xpcom/threads/nsICancelableRunnable.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 nsICancelableRunnable_h__
   8 #define nsICancelableRunnable_h__
   9
  10 #include "nsISupports.h"
  11
  12 #define NS_ICANCELABLERUNNABLE_IID                   \
  13   {                                                  \
  14     0xde93dc4c, 0x5eea, 0x4eb7, {                    \
  15       0xb6, 0xd1, 0xdb, 0xf1, 0xe0, 0xce, 0xf6, 0x5c \
  16     }                                                \
  17   }
  18
  19 class nsICancelableRunnable : public nsISupports {
  20  public:
  21   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ICANCELABLERUNNABLE_IID)
  22
  23   /*
  24    * Cancels a pending task, so that calling run() on the task is a no-op.
  25    * Calling cancel after the task execution has begun will be a no-op.
  26    * Calling this method twice is considered an error.
  27    *
  28    * @throws NS_ERROR_UNEXPECTED
  29    *   Indicates that the runnable has already been canceled.
  30    */
  31   virtual nsresult Cancel() = 0;
  32
  33  protected:
  34   nsICancelableRunnable() = default;
  35   virtual ~nsICancelableRunnable() = default;
  36 };
  37
  38 NS_DEFINE_STATIC_IID_ACCESSOR(nsICancelableRunnable, NS_ICANCELABLERUNNABLE_IID)
  39
  40 #endif  // nsICancelableRunnable_h__