVisitorBase ( )

inline

Definition at line 146 of file scavenger.cc.

{}

Member Function Documentation

bytes_promoted()

template<bool parallel>

intptr_t dart::ScavengerVisitorBase< parallel >::bytes_promoted ( ) const

inline

Definition at line 251 of file scavenger.cc.

{ return bytes_promoted_; }

Finalize()

template<bool parallel>

void dart::ScavengerVisitorBase< parallel >::Finalize ( )

inline

Definition at line 332 of file scavenger.cc.

                  {
    if (!scavenger_->abort_) {
      promoted_list_.Finalize();
      weak_array_list_.Finalize();
      weak_property_list_.Finalize();
      weak_reference_list_.Finalize();
      finalizer_entry_list_.Finalize();
    } else {
      promoted_list_.AbandonWork();
      weak_array_list_.AbandonWork();
      weak_property_list_.AbandonWork();
      weak_reference_list_.AbandonWork();
      finalizer_entry_list_.AbandonWork();
    }
  }

ForwardOrSetNullIfCollected()

template<bool parallel>

bool dart::ScavengerVisitorBase< parallel >::ForwardOrSetNullIfCollected ( ObjectPtr  parent, CompressedObjectPtr *  ptr_address  )

static

Definition at line 1578 of file scavenger.cc.

                               {
  ObjectPtr target = slot->Decompress(parent->heap_base());
  if (target->IsImmediateOrOldObject()) {
    // Object already null (which is old) or not touched during this GC.
    return false;
  }
  uword header = ReadHeaderRelaxed(target);
  if (IsForwarding(header)) {
    // Get the new location of the object.
    target = ForwardedObj(header);
    *slot = target;
    if (target->IsNewObject() && parent->IsOldObject() &&
        parent->untag()->TryAcquireRememberedBit()) {
      Thread::Current()->StoreBufferAddObjectGC(parent);
    }
    return false;
  }
  ASSERT(target->IsHeapObject());
  ASSERT(target->IsNewObject());
  *slot = Object::null();
  return true;
}

HasWork()

template<bool parallel>

bool dart::ScavengerVisitorBase< parallel >::HasWork ( )

inline

Definition at line 303 of file scavenger.cc.

                 {
    if (scavenger_->abort_) return false;
    return (scan_ != tail_) || (scan_ != nullptr && !scan_->IsResolved()) ||
           !promoted_list_.IsEmpty();
  }

head()

template<bool parallel>

Page * dart::ScavengerVisitorBase< parallel >::head ( ) const

inline

Definition at line 348 of file scavenger.cc.

{ return head_; }

ProcessAll()

template<bool parallel>

void dart::ScavengerVisitorBase< parallel >::ProcessAll ( )

inline

Definition at line 278 of file scavenger.cc.

                    {
    TIMELINE_FUNCTION_GC_DURATION(thread_, "ProcessToSpace");
    LongJumpScope jump(thread_);
    if (setjmp(*jump.Set()) == 0) {
      do {
        do {
          ProcessToSpace();
          ProcessPromotedList();
        } while (HasWork());
        ProcessWeakPropertiesScoped();
      } while (HasWork());
    } else {
      ASSERT(scavenger_->abort_);
    }
  }

ProcessObject()

template<bool parallel>

intptr_t dart::ScavengerVisitorBase< parallel >::ProcessObject

(

ObjectPtr

obj

)

Definition at line 1348 of file scavenger.cc.

                                                                    {
#if defined(DEBUG)
  if (obj->IsNewObject()) {
    ASSERT(visiting_old_object_ == nullptr);
  } else {
    ASSERT(visiting_old_object_ == obj);
    ASSERT(!obj->untag()->IsRemembered());
  }
#endif
 
  intptr_t cid = obj->GetClassId();
  if (UNLIKELY(cid == kWeakPropertyCid)) {
    WeakPropertyPtr weak_property = static_cast<WeakPropertyPtr>(obj);
    if (!IsScavengeSurvivor(weak_property->untag()->key())) {
      weak_property_list_.Push(weak_property);
      return WeakProperty::InstanceSize();
    }
  } else if (UNLIKELY(cid == kWeakReferenceCid)) {
    WeakReferencePtr weak_reference = static_cast<WeakReferencePtr>(obj);
    if (!IsScavengeSurvivor(weak_reference->untag()->target())) {
#if !defined(DART_COMPRESSED_POINTERS)
      ScavengePointer(&weak_reference->untag()->type_arguments_);
#else
      ScavengeCompressedPointer(weak_reference->heap_base(),
                                &weak_reference->untag()->type_arguments_);
#endif
      weak_reference_list_.Push(weak_reference);
      return WeakReference::InstanceSize();
    }
  } else if (UNLIKELY(cid == kWeakArrayCid)) {
    WeakArrayPtr weak_array = static_cast<WeakArrayPtr>(obj);
    weak_array_list_.Push(weak_array);
    return WeakArray::InstanceSize(Smi::Value(weak_array->untag()->length()));
  } else if (UNLIKELY(cid == kFinalizerEntryCid)) {
    FinalizerEntryPtr finalizer_entry = static_cast<FinalizerEntryPtr>(obj);
#if !defined(DART_COMPRESSED_POINTERS)
    ScavengePointer(&finalizer_entry->untag()->token_);
    ScavengePointer(&finalizer_entry->untag()->next_);
#else
    ScavengeCompressedPointer(finalizer_entry->heap_base(),
                              &finalizer_entry->untag()->token_);
    ScavengeCompressedPointer(finalizer_entry->heap_base(),
                              &finalizer_entry->untag()->next_);
#endif
    finalizer_entry_list_.Push(finalizer_entry);
    return FinalizerEntry::InstanceSize();
  }
  return obj->untag()->VisitPointersNonvirtual(this);
}

ProcessRoots()

template<bool parallel>

void dart::ScavengerVisitorBase< parallel >::ProcessRoots ( )

inline

Definition at line 253 of file scavenger.cc.

                      {
    thread_ = Thread::Current();
    page_space_->AcquireLock(freelist_);
 
    LongJumpScope jump(thread_);
    if (setjmp(*jump.Set()) == 0) {
      scavenger_->IterateRoots(this);
    } else {
      ASSERT(scavenger_->abort_);
    }
  }

ProcessSurvivors()

template<bool parallel>

void dart::ScavengerVisitorBase< parallel >::ProcessSurvivors ( )

inline

Definition at line 265 of file scavenger.cc.

                          {
    LongJumpScope jump(thread_);
    if (setjmp(*jump.Set()) == 0) {
      // Iterate until all work has been drained.
      do {
        ProcessToSpace();
        ProcessPromotedList();
      } while (HasWork());
    } else {
      ASSERT(scavenger_->abort_);
    }
  }

ProcessWeak()

template<bool parallel>

void dart::ScavengerVisitorBase< parallel >::ProcessWeak ( )

inline

Definition at line 313 of file scavenger.cc.

                     {
    if (!scavenger_->abort_) {
      ASSERT(!HasWork());
 
      for (Page* page = head_; page != nullptr; page = page->next()) {
        ASSERT(page->IsResolved());
        page->RecordSurvivors();
      }
 
      MournWeakProperties();
      MournWeakReferences();
      MournWeakArrays();
      MournFinalizerEntries();
      scavenger_->IterateWeak();
    }
    page_space_->ReleaseLock(freelist_);
    thread_ = nullptr;
  }

ProcessWeakProperties()

template<bool parallel>

void dart::ScavengerVisitorBase< parallel >::ProcessWeakProperties ( )

inline

Definition at line 294 of file scavenger.cc.

                               {
    LongJumpScope jump(thread_);
    if (setjmp(*jump.Set()) == 0) {
      ProcessWeakPropertiesScoped();
    } else {
      ASSERT(scavenger_->abort_);
    }
  }

tail()

template<bool parallel>

Page * dart::ScavengerVisitorBase< parallel >::tail ( ) const

inline

Definition at line 349 of file scavenger.cc.

{ return tail_; }

VisitingOldObject()

template<bool parallel>

void dart::ScavengerVisitorBase< parallel >::VisitingOldObject ( ObjectPtr  obj )

inline

Definition at line 241 of file scavenger.cc.

                                        {
    ASSERT((obj == nullptr) || obj->IsOldObject());
    visiting_old_object_ = obj;
    if (obj != nullptr) {
      // Card update happens in Page::VisitRememberedCards.
      ASSERT(!obj->untag()->IsCardRemembered());
    }
  }

VisitPointers()

template<bool parallel>

void dart::ScavengerVisitorBase< parallel >::VisitPointers ( ObjectPtr *  first, ObjectPtr *  last  )

inlineoverridevirtual

Implements dart::ObjectPointerVisitor.

Definition at line 221 of file scavenger.cc.

                                                                 {
    ASSERT(Utils::IsAligned(first, sizeof(*first)));
    ASSERT(Utils::IsAligned(last, sizeof(*last)));
    for (ObjectPtr* current = first; current <= last; current++) {
      ScavengePointer(current);
    }
  }

VisitTypedDataViewPointers()

template<bool parallel>

void dart::ScavengerVisitorBase< parallel >::VisitTypedDataViewPointers ( TypedDataViewPtr  view, CompressedObjectPtr *  first, CompressedObjectPtr *  last  )

inlineoverridevirtual

Reimplemented from dart::ObjectPointerVisitor.

Definition at line 152 of file scavenger.cc.

                                                                      {
    // TypedDataViews require extra processing to update their
    // PointerBase::data_ pointer. If the underlying typed data is external, no
    // update is needed. If the underlying typed data is internal, the pointer
    // must be updated if the typed data was copied or promoted. We cannot
    // safely dereference the underlying typed data to make this distinction.
    // It may have been forwarded by a different scavenger worker, so the access
    // could have a data race. Rather than checking the CID of the underlying
    // typed data, which requires dereferencing the copied/promoted header, we
    // compare the view's internal pointer to what it should be if the
    // underlying typed data was internal, and assume that external typed data
    // never points into the Dart heap. We must do this before VisitPointers
    // because we want to compare the old pointer and old typed data.
    const bool is_external =
        view->untag()->data_ != view->untag()->DataFieldForInternalTypedData();
 
    // Forward all fields of the typed data view.
    VisitCompressedPointers(view->heap_base(), first, last);
 
    if (view->untag()->data_ == nullptr) {
      ASSERT(RawSmiValue(view->untag()->offset_in_bytes()) == 0 &&
             RawSmiValue(view->untag()->length()) == 0);
      ASSERT(is_external);
      return;
    }
 
    // Explicit ifdefs because the compiler does not eliminate the unused
    // relaxed load.
#if defined(DEBUG)
    // Validate 'this' is a typed data view.
    const uword view_header = ReadHeaderRelaxed(view);
    ASSERT(!IsForwarding(view_header) || view->IsOldObject());
    ASSERT(IsTypedDataViewClassId(view->GetClassIdMayBeSmi()) ||
           IsUnmodifiableTypedDataViewClassId(view->GetClassIdMayBeSmi()));
 
    // Validate that the backing store is not a forwarding word. There is a data
    // race reader the backing store's header unless there is only one worker.
    TypedDataBasePtr td = view->untag()->typed_data();
    ASSERT(td->IsHeapObject());
    if (!parallel) {
      const uword td_header = ReadHeaderRelaxed(td);
      ASSERT(!IsForwarding(td_header) || td->IsOldObject());
      if (td != Object::null()) {
        // Fast object copy temporarily stores null in the typed_data field of
        // views. This can cause the RecomputeDataFieldForInternalTypedData to
        // run inappropriately, but when the object copy continues it will fix
        // the data_ pointer.
        ASSERT_EQUAL(IsExternalTypedDataClassId(td->GetClassId()), is_external);
      }
    }
#endif
 
    // If we have external typed data we can simply return since the backing
    // store lives in C-heap and will not move.
    if (is_external) {
      return;
    }
 
    // Now we update the inner pointer.
#if defined(DEBUG)
    if (!parallel) {
      ASSERT(IsTypedDataClassId(td->GetClassId()));
    }
#endif
    view->untag()->RecomputeDataFieldForInternalTypedData();
  }

WaitForWork()

template<bool parallel>

bool dart::ScavengerVisitorBase< parallel >::WaitForWork ( RelaxedAtomic< uintptr_t > *  num_busy )

inline

Definition at line 309 of file scavenger.cc.

                                                       {
    return promoted_list_.WaitForWork(num_busy, scavenger_->abort_);
  }

---

The documentation for this class was generated from the following file:

• third_party/dart-lang/sdk/runtime/vm/heap/scavenger.cc