xpcom/base/nsWeakReference.h
author Simon Sapin <simon.sapin@exyr.org>
Mon, 31 Dec 2018 01:01:49 +0100
changeset 452667 91e7ea77c846ae753fb3a28ab81598d2dc7ac865
parent 448947 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1518045 - Publish selectors 0.21.0 on crates.io. r=emilio This cherry-picks https://github.com/servo/servo/pull/22577, with the relevant lockfile update.

/* -*- 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 nsWeakReference_h__
#define nsWeakReference_h__

// nsWeakReference.h

// See mfbt/WeakPtr.h for a more typesafe C++ implementation of weak references

#include "nsIWeakReferenceUtils.h"

class nsWeakReference;

class nsSupportsWeakReference : public nsISupportsWeakReference {
 public:
  nsSupportsWeakReference() : mProxy(0) {}

  NS_DECL_NSISUPPORTSWEAKREFERENCE

 protected:
  inline ~nsSupportsWeakReference();

 private:
  friend class nsWeakReference;

  // Called (only) by an |nsWeakReference| from _its_ dtor.
  // The thread safety check is made by the caller.
  void NoticeProxyDestruction() { mProxy = nullptr; }

  nsWeakReference* MOZ_NON_OWNING_REF mProxy;

 protected:
  void ClearWeakReferences();
  bool HasWeakReferences() const { return !!mProxy; }
};

inline nsSupportsWeakReference::~nsSupportsWeakReference() {
  ClearWeakReferences();
}

#endif