Issue 6489 - fix initialization moment of the default scheduler of DefaultPlatformBuilder

include/AdblockPlus/Platform.h

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 14 matching lines @@
 #include "AppInfo.h"
 #include "Scheduler.h"
 #include "FilterEngine.h"
 #include <mutex>
 #include <future>
 
 namespace AdblockPlus
 {
   struct IV8IsolateProvider;
   class JsEngine;
+  class OptionalAsyncExecutor;
 
   /**
    * AdblockPlus platform is the main component providing access to other
    * modules.
    *
    * It manages the functionality modules, e.g. JsEngine and FilterEngine as
    * well as allows to correctly work with asynchronous functionality.
    */
   class Platform
   {
@@ skipping 87 matching lines @@
   };
 
   /**
    * A helper class allowing to construct a default Platform and to obtain
    * the Scheduler used by Platform before the latter is constructed.
    */
   class DefaultPlatformBuilder : public Platform::CreationParameters
   {
   public:
     /**
+     * Private
+     */
+    typedef std::shared_ptr<OptionalAsyncExecutor> AsyncExecutorPtr;
+
+    DefaultPlatformBuilder();
+
+    /**
      * Constructs a default executor for asynchronous tasks. When Platform
      * is being destroyed it starts to ignore new tasks and waits for finishing
      * of already running tasks.
      * @return Scheduler allowing to execute tasks asynchronously.
      */
     Scheduler GetDefaultAsyncExecutor();
 
     /**
      * Constructs default implementation of `ITimer`.
      */
@@ skipping 14 matching lines @@
      * Constructs default implementation of `LogSystem`.
      */
     void CreateDefaultLogSystem();
 
     /**
      * Constructs Platform with default implementations of platform interfaces
      * when a corresponding field is nullptr and with a default Scheduler.
      */
     std::unique_ptr<Platform> CreatePlatform();
   private:
+    AsyncExecutorPtr sharedAsyncExecutor;
     Scheduler defaultScheduler;
   };
 }
 
 #endif // ADBLOCK_PLUS_PLATFORM_H