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       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 mozilla_JSObjectHolder_h
       8             : #define mozilla_JSObjectHolder_h
       9             : 
      10             : #include "js/RootingAPI.h"
      11             : #include "nsISupportsImpl.h"
      12             : 
      13             : namespace mozilla {
      14             : 
      15             : // This class is useful when something on one thread needs to keep alive
      16             : // a JS Object from another thread. If they are both on the same thread, the
      17             : // owning class should instead be made a cycle collected SCRIPT_HOLDER class.
      18             : // This object should only be AddRefed and Released on the same thread as
      19             : // mJSObject.
      20             : //
      21             : // Note that this keeps alive the JS object until it goes away, so be sure not to
      22             : // create cycles that keep alive the holder.
      23             : //
      24             : // JSObjectHolder is ISupports to make it usable with NS_ReleaseOnMainThread.
      25             : class JSObjectHolder final : public nsISupports
      26             : {
      27             : public:
      28           0 :   JSObjectHolder(JSContext* aCx, JSObject* aObject) : mJSObject(aCx, aObject) {}
      29             : 
      30             :   NS_DECL_ISUPPORTS
      31             : 
      32           0 :   JSObject* GetJSObject() { return mJSObject; }
      33             : 
      34             : private:
      35           0 :   ~JSObjectHolder() {}
      36             : 
      37             :   JS::PersistentRooted<JSObject*> mJSObject;
      38             : };
      39             : 
      40             : } // namespace mozilla
      41             : 
      42             : #endif // mozilla_JSObjectHolder_h