gecko-dev/netwerk/base/AutoClose.h
2020-02-11 16:20:08 +00:00

63 lines
1.5 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=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_net_AutoClose_h
#define mozilla_net_AutoClose_h
#include "nsCOMPtr.h"
#include "mozilla/Mutex.h"
namespace mozilla {
namespace net {
// A container for XPCOM streams (e.g. nsIAsyncInputStream) and other
// refcounted classes that need to have the Close() method called explicitly
// before they are destroyed.
template <typename T>
class AutoClose {
public:
AutoClose() : mMutex("net::AutoClose.mMutex") {}
~AutoClose() { CloseAndRelease(); }
explicit operator bool() {
MutexAutoLock lock(mMutex);
return mPtr;
}
already_AddRefed<T> forget() {
MutexAutoLock lock(mMutex);
return mPtr.forget();
}
void takeOver(nsCOMPtr<T>& rhs) { TakeOverInternal(rhs.forget()); }
void CloseAndRelease() { TakeOverInternal(nullptr); }
private:
void TakeOverInternal(already_AddRefed<T>&& aOther) {
nsCOMPtr<T> ptr(std::move(aOther));
{
MutexAutoLock lock(mMutex);
ptr.swap(mPtr);
}
if (ptr) {
ptr->Close();
}
}
void operator=(const AutoClose<T>&) = delete;
AutoClose(const AutoClose<T>&) = delete;
nsCOMPtr<T> mPtr;
Mutex mMutex;
};
} // namespace net
} // namespace mozilla
#endif // mozilla_net_AutoClose_h