Issue 4944 - Make creation of FilterEngine asynchronous.

src/FilterEngine.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 <algorithm>
 #include <cctype>
 #include <functional>
 #include <string>
 
 #include <AdblockPlus.h>
 #include "JsContext.h"
 #include "Thread.h"
+#include <mutex>
+#include <condition_variable>
 
 using namespace AdblockPlus;
 
 extern std::string jsSources[];
 
 Filter::Filter(JsValue&& value)
     : JsValue(std::move(value))
 {
   if (!IsObject())
     throw std::runtime_error("JavaScript value is not an object");
@@ skipping 91 matching lines @@
   params.push_back(shared_from_this());
   JsValuePtr result = func->Call(params);
   return result->AsBool();
 }
 
 bool Subscription::operator==(const Subscription& subscription) const
 {
   return GetProperty("url")->AsString() == subscription.GetProperty("url")->AsString();
 }
 
-FilterEngine::FilterEngine(JsEnginePtr jsEngine,
-                           const FilterEngine::Prefs& preconfiguredPrefs)
-    : jsEngine(jsEngine), initialized(false), firstRun(false), updateCheckId(0)
+namespace
 {
-  jsEngine->SetEventCallback("_init", std::bind(&FilterEngine::InitDone,
-      this, std::placeholders::_1));
+  class Sync
+  {
+  public:
+    Sync()
+      :initialized(false)
+    {
 
+    }
+    void Wait()
+    {
+      std::unique_lock<std::mutex> lock(mutex);
+      while (!initialized)
+        cv.wait(lock);
+    }
+    void Set()
+    {
+      {
+        std::unique_lock<std::mutex> lock(mutex);
+        initialized = true;
+      }
+      cv.notify_all();
+    }
+  private:
+    std::mutex mutex;
+    std::condition_variable cv;
+    bool initialized;
+  };
+}
+
+FilterEngine::FilterEngine(const JsEnginePtr& jsEngine)
+  : jsEngine(jsEngine), firstRun(false), updateCheckId(0)
+{
+}
+
+void FilterEngine::CreateAsync(const JsEnginePtr& jsEngine,
+  const FilterEngine::OnCreatedCallback& onCreated,
+  const FilterEngine::CreationParameters& params)
+{
+  FilterEnginePtr filterEngine(new FilterEngine(jsEngine));
+  auto sync = std::make_shared<Sync>();
+  jsEngine->SetEventCallback("_init", [jsEngine, filterEngine, onCreated, sync](JsValueList& params)
   {
-    // Lock the JS engine while we are loading scripts, no timeouts should fire
-    // until we are done.
-    const JsContext context(jsEngine);
+    filterEngine->firstRun = params.size() && params[0]->AsBool();
+    sync->Set();
+    onCreated(filterEngine);
+    jsEngine->RemoveEventCallback("_init");
+  });
 
-    // Set the preconfigured prefs
-    JsValuePtr preconfiguredPrefsObject = jsEngine->NewObject();
-    for (FilterEngine::Prefs::const_iterator it = preconfiguredPrefs.begin();
-         it != preconfiguredPrefs.end(); it++)
-    {
-      preconfiguredPrefsObject->SetProperty(it->first, it->second);
-    }
-    jsEngine->SetGlobalProperty("_preconfiguredPrefs", preconfiguredPrefsObject);
-    // Load adblockplus scripts
-    for (int i = 0; !jsSources[i].empty(); i += 2)
-      jsEngine->Evaluate(jsSources[i + 1], jsSources[i]);
+  // Lock the JS engine while we are loading scripts, no timeouts should fire
+  // until we are done.
+  const JsContext context(jsEngine);
+
+  // Set the preconfigured prefs
+  JsValuePtr preconfiguredPrefsObject = jsEngine->NewObject();
+  for (FilterEngine::Prefs::const_iterator it = params.preconfiguredPrefs.begin();
+    it != params.preconfiguredPrefs.end(); it++)
+  {
+    preconfiguredPrefsObject->SetProperty(it->first, it->second);
   }
+  jsEngine->SetGlobalProperty("_preconfiguredPrefs", preconfiguredPrefsObject);
+  // Load adblockplus scripts
+  for (int i = 0; !jsSources[i].empty(); i += 2)
+    jsEngine->Evaluate(jsSources[i + 1], jsSources[i]);
+}
 
-  // TODO: This should really be implemented via a conditional variable
-  while (!initialized)
-    ::Sleep(10);
+FilterEnginePtr FilterEngine::Create(const JsEnginePtr& jsEngine,
+  const FilterEngine::CreationParameters& params)
+{
+  FilterEnginePtr retValue;
+  Sync sync;
+  CreateAsync(jsEngine, [&retValue, &sync](const FilterEnginePtr& filterEngine)
+  {
+    retValue = filterEngine;
+    sync.Set();
+  }, params);
+  sync.Wait();
+  return retValue;
 }
 
 namespace
 {
   typedef std::map<FilterEngine::ContentType, std::string> ContentTypeMap;
 
   ContentTypeMap CreateContentTypeMap()
   {
     ContentTypeMap contentTypes;
     contentTypes[FilterEngine::CONTENT_TYPE_OTHER] = "OTHER";
@@ skipping 31 matching lines @@
   std::transform(contentType.begin(), contentType.end(), contentTypeUpper.begin(), ::toupper);
   for (ContentTypeMap::const_iterator it = contentTypes.begin();
        it != contentTypes.end(); it++)
   {
     if (it->second == contentTypeUpper)
       return it->first;
   }
   throw std::invalid_argument("Cannot convert argument to ContentType");
 }
 
-void FilterEngine::InitDone(JsValueList& params)
-{
-  jsEngine->RemoveEventCallback("_init");
-  initialized = true;
-  firstRun = params.size() && params[0]->AsBool();
-}
-
 bool FilterEngine::IsFirstRun() const
 {
   return firstRun;
 }
 
 FilterPtr FilterEngine::GetFilter(const std::string& text)
 {
   JsValuePtr func = jsEngine->Evaluate("API.getFilterFromText");
   JsValueList params;
   params.push_back(jsEngine->NewValue(text));
@@ skipping 273 matching lines @@
     FilterPtr filter = GetWhitelistingFilter(currentUrl, contentTypeMask, parentUrl);
     if (filter)
     {
       return filter;
     }
     currentUrl = parentUrl;
   }
   while (urlIterator != documentUrls.end());
   return FilterPtr();
 }