Fix memory leaks in libadblockplus

src/FilterEngine.cpp

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2013 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 215 matching lines @@
   else
     return FilterPtr();
 }
 
 std::vector<std::string> FilterEngine::GetElementHidingSelectors(const std::string& domain) const
 {
   JsValuePtr func = jsEngine->Evaluate("API.getElementHidingSelectors");
   JsValueList params;
   params.push_back(jsEngine->NewValue(domain));
   JsValueList result = func->Call(params)->AsList();
+  jsEngine->Gc();

[Wladimir Palant, 2013/10/08 08:12:19]

This is a really bad idea, it will cause unnecessary delays. Embedders are only
supposed to call V8::IdleNotification() when they are actually idle.

As it is now, the Gc() method is only useful for testing. We can turn it into a
proper wrapper for V8::IdleNotification() - only calling V8::IdleNotification()
once and returning its return value, but with an additional lock to make sure no
JS code is running. However, we would actually need to call that in the
application using libadblockplus (in the message loop or its equivalent) because
otherwise we cannot know when that application is idle. Not quite easy but worth
looking into.

[Felix Dahlke, 2013/10/10 08:36:26]

I don't think we should look into this at this point. High memory usage is what
we get for using garbage collection to begin with, it's an issue we have on each
and every platform. The only real way to fix this is to put energy into avoiding
GC in the core code, which is what ChimeraScript would address.

I doubt that, once we have that, using v8::IdleNotification properly will gain
us much.

   std::vector<std::string> selectors;
   for (JsValueList::iterator it = result.begin(); it != result.end(); ++it)
     selectors.push_back((*it)->AsString());
   return selectors;
 }
 
 JsValuePtr FilterEngine::GetPref(const std::string& pref) const
 {
   JsValuePtr func = jsEngine->Evaluate("API.getPref");
   JsValueList params;
@@ skipping 24 matching lines @@
   func->Call(params);
 }
 
 void FilterEngine::UpdateCheckDone(const std::string& eventName, FilterEngine::UpdaterCallback callback, JsValueList& params)
 {
   jsEngine->RemoveEventCallback(eventName);
 
   std::string error(params.size() >= 1 && !params[0]->IsNull() ? params[0]->AsString() : "");
   callback(error);
 }