78 lines
1.9 KiB
C++
78 lines
1.9 KiB
C++
|
// 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) {
|
||
|
|
// Flags only become bound when checked for validity, or invalidated,
|
||
|
|
// so that we can check that later validity/invalidation operations on
|
||
|
|
// the same Flag take place on the same sequenced thread.
|
||
|
|
sequence_checker_.DetachFromSequence();
|
||
|
|
}
|
||
|
|
|
||
|
|
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(sequence_checker_.CalledOnValidSequencedThread() || HasOneRef())
|
||
|
|
<< "WeakPtrs must be invalidated on the same sequenced thread.";
|
||
|
|
is_valid_ = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
bool WeakReference::Flag::IsValid() const {
|
||
|
|
DCHECK(sequence_checker_.CalledOnValidSequencedThread())
|
||
|
|
<< "WeakPtrs must be checked on the same sequenced thread.";
|
||
|
|
return is_valid_;
|
||
|
|
}
|
||
|
|
|
||
|
|
WeakReference::Flag::~Flag() {
|
||
|
|
}
|
||
|
|
|
||
|
|
WeakReference::WeakReference() {
|
||
|
|
}
|
||
|
|
|
||
|
|
WeakReference::WeakReference(const Flag* flag) : flag_(flag) {
|
||
|
|
}
|
||
|
|
|
||
|
|
WeakReference::~WeakReference() {
|
||
|
|
}
|
||
|
|
|
||
|
|
bool WeakReference::is_valid() const { return flag_.get() && flag_->IsValid(); }
|
||
|
|
|
||
|
|
WeakReferenceOwner::WeakReferenceOwner() {
|
||
|
|
}
|
||
|
|
|
||
|
|
WeakReferenceOwner::~WeakReferenceOwner() {
|
||
|
|
Invalidate();
|
||
|
|
}
|
||
|
|
|
||
|
|
WeakReference WeakReferenceOwner::GetRef() const {
|
||
|
|
// If we hold the last reference to the Flag then create a new one.
|
||
|
|
if (!HasRefs())
|
||
|
|
flag_ = new WeakReference::Flag();
|
||
|
|
|
||
|
|
return WeakReference(flag_.get());
|
||
|
|
}
|
||
|
|
|
||
|
|
void WeakReferenceOwner::Invalidate() {
|
||
|
|
if (flag_.get()) {
|
||
|
|
flag_->Invalidate();
|
||
|
|
flag_ = NULL;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
WeakPtrBase::WeakPtrBase() {
|
||
|
|
}
|
||
|
|
|
||
|
|
WeakPtrBase::~WeakPtrBase() {
|
||
|
|
}
|
||
|
|
|
||
|
|
WeakPtrBase::WeakPtrBase(const WeakReference& ref) : ref_(ref) {
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace internal
|
||
|
|
} // namespace base
|