50 lines
1.2 KiB
C++
50 lines
1.2 KiB
C++
/*
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* Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <LibJS/Runtime/WeakRef.h>
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namespace JS {
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WeakRef* WeakRef::create(GlobalObject& global_object, Object* object)
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{
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return global_object.heap().allocate<WeakRef>(global_object, object, *global_object.weak_ref_prototype());
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}
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WeakRef::WeakRef(Object* object, Object& prototype)
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: Object(prototype)
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, WeakContainer(heap())
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, m_value(object)
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, m_last_execution_generation(vm().execution_generation())
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{
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}
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WeakRef::~WeakRef()
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{
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}
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void WeakRef::remove_swept_cells(Badge<Heap>, Vector<Cell*>& cells)
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{
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VERIFY(m_value);
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for (auto* cell : cells) {
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if (m_value != cell)
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continue;
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m_value = nullptr;
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// This is an optimization, we deregister from the garbage collector early (even if we were not garbage collected ourself yet)
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// to reduce the garbage collection overhead, which we can do because a cleared weak ref cannot be reused.
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WeakContainer::deregister();
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break;
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}
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}
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void WeakRef::visit_edges(Visitor& visitor)
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{
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Object::visit_edges(visitor);
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if (vm().execution_generation() == m_last_execution_generation)
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visitor.visit(m_value);
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}
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}
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