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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#ifndef mozilla_dom_NodeOwnedObjectList_h
#define mozilla_dom_NodeOwnedObjectList_h
#include <concepts>
#include "MainThreadUtils.h"
#include "mozilla/DoublyLinkedList.h"
namespace mozilla::dom {
template <typename T>
concept NodeOwnedObjectListEntry =
std::derived_from<T, DoublyLinkedListElement<T>> &&
requires(const T& aEntry, T& aMutableEntry) {
{ aEntry.HasOwnerInCCGenerationDocument() } -> std::same_as<bool>;
aMutableEntry.MarkForCC();
};
// Main thread list of objects which nodes keep alive. An object owned by a node
// in a document marked uncollectable for the current CC generation is alive
// too, so unmarking its gray JS lets the cycle collector skip whatever is kept
// alive only through that JS.
template <NodeOwnedObjectListEntry T>
class NodeOwnedObjectList final {
public:
static void Add(T* aEntry) {
MOZ_ASSERT(NS_IsMainThread());
sEntries.pushBack(aEntry);
}
static void Remove(T* aEntry) {
MOZ_ASSERT(NS_IsMainThread());
// Destructors pass here entries which are not in the list.
if (sEntries.ElementProbablyInList(aEntry)) {
sEntries.remove(aEntry);
}
}
static bool IsEmpty() { return sEntries.isEmpty(); }
static void UnmarkGrayInCCGenerationDocuments() {
for (T& entry : sEntries) {
if (entry.HasOwnerInCCGenerationDocument()) {
entry.MarkForCC();
}
}
}
private:
static constinit inline DoublyLinkedList<T> sEntries;
};
} // namespace mozilla::dom
#endif // mozilla_dom_NodeOwnedObjectList_h