Issue #3593, #1197- fix isolate management

src/JsEngine.cpp

 /*
  * 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/>.
  */
 
 #include <AdblockPlus.h>
-
 #include "GlobalJsObject.h"
 #include "JsContext.h"
 #include "JsError.h"
 #include "Utils.h"
 
 namespace
 {
   v8::Handle<v8::Script> CompileScript(v8::Isolate* isolate,
     const std::string& source, const std::string& filename)
   {
@@ skipping 28 matching lines @@
   public:
     static void Init()
     {
       // it's threadsafe since C++11 and it will be instantiated only once and
       // destroyed at the application exit
       static V8Initializer initializer;
     }
   };
 }
 
-AdblockPlus::JsEngine::JsEngine()
-  : isolate(v8::Isolate::GetCurrent())
+AdblockPlus::ScopedV8Isolate::ScopedV8Isolate()
+  : isolate(v8::Isolate::New())
 {
 }
 
-AdblockPlus::JsEnginePtr AdblockPlus::JsEngine::New(const AppInfo& appInfo)
+AdblockPlus::ScopedV8Isolate::~ScopedV8Isolate()
+{
+  isolate->Dispose();
+  isolate = nullptr;
+}
+
+AdblockPlus::JsEngine::JsEngine(const ScopedV8IsolatePtr& isolate)
+  : isolate(isolate)
+{
+}
+
+AdblockPlus::JsEnginePtr AdblockPlus::JsEngine::New(const AppInfo& appInfo, const ScopedV8IsolatePtr& isolate)
 {
   V8Initializer::Init();

[Oleksandr, 2016/05/23 10:32:55]

Is there a reason for this move? I think it was better when Init() was called
here. We assume the caller uses ScopedV8Isolate, but what if that's not the
case?

[sergei, 2016/05/23 10:39:13]

Yes, there is a reason. Before we call `v8::Isolate::New()` (it's called in the
ctr of `ScopedV8Isolate`) we need to call `V8Initializer::Init();`. So the
caller should call `V8Initializer::Init()` before constructing isolate, but the
caller is likely not aware about it, especially because `isolate` is a default
value parameter which should not bother the caller with additional call of
`V8Initializer::Init()`.

-  JsEnginePtr result(new JsEngine());
+  JsEnginePtr result(new JsEngine(isolate));
 
-  const v8::Locker locker(result->isolate);
-  const v8::HandleScope handleScope;
+  const v8::Locker locker(result->GetIsolate());
+  const v8::Isolate::Scope isolateScope(result->GetIsolate());
+  const v8::HandleScope handleScope(result->GetIsolate());
 
-  result->context.reset(new v8::Persistent<v8::Context>(result->isolate,
-    v8::Context::New(result->isolate)));
+  result->context.reset(new v8::Persistent<v8::Context>(result->GetIsolate(),
+    v8::Context::New(result->GetIsolate())));
   v8::Local<v8::Object> globalContext = v8::Local<v8::Context>::New(
-    result->isolate, *result->context)->Global();
+    result->GetIsolate(), *result->context)->Global();
   result->globalJsObject = JsValuePtr(new JsValue(result, globalContext));
   AdblockPlus::GlobalJsObject::Setup(result, appInfo, result->globalJsObject);
   return result;
 }
 
 AdblockPlus::JsValuePtr AdblockPlus::JsEngine::Evaluate(const std::string& source,
     const std::string& filename)
 {
   const JsContext context(shared_from_this());
   const v8::TryCatch tryCatch;
-  const v8::Handle<v8::Script> script = CompileScript(isolate, source,
+  const v8::Handle<v8::Script> script = CompileScript(GetIsolate(), source,
     filename);
   CheckTryCatch(tryCatch);
   v8::Local<v8::Value> result = script->Run();
   CheckTryCatch(tryCatch);
   return JsValuePtr(new JsValue(shared_from_this(), result));
 }
 
 void AdblockPlus::JsEngine::SetEventCallback(const std::string& eventName,
     AdblockPlus::JsEngine::EventCallback callback)
 {
@@ skipping 14 matching lines @@
 
 void AdblockPlus::JsEngine::Gc()
 {
   while (!v8::V8::IdleNotification());
 }
 
 AdblockPlus::JsValuePtr AdblockPlus::JsEngine::NewValue(const std::string& val)
 {
   const JsContext context(shared_from_this());
   return JsValuePtr(new JsValue(shared_from_this(),
-    Utils::ToV8String(isolate, val)));
+    Utils::ToV8String(GetIsolate(), val)));
 }
 
 AdblockPlus::JsValuePtr AdblockPlus::JsEngine::NewValue(int64_t val)
 {
   const JsContext context(shared_from_this());
   return JsValuePtr(new JsValue(shared_from_this(),
-    v8::Number::New(isolate, val)));
+    v8::Number::New(GetIsolate(), val)));
 }
 
 AdblockPlus::JsValuePtr AdblockPlus::JsEngine::NewValue(bool val)
 {
   const JsContext context(shared_from_this());
   return JsValuePtr(new JsValue(shared_from_this(), v8::Boolean::New(val)));
 }
 
 AdblockPlus::JsValuePtr AdblockPlus::JsEngine::NewObject()
 {
@@ skipping 83 matching lines @@
 
 
 void AdblockPlus::JsEngine::SetGlobalProperty(const std::string& name, 
                                               AdblockPlus::JsValuePtr value)
 {
   if (!globalJsObject)
     throw std::runtime_error("Global object cannot be null");
 
   globalJsObject->SetProperty(name, value);
 }