security/manager/ssl/CryptoTask.h

   1 /* -*- Mode: C++; tab-width: 8; 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 file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla__CryptoTask_h
   8 #define mozilla__CryptoTask_h
   9
  10 #include "mozilla/Attributes.h"
  11 #include "nsThreadUtils.h"
  12
  13 namespace mozilla {
  14
  15 /**
  16  * Frequently we need to run a task on a background thread without blocking
  17  * the main thread, and then call a callback on the main thread with the
  18  * result. This class provides the framework for that. Subclasses must:
  19  *
  20  *   (1) Override CalculateResult for the off-the-main-thread computation.
  21  *   (2) Override CallCallback() for the on-the-main-thread call of the
  22  *       callback.
  23  */
  24 class CryptoTask : public Runnable {
  25  public:
  26   nsresult Dispatch();
  27
  28  protected:
  29   CryptoTask() : Runnable("CryptoTask"), mRv(NS_ERROR_NOT_INITIALIZED) {}
  30
  31   virtual ~CryptoTask() = default;
  32
  33   /**
  34    * Called on a background thread (never the main thread). Its result will be
  35    * passed to CallCallback on the main thread.
  36    */
  37   virtual nsresult CalculateResult() = 0;
  38
  39   /**
  40    * Called on the main thread with the result from CalculateResult().
  41    */
  42   virtual void CallCallback(nsresult rv) = 0;
  43
  44  private:
  45   NS_IMETHOD Run() final;
  46
  47   nsresult mRv;
  48 };
  49
  50 }  // namespace mozilla
  51
  52 #endif  // mozilla__CryptoTask_h