// Copyright (c) 2011 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "base/memory/weak_ptr.h" namespace base { namespace internal { WeakReference::Flag::Flag(Flag** handle) : handle_(handle) { } void WeakReference::Flag::Invalidate() { DCHECK(thread_checker_.CalledOnValidThread()); handle_ = NULL; } bool WeakReference::Flag::IsValid() const { DCHECK(thread_checker_.CalledOnValidThread()); return handle_ != NULL; } WeakReference::Flag::~Flag() { if (handle_) *handle_ = NULL; } WeakReference::WeakReference() { } WeakReference::WeakReference(Flag* flag) : flag_(flag) { } WeakReference::~WeakReference() { } bool WeakReference::is_valid() const { return flag_ && flag_->IsValid(); } WeakReferenceOwner::WeakReferenceOwner() : flag_(NULL) { } WeakReferenceOwner::~WeakReferenceOwner() { Invalidate(); } WeakReference WeakReferenceOwner::GetRef() const { if (!flag_) flag_ = new WeakReference::Flag(&flag_); return WeakReference(flag_); } void WeakReferenceOwner::Invalidate() { if (flag_) { flag_->Invalidate(); flag_ = NULL; } } WeakPtrBase::WeakPtrBase() { } WeakPtrBase::~WeakPtrBase() { } WeakPtrBase::WeakPtrBase(const WeakReference& ref) : ref_(ref) { } } // namespace internal } // namespace base