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// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_OBJECTS_JS_WEAK_REFS_INL_H_
#define V8_OBJECTS_JS_WEAK_REFS_INL_H_
#include "src/objects/js-weak-refs.h"
#include "src/api-inl.h"
#include "src/heap/heap-write-barrier-inl.h"
#include "src/objects/microtask-inl.h"
#include "src/objects/smi-inl.h"
// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"
namespace v8 {
namespace internal {
OBJECT_CONSTRUCTORS_IMPL(JSWeakCell, JSObject)
OBJECT_CONSTRUCTORS_IMPL(JSWeakRef, JSObject)
OBJECT_CONSTRUCTORS_IMPL(JSWeakFactory, JSObject)
OBJECT_CONSTRUCTORS_IMPL(JSWeakFactoryCleanupIterator, JSObject)
OBJECT_CONSTRUCTORS_IMPL(WeakFactoryCleanupJobTask, Microtask)
ACCESSORS(JSWeakFactory, native_context, NativeContext, kNativeContextOffset)
ACCESSORS(JSWeakFactory, cleanup, Object, kCleanupOffset)
ACCESSORS(JSWeakFactory, active_cells, Object, kActiveCellsOffset)
ACCESSORS(JSWeakFactory, cleared_cells, Object, kClearedCellsOffset)
SMI_ACCESSORS(JSWeakFactory, flags, kFlagsOffset)
ACCESSORS(JSWeakFactory, next, Object, kNextOffset)
CAST_ACCESSOR(JSWeakFactory)
ACCESSORS(JSWeakCell, factory, Object, kFactoryOffset)
ACCESSORS(JSWeakCell, target, Object, kTargetOffset)
ACCESSORS(JSWeakCell, holdings, Object, kHoldingsOffset)
ACCESSORS(JSWeakCell, next, Object, kNextOffset)
ACCESSORS(JSWeakCell, prev, Object, kPrevOffset)
CAST_ACCESSOR(JSWeakCell)
CAST_ACCESSOR(JSWeakRef)
ACCESSORS(JSWeakRef, target, Object, kTargetOffset)
ACCESSORS(JSWeakFactoryCleanupIterator, factory, JSWeakFactory, kFactoryOffset)
CAST_ACCESSOR(JSWeakFactoryCleanupIterator)
ACCESSORS(WeakFactoryCleanupJobTask, factory, JSWeakFactory, kFactoryOffset)
CAST_ACCESSOR(WeakFactoryCleanupJobTask)
void JSWeakFactory::AddWeakCell(JSWeakCell weak_cell) {
weak_cell->set_factory(*this);
weak_cell->set_next(active_cells());
if (active_cells()->IsJSWeakCell()) {
JSWeakCell::cast(active_cells())->set_prev(weak_cell);
}
set_active_cells(weak_cell);
}
bool JSWeakFactory::NeedsCleanup() const {
return cleared_cells()->IsJSWeakCell();
}
bool JSWeakFactory::scheduled_for_cleanup() const {
return ScheduledForCleanupField::decode(flags());
}
void JSWeakFactory::set_scheduled_for_cleanup(bool scheduled_for_cleanup) {
set_flags(ScheduledForCleanupField::update(flags(), scheduled_for_cleanup));
}
JSWeakCell JSWeakFactory::PopClearedCell(Isolate* isolate) {
JSWeakCell weak_cell = JSWeakCell::cast(cleared_cells());
DCHECK(weak_cell->prev()->IsUndefined(isolate));
set_cleared_cells(weak_cell->next());
weak_cell->set_next(ReadOnlyRoots(isolate).undefined_value());
if (cleared_cells()->IsJSWeakCell()) {
JSWeakCell cleared_cells_head = JSWeakCell::cast(cleared_cells());
DCHECK_EQ(cleared_cells_head->prev(), weak_cell);
cleared_cells_head->set_prev(ReadOnlyRoots(isolate).undefined_value());
} else {
DCHECK(cleared_cells()->IsUndefined(isolate));
}
return weak_cell;
}
void JSWeakCell::Nullify(
Isolate* isolate,
std::function<void(HeapObject object, ObjectSlot slot, Object target)>
gc_notify_updated_slot) {
DCHECK(target()->IsJSReceiver());
set_target(ReadOnlyRoots(isolate).undefined_value());
JSWeakFactory weak_factory = JSWeakFactory::cast(factory());
// Remove from the JSWeakCell from the "active_cells" list of its
// JSWeakFactory and insert it into the "cleared" list.
if (prev()->IsJSWeakCell()) {
DCHECK_NE(weak_factory->active_cells(), *this);
JSWeakCell prev_cell = JSWeakCell::cast(prev());
prev_cell->set_next(next());
gc_notify_updated_slot(prev_cell,
prev_cell.RawField(JSWeakCell::kNextOffset), next());
} else {
DCHECK_EQ(weak_factory->active_cells(), *this);
weak_factory->set_active_cells(next());
gc_notify_updated_slot(
weak_factory, weak_factory.RawField(JSWeakFactory::kActiveCellsOffset),
next());
}
if (next()->IsJSWeakCell()) {
JSWeakCell next_cell = JSWeakCell::cast(next());
next_cell->set_prev(prev());
gc_notify_updated_slot(next_cell,
next_cell.RawField(JSWeakCell::kPrevOffset), prev());
}
set_prev(ReadOnlyRoots(isolate).undefined_value());
Object cleared_head = weak_factory->cleared_cells();
if (cleared_head->IsJSWeakCell()) {
JSWeakCell cleared_head_cell = JSWeakCell::cast(cleared_head);
cleared_head_cell->set_prev(*this);
gc_notify_updated_slot(cleared_head_cell,
cleared_head_cell.RawField(JSWeakCell::kPrevOffset),
*this);
}
set_next(weak_factory->cleared_cells());
gc_notify_updated_slot(*this, RawField(JSWeakCell::kNextOffset), next());
weak_factory->set_cleared_cells(*this);
gc_notify_updated_slot(
weak_factory, weak_factory.RawField(JSWeakFactory::kClearedCellsOffset),
*this);
}
void JSWeakCell::Clear(Isolate* isolate) {
// Unlink the JSWeakCell from the list it's in (if any). The JSWeakCell can be
// in its JSWeakFactory's active_cells list, cleared_cells list or neither (if
// it has been already taken out).
DCHECK(target()->IsUndefined() || target()->IsJSReceiver());
set_target(ReadOnlyRoots(isolate).undefined_value());
if (factory()->IsJSWeakFactory()) {
JSWeakFactory weak_factory = JSWeakFactory::cast(factory());
if (weak_factory->active_cells() == *this) {
DCHECK(!prev()->IsJSWeakCell());
weak_factory->set_active_cells(next());
} else if (weak_factory->cleared_cells() == *this) {
DCHECK(!prev()->IsJSWeakCell());
weak_factory->set_cleared_cells(next());
} else if (prev()->IsJSWeakCell()) {
JSWeakCell prev_cell = JSWeakCell::cast(prev());
prev_cell->set_next(next());
}
if (next()->IsJSWeakCell()) {
JSWeakCell next_cell = JSWeakCell::cast(next());
next_cell->set_prev(prev());
}
set_prev(ReadOnlyRoots(isolate).undefined_value());
set_next(ReadOnlyRoots(isolate).undefined_value());
set_holdings(ReadOnlyRoots(isolate).undefined_value());
set_factory(ReadOnlyRoots(isolate).undefined_value());
} else {
// Already cleared.
DCHECK(next()->IsUndefined(isolate));
DCHECK(prev()->IsUndefined(isolate));
DCHECK(holdings()->IsUndefined(isolate));
DCHECK(factory()->IsUndefined(isolate));
}
}
} // namespace internal
} // namespace v8
#include "src/objects/object-macros-undef.h"
#endif // V8_OBJECTS_JS_WEAK_REFS_INL_H_
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