Issue 4692 - Dont' keep a strong reference from timer thread

include/AdblockPlus/JsEngine.h

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #ifndef ADBLOCK_PLUS_JS_ENGINE_H
 #define ADBLOCK_PLUS_JS_ENGINE_H
 
 #include <functional>
 #include <map>
+#include <list>
 #include <stdexcept>
 #include <stdint.h>
 #include <string>
 #include <mutex>
 #include <AdblockPlus/AppInfo.h>
 #include <AdblockPlus/LogSystem.h>
 #include <AdblockPlus/FileSystem.h>
 #include <AdblockPlus/JsValue.h>
 #include <AdblockPlus/WebRequest.h>
 
@@ skipping 41 matching lines @@
    */
   typedef std::shared_ptr<ScopedV8Isolate> ScopedV8IsolatePtr;
 
   /**
    * JavaScript engine used by `FilterEngine`, wraps v8.
    */
   class JsEngine : public std::enable_shared_from_this<JsEngine>
   {
     friend class JsValue;
     friend class JsContext;
-

[Oleksandr, 2017/03/24 12:15:25]

Nit: I'm sure you can guess :). Unrelated?

[sergei, 2017/03/24 12:34:39]

Done.

   public:
     /**
      * Event callback function.
      */
     typedef std::function<void(JsValueList& params)> EventCallback;
 
     /**
     * Callback function returning false when current connection is not allowed
     * e.g. because it is a metered connection.
     */
@@ skipping 168 matching lines @@
     void SetGlobalProperty(const std::string& name, AdblockPlus::JsValuePtr value);
 
     /**
      * Returns a pointer to associated v8::Isolate.
      */
     v8::Isolate* GetIsolate()
     {
       return isolate->Get();
     }
 
+    // Private functionality required to implement timers.
+    struct TimerTaskInfo
+    {
+      ~TimerTaskInfo();
+      int delay;
+      std::vector<std::unique_ptr<v8::Persistent<v8::Value>>> arguments;

[sergei, 2017/03/23 17:27:13]

We need std::unique_ptr here because v8::Persistent from currently used version
of v8 does not support move semantics.

+    };
+    typedef std::list<TimerTaskInfo> TimerTaskInfos;
+    struct TimerTask
+    {
+      std::weak_ptr<JsEngine> weakJsEngine;
+      TimerTaskInfos::const_iterator ii_taskInfo;

[Oleksandr, 2017/03/24 12:15:25]

Nit: It is not immediately clear to me what ii_ stands for. How about
taskInfoIterator?

[sergei, 2017/03/24 12:34:39]

Done.

+    };
+    TimerTask CreateTimerTask(const v8::Arguments& arguments);
+    void CallTimerTask(TimerTaskInfos::const_iterator ii_taskInfo);
   private:
     explicit JsEngine(const ScopedV8IsolatePtr& isolate);
 
     JsValuePtr GetGlobalObject();
 
     /// Isolate must be disposed only after disposing of all objects which are
     /// using it.
     ScopedV8IsolatePtr isolate;
 
     FileSystemPtr fileSystem;
     WebRequestPtr webRequest;
     LogSystemPtr logSystem;
     std::unique_ptr<v8::Persistent<v8::Context>> context;
     EventMap eventCallbacks;
     std::mutex eventCallbacksMutex;
     std::mutex isConnectionAllowedMutex;
     IsConnectionAllowedCallback isConnectionAllowed;
+    TimerTaskInfos timerTaskInfos;
   };
 }
 
 #endif