Issue 5034 - Part 3: Create plain JsValue instead of JsValuePtr

src/JsValue.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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 23 matching lines @@
 AdblockPlus::JsValue::JsValue(AdblockPlus::JsValue&& src)
     : jsEngine(src.jsEngine),
       value(std::move(src.value))
 {
 }
 
 AdblockPlus::JsValue::JsValue(const JsValue& src)
   : jsEngine(src.jsEngine)
 {
   const JsContext context(src.jsEngine);
   value.reset(new v8::Persistent<v8::Value>(src.jsEngine->GetIsolate(), *src.value));

[hub, 2017/04/19 17:57:22]

Here I wonder if we shouldn't change JsValue::value declaration to be a
shared_ptr<> instead of a unique_ptr<> and thus avoid creating
v8::Persistent<v8::Value>.

[sergei, 2017/04/19 18:56:52]

I would not like to change it to std::shared_ptr, at least so far.

[hub, 2017/04/19 21:56:49]

ok.

 }
 
 AdblockPlus::JsValue::~JsValue()
 {
   if (value)
   {
     value->Dispose();
     value.reset();
   }
 }
 
 JsValue& AdblockPlus::JsValue::operator=(const JsValue& src)
 {
+  const JsContext context(src.jsEngine);
   if (value)
     value->Dispose();

[sergei, 2017/04/19 18:56:52]

actually, the lock (JsContext) should be acquired before calling of Dispose. I'm
afraid there is a bug in the destructor because it's not acquiring the lock.

[hub, 2017/04/19 21:56:49]

ah ok. Will fix this and the destructor.

   jsEngine = src.jsEngine;
-  const JsContext context(src.jsEngine);
   value.reset(new v8::Persistent<v8::Value>(src.jsEngine->GetIsolate(), *src.value));
 
   return *this;
 }
 
 bool AdblockPlus::JsValue::IsUndefined() const
 {
   const JsContext context(jsEngine);
   return UnwrapValue()->IsUndefined();
 }
@@ skipping 189 matching lines @@
   const v8::TryCatch tryCatch;
   v8::Local<v8::Function> func = v8::Local<v8::Function>::Cast(UnwrapValue());
   v8::Local<v8::Value> result = func->Call(thisObj, args.size(),
     args.size() ? &args[0] : nullptr);
 
   if (tryCatch.HasCaught())
     throw JsError(tryCatch.Exception(), tryCatch.Message());
 
   return JsValue(jsEngine, result);
 }