cef/libcef_dll/base/cef_weak_ptr.cc

72 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 "include/base/cef_weak_ptr.h"
namespace base {
namespace cef_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 thread.
thread_checker_.DetachFromThread();
}
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())
<< "WeakPtrs must be invalidated on the same thread.";
is_valid_ = false;
}
bool WeakReference::Flag::IsValid() const {
DCHECK(thread_checker_.CalledOnValidThread())
<< "WeakPtrs must be checked on the same 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 cef_internal
} // namespace base