dom/media/SelfRef.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef SELF_REF_H
   8 #define SELF_REF_H
   9
  10 #include "mozilla/Attributes.h"
  11
  12 namespace mozilla {
  13
  14 template <class T>
  15 class SelfReference {
  16  public:
  17   SelfReference() : mHeld(false) {}
  18   ~SelfReference() {
  19     NS_ASSERTION(!mHeld, "Forgot to drop the self reference?");
  20   }
  21
  22   void Take(T* t) {
  23     if (!mHeld) {
  24       mHeld = true;
  25       t->AddRef();
  26     }
  27   }
  28   void Drop(T* t) {
  29     if (mHeld) {
  30       mHeld = false;
  31       t->Release();
  32     }
  33   }
  34
  35   MOZ_IMPLICIT operator bool() const { return mHeld; }
  36
  37   SelfReference(const SelfReference& aOther) = delete;
  38   void operator=(const SelfReference& aOther) = delete;
  39
  40  private:
  41   bool mHeld;
  42 };
  43
  44 }  // namespace mozilla
  45
  46 #endif  // SELF_REF_H