xpcom/threads/nsIDiscardableRunnable.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=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 XPCOM_THREADS_NSIDISCARDABLERUNNABLE_H_
   8 #define XPCOM_THREADS_NSIDISCARDABLERUNNABLE_H_
   9
  10 #include "nsISupports.h"
  11
  12 /**
  13  * An interface implemented by nsIRunnable tasks for which nsIRunnable::Run()
  14  * might not be called.
  15  */
  16 #define NS_IDISCARDABLERUNNABLE_IID                  \
  17   {                                                  \
  18     0xde93dc4c, 0x755c, 0x4cdc, {                    \
  19       0x96, 0x76, 0x35, 0xc6, 0x48, 0x81, 0x59, 0x78 \
  20     }                                                \
  21   }
  22
  23 class NS_NO_VTABLE nsIDiscardableRunnable : public nsISupports {
  24  public:
  25   NS_DECLARE_STATIC_IID_ACCESSOR(NS_IDISCARDABLERUNNABLE_IID)
  26
  27   /**
  28    * Called exactly once on a queued task only if nsIRunnable::Run() is not
  29    * called.
  30    */
  31   virtual void OnDiscard() = 0;
  32
  33  protected:
  34   nsIDiscardableRunnable() = default;
  35   virtual ~nsIDiscardableRunnable() = default;
  36 };
  37
  38 NS_DEFINE_STATIC_IID_ACCESSOR(nsIDiscardableRunnable,
  39                               NS_IDISCARDABLERUNNABLE_IID)
  40
  41 #endif  // XPCOM_THREADS_NSIDISCARDABLERUNNABLE_H_