ladybird/Libraries/LibJS/Runtime/FinalizationRegistry.cpp
Shannon Booth f87041bf3a LibGC+Everywhere: Factor out a LibGC from LibJS
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:

 * JS::NonnullGCPtr -> GC::Ref
 * JS::GCPtr -> GC::Ptr
 * JS::HeapFunction -> GC::Function
 * JS::CellImpl -> GC::Cell
 * JS::Handle -> GC::Root
2024-11-15 14:49:20 +01:00

105 lines
3.5 KiB
C++

/*
* Copyright (c) 2021-2022, Idan Horowitz <idan.horowitz@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/FinalizationRegistry.h>
namespace JS {
GC_DEFINE_ALLOCATOR(FinalizationRegistry);
FinalizationRegistry::FinalizationRegistry(Realm& realm, GC::Ref<JobCallback> cleanup_callback, Object& prototype)
: Object(ConstructWithPrototypeTag::Tag, prototype)
, WeakContainer(heap())
, m_realm(realm)
, m_cleanup_callback(cleanup_callback)
{
}
void FinalizationRegistry::add_finalization_record(Cell& target, Value held_value, Cell* unregister_token)
{
VERIFY(!held_value.is_empty());
m_records.append({ &target, held_value, unregister_token });
}
// Extracted from FinalizationRegistry.prototype.unregister ( unregisterToken )
bool FinalizationRegistry::remove_by_token(Cell& unregister_token)
{
// 4. Let removed be false.
auto removed = false;
// 5. For each Record { [[WeakRefTarget]], [[HeldValue]], [[UnregisterToken]] } cell of finalizationRegistry.[[Cells]], do
for (auto it = m_records.begin(); it != m_records.end(); ++it) {
// a. If cell.[[UnregisterToken]] is not empty and SameValue(cell.[[UnregisterToken]], unregisterToken) is true, then
if (it->unregister_token == &unregister_token) {
// i. Remove cell from finalizationRegistry.[[Cells]].
it.remove(m_records);
// ii. Set removed to true.
removed = true;
}
}
// 6. Return removed.
return removed;
}
void FinalizationRegistry::remove_dead_cells(Badge<GC::Heap>)
{
auto any_cells_were_removed = false;
for (auto& record : m_records) {
if (!record.target || record.target->state() == Cell::State::Live)
continue;
record.target = nullptr;
any_cells_were_removed = true;
break;
}
if (any_cells_were_removed)
vm().host_enqueue_finalization_registry_cleanup_job(*this);
}
// 9.13 CleanupFinalizationRegistry ( finalizationRegistry ), https://tc39.es/ecma262/#sec-cleanup-finalization-registry
ThrowCompletionOr<void> FinalizationRegistry::cleanup(GC::Ptr<JobCallback> callback)
{
auto& vm = this->vm();
// 1. Assert: finalizationRegistry has [[Cells]] and [[CleanupCallback]] internal slots.
// Note: Ensured by type.
// 2. Let callback be finalizationRegistry.[[CleanupCallback]].
auto cleanup_callback = callback ? callback : m_cleanup_callback;
// 3. While finalizationRegistry.[[Cells]] contains a Record cell such that cell.[[WeakRefTarget]] is empty, an implementation may perform the following steps:
for (auto it = m_records.begin(); it != m_records.end(); ++it) {
// a. Choose any such cell.
if (it->target != nullptr)
continue;
// b. Remove cell from finalizationRegistry.[[Cells]].
GC::MarkedVector<Value> arguments(vm.heap());
arguments.append(it->held_value);
it.remove(m_records);
// c. Perform ? HostCallJobCallback(callback, undefined, « cell.[[HeldValue]] »).
TRY(vm.host_call_job_callback(*cleanup_callback, js_undefined(), move(arguments)));
}
// 4. Return unused.
return {};
}
void FinalizationRegistry::visit_edges(Cell::Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(m_realm);
visitor.visit(m_cleanup_callback);
for (auto& record : m_records) {
visitor.visit(record.held_value);
visitor.visit(record.unregister_token);
}
}
}