d00b79568f
https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#cother-other-default-operation-rules "The compiler is more likely to get the default semantics right and you cannot implement these functions better than the compiler."
44 lines
1.1 KiB
C++
44 lines
1.1 KiB
C++
/*
|
|
* Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <LibJS/Runtime/WeakRef.h>
|
|
|
|
namespace JS {
|
|
|
|
WeakRef* WeakRef::create(GlobalObject& global_object, Object* object)
|
|
{
|
|
return global_object.heap().allocate<WeakRef>(global_object, object, *global_object.weak_ref_prototype());
|
|
}
|
|
|
|
WeakRef::WeakRef(Object* object, Object& prototype)
|
|
: Object(prototype)
|
|
, WeakContainer(heap())
|
|
, m_value(object)
|
|
, m_last_execution_generation(vm().execution_generation())
|
|
{
|
|
}
|
|
|
|
void WeakRef::remove_dead_cells(Badge<Heap>)
|
|
{
|
|
VERIFY(m_value);
|
|
if (m_value->state() == Cell::State::Live)
|
|
return;
|
|
|
|
m_value = nullptr;
|
|
// This is an optimization, we deregister from the garbage collector early (even if we were not garbage collected ourself yet)
|
|
// to reduce the garbage collection overhead, which we can do because a cleared weak ref cannot be reused.
|
|
WeakContainer::deregister();
|
|
}
|
|
|
|
void WeakRef::visit_edges(Visitor& visitor)
|
|
{
|
|
Base::visit_edges(visitor);
|
|
|
|
if (vm().execution_generation() == m_last_execution_generation)
|
|
visitor.visit(m_value);
|
|
}
|
|
|
|
}
|