Don`t use references to JsEngine to avoid use-after-free errors,switch to shared_ptr instead

src/FileSystemJsObject.cpp

 #include <AdblockPlus/FileSystem.h>
 #include <stdexcept>
 #include <sstream>
 #include <vector>
 
-#include <AdblockPlus/JsEngine.h>
 #include <AdblockPlus/JsValue.h>
 #include "FileSystemJsObject.h"
 #include "Utils.h"
 #include "Thread.h"
 #include "Utils.h"
 
 using namespace AdblockPlus;
 
 namespace
 {
   class IoThread : public Thread
   {
   public:
-    IoThread(JsEngine& jsEngine, JsValuePtr callback)
-      : jsEngine(jsEngine), fileSystem(jsEngine.GetFileSystem()),
+    IoThread(JsEnginePtr jsEngine, JsValuePtr callback)
+      : jsEngine(jsEngine), fileSystem(jsEngine->GetFileSystem()),
         callback(callback)
     {
     }
 
   protected:
-    JsEngine& jsEngine;
+    JsEnginePtr jsEngine;
     FileSystemPtr fileSystem;
     JsValuePtr callback;
   };
 
   class ReadThread : public IoThread
   {
   public:
-    ReadThread(JsEngine& jsEngine, JsValuePtr callback,
+    ReadThread(JsEnginePtr jsEngine, JsValuePtr callback,
                const std::string& path)
       : IoThread(jsEngine, callback), path(path)
     {
     }
 
     void Run()
     {
       std::string content;
       std::string error;
       try
       {
         std::tr1::shared_ptr<std::istream> stream = fileSystem->Read(path);
         content = Utils::Slurp(*stream);
       }
       catch (std::exception& e)
       {
         error = e.what();
       }
       catch (...)
       {
         error =  "Unknown error while reading from " + path;
       }
 
       const JsEngine::Context context(jsEngine);
-      JsValuePtr result = jsEngine.NewObject();
+      JsValuePtr result = jsEngine->NewObject();
       result->SetProperty("content", content);
       result->SetProperty("error", error);
       JsValueList params;
       params.push_back(result);
       callback->Call(params);
       delete this;
     }
 
   private:
     std::string path;
   };
 
   class WriteThread : public IoThread
   {
   public:
-    WriteThread(JsEngine& jsEngine, JsValuePtr callback,
+    WriteThread(JsEnginePtr jsEngine, JsValuePtr callback,
                 const std::string& path, const std::string& content)
       : IoThread(jsEngine, callback), path(path), content(content)
     {
     }
 
     void Run()
     {
       std::string error;
       try
       {
         std::tr1::shared_ptr<std::ostream> stream(new std::stringstream);
         *stream << content;
         fileSystem->Write(path, stream);
       }
       catch (std::exception& e)
       {
         error = e.what();
       }
       catch (...)
       {
         error = "Unknown error while writing to " + path;
       }
 
       const JsEngine::Context context(jsEngine);
-      JsValuePtr errorValue = jsEngine.NewValue(error);
+      JsValuePtr errorValue = jsEngine->NewValue(error);
       JsValueList params;
       params.push_back(errorValue);
       callback->Call(params);
       delete this;
     }
 
   private:
     std::string path;
     std::string content;
   };
 
   class MoveThread : public IoThread
   {
   public:
-    MoveThread(JsEngine& jsEngine, JsValuePtr callback,
+    MoveThread(JsEnginePtr jsEngine, JsValuePtr callback,
                const std::string& fromPath, const std::string& toPath)
       : IoThread(jsEngine, callback), fromPath(fromPath), toPath(toPath)
     {
     }
 
     void Run()
     {
       std::string error;
       try
       {
         fileSystem->Move(fromPath, toPath);
       }
       catch (std::exception& e)
       {
         error = e.what();
       }
       catch (...)
       {
         error = "Unknown error while moving " + fromPath + " to " + toPath;
       }
 
       const JsEngine::Context context(jsEngine);
-      JsValuePtr errorValue = jsEngine.NewValue(error);
+      JsValuePtr errorValue = jsEngine->NewValue(error);
       JsValueList params;
       params.push_back(errorValue);
       callback->Call(params);
       delete this;
     }
 
   private:
     std::string fromPath;
     std::string toPath;
   };
 
   class RemoveThread : public IoThread
   {
   public:
-    RemoveThread(JsEngine& jsEngine, JsValuePtr callback,
+    RemoveThread(JsEnginePtr jsEngine, JsValuePtr callback,
                  const std::string& path)
       : IoThread(jsEngine, callback), path(path)
     {
     }
 
     void Run()
     {
       std::string error;
       try
       {
         fileSystem->Remove(path);
       }
       catch (std::exception& e)
       {
         error = e.what();
       }
       catch (...)
       {
         error = "Unknown error while removing " + path;
       }
 
       const JsEngine::Context context(jsEngine);
-      JsValuePtr errorValue = jsEngine.NewValue(error);
+      JsValuePtr errorValue = jsEngine->NewValue(error);
       JsValueList params;
       params.push_back(errorValue);
       callback->Call(params);
       delete this;
     }
 
   private:
     std::string path;
   };
 
   class StatThread : public IoThread
   {
   public:
-    StatThread(JsEngine& jsEngine, JsValuePtr callback,
+    StatThread(JsEnginePtr jsEngine, JsValuePtr callback,
                const std::string& path)
       : IoThread(jsEngine, callback), path(path)
     {
     }
 
     void Run()
     {
       std::string error;
       FileSystem::StatResult statResult;
       try
       {
         statResult = fileSystem->Stat(path);
       }
       catch (std::exception& e)
       {
         error = e.what();
       }
       catch (...)
       {
         error = "Unknown error while calling stat on " + path;
       }
 
       const JsEngine::Context context(jsEngine);
-      JsValuePtr result = jsEngine.NewObject();
+      JsValuePtr result = jsEngine->NewObject();
       result->SetProperty("exists", statResult.exists);
       result->SetProperty("isFile", statResult.isFile);
       result->SetProperty("isDirectory", statResult.isDirectory);
       result->SetProperty("lastModified", statResult.lastModified);
       result->SetProperty("error", error);
 
       JsValueList params;
       params.push_back(result);
       callback->Call(params);
       delete this;
     }
 
   private:
     std::string path;
   };
 
   v8::Handle<v8::Value> ReadCallback(const v8::Arguments& arguments)
   {
-    AdblockPlus::JsEngine& jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
-    AdblockPlus::JsValueList converted = jsEngine.ConvertArguments(arguments);
+    AdblockPlus::JsEnginePtr jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
+    AdblockPlus::JsValueList converted = jsEngine->ConvertArguments(arguments);
 
     if (converted.size() != 2)
       return v8::ThrowException(v8::String::New(
         "_fileSystem.read requires 2 parameters"));
     if (!converted[1]->IsFunction())
       return v8::ThrowException(v8::String::New(
         "Second argument to _fileSystem.read must be a function"));
     ReadThread* const readThread = new ReadThread(jsEngine, converted[1],
         converted[0]->AsString());
     readThread->Start();
     return v8::Undefined();
   }
 
   v8::Handle<v8::Value> WriteCallback(const v8::Arguments& arguments)
   {
-    AdblockPlus::JsEngine& jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
-    AdblockPlus::JsValueList converted = jsEngine.ConvertArguments(arguments);
+    AdblockPlus::JsEnginePtr jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
+    AdblockPlus::JsValueList converted = jsEngine->ConvertArguments(arguments);
 
     if (converted.size() != 3)
       return v8::ThrowException(v8::String::New(
         "_fileSystem.write requires 3 parameters"));
     if (!converted[2]->IsFunction())
       return v8::ThrowException(v8::String::New(
         "Third argument to _fileSystem.write must be a function"));
     WriteThread* const writeThread = new WriteThread(jsEngine, converted[2],
         converted[0]->AsString(), converted[1]->AsString());
     writeThread->Start();
     return v8::Undefined();
   }
 
   v8::Handle<v8::Value> MoveCallback(const v8::Arguments& arguments)
   {
-    AdblockPlus::JsEngine& jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
-    AdblockPlus::JsValueList converted = jsEngine.ConvertArguments(arguments);
+    AdblockPlus::JsEnginePtr jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
+    AdblockPlus::JsValueList converted = jsEngine->ConvertArguments(arguments);
 
     if (converted.size() != 3)
       return v8::ThrowException(v8::String::New(
         "_fileSystem.move requires 3 parameters"));
     if (!converted[2]->IsFunction())
       return v8::ThrowException(v8::String::New(
         "Third argument to _fileSystem.move must be a function"));
     MoveThread* const moveThread = new MoveThread(jsEngine, converted[2],
         converted[0]->AsString(), converted[1]->AsString());
     moveThread->Start();
     return v8::Undefined();
   }
 
   v8::Handle<v8::Value> RemoveCallback(const v8::Arguments& arguments)
   {
-    AdblockPlus::JsEngine& jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
-    AdblockPlus::JsValueList converted = jsEngine.ConvertArguments(arguments);
+    AdblockPlus::JsEnginePtr jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
+    AdblockPlus::JsValueList converted = jsEngine->ConvertArguments(arguments);
 
     if (converted.size() != 2)
       return v8::ThrowException(v8::String::New(
         "_fileSystem.remove requires 2 parameters"));
     if (!converted[1]->IsFunction())
       return v8::ThrowException(v8::String::New(
         "Second argument to _fileSystem.remove must be a function"));
     RemoveThread* const removeThread = new RemoveThread(jsEngine, converted[1],
         converted[0]->AsString());
     removeThread->Start();
     return v8::Undefined();
   }
 
   v8::Handle<v8::Value> StatCallback(const v8::Arguments& arguments)
   {
-    AdblockPlus::JsEngine& jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
-    AdblockPlus::JsValueList converted = jsEngine.ConvertArguments(arguments);
+    AdblockPlus::JsEnginePtr jsEngine = AdblockPlus::JsEngine::FromArguments(arguments);
+    AdblockPlus::JsValueList converted = jsEngine->ConvertArguments(arguments);
 
     if (converted.size() != 2)
       return v8::ThrowException(v8::String::New(
         "_fileSystem.stat requires 2 parameters"));
     if (!converted[1]->IsFunction())
       return v8::ThrowException(v8::String::New(
         "Second argument to _fileSystem.stat must be a function"));
     StatThread* const statThread = new StatThread(jsEngine, converted[1],
         converted[0]->AsString());
     statThread->Start();
     return v8::Undefined();
   }
 }
 
-JsValuePtr FileSystemJsObject::Setup(JsEngine& jsEngine, JsValuePtr obj)
+JsValuePtr FileSystemJsObject::Setup(JsEnginePtr jsEngine, JsValuePtr obj)
 {
-  obj->SetProperty("read", jsEngine.NewCallback(::ReadCallback));
-  obj->SetProperty("write", jsEngine.NewCallback(::WriteCallback));
-  obj->SetProperty("move", jsEngine.NewCallback(::MoveCallback));
-  obj->SetProperty("remove", jsEngine.NewCallback(::RemoveCallback));
-  obj->SetProperty("stat", jsEngine.NewCallback(::StatCallback));
+  obj->SetProperty("read", jsEngine->NewCallback(::ReadCallback));
+  obj->SetProperty("write", jsEngine->NewCallback(::WriteCallback));
+  obj->SetProperty("move", jsEngine->NewCallback(::MoveCallback));
+  obj->SetProperty("remove", jsEngine->NewCallback(::RemoveCallback));
+  obj->SetProperty("stat", jsEngine->NewCallback(::StatCallback));
   return obj;
 }