blob: 9dec8fd6db9c29956673a79326efa4b22af2f3ad [file] [log] [blame]
// 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() : is_valid_(true) {
}
void WeakReference::Flag::Invalidate() {
// The flag being invalidated with a single ref implies that there are no
// weak pointers in existence. Allow deletion on other thread in this case.
DCHECK(thread_checker_.CalledOnValidThread() || HasOneRef());
is_valid_ = false;
}
bool WeakReference::Flag::IsValid() const {
DCHECK(thread_checker_.CalledOnValidThread());
return is_valid_;
}
WeakReference::Flag::~Flag() {
}
WeakReference::WeakReference() {
}
WeakReference::WeakReference(const Flag* flag) : flag_(flag) {
}
WeakReference::~WeakReference() {
}
bool WeakReference::is_valid() const {
return flag_ && flag_->IsValid();
}
WeakReferenceOwner::WeakReferenceOwner() {
}
WeakReferenceOwner::~WeakReferenceOwner() {
Invalidate();
}
WeakReference WeakReferenceOwner::GetRef() const {
// We also want to reattach to the current thread if all previous references
// have gone away.
if (!HasRefs())
flag_ = new WeakReference::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