// Copyright 2020 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 INCLUDE_CPPGC_EPHEMERON_PAIR_H_ #define INCLUDE_CPPGC_EPHEMERON_PAIR_H_ #include "cppgc/liveness-broker.h" #include "cppgc/member.h" namespace cppgc { /** * An ephemeron pair is used to conditionally retain an object. * The `value` will be kept alive only if the `key` is alive. */ template <typename K, typename V> struct EphemeronPair { EphemeronPair(K* k, V* v) : key(k), value(v) {} WeakMember<K> key; Member<V> value; void ClearValueIfKeyIsDead(const LivenessBroker& broker) { if (!broker.IsHeapObjectAlive(key)) value = nullptr; } }; } // namespace cppgc #endif // INCLUDE_CPPGC_EPHEMERON_PAIR_H_