gecko-dev/ipc/mscom/Aggregation.h

52 строки
1.5 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_mscom_Aggregation_h
#define mozilla_mscom_Aggregation_h
#include "mozilla/Attributes.h"
namespace mozilla {
namespace mscom {
/**
* This is used for stabilizing a COM object's reference count during
* construction when that object aggregates other objects. Since the aggregated
* object(s) may AddRef() or Release(), we need to artifically boost the
* refcount to prevent premature destruction. Note that we increment/decrement
* instead of AddRef()/Release() in this class because we want to adjust the
* refcount without causing any other side effects (like object destruction).
*/
template <typename RefCntT>
class MOZ_RAII StabilizedRefCount
{
public:
explicit StabilizedRefCount(RefCntT& aRefCnt)
: mRefCnt(aRefCnt)
{
++aRefCnt;
}
~StabilizedRefCount()
{
--mRefCnt;
}
StabilizedRefCount(const StabilizedRefCount&) = delete;
StabilizedRefCount(StabilizedRefCount&&) = delete;
StabilizedRefCount& operator=(const StabilizedRefCount&) = delete;
StabilizedRefCount& operator=(StabilizedRefCount&&) = delete;
private:
RefCntT& mRefCnt;
};
} // namespace mscom
} // namespace mozilla
#endif // mozilla_mscom_Aggregation_h