Issue 4938 - fix race conditions related to LazyFileSystem

test/BaseJsTest.h

 /*
  * 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 131 matching lines @@
 
 class ThrowingWebRequest : public AdblockPlus::IWebRequest
 {
 public:
   void GET(const std::string& url, const AdblockPlus::HeaderList& requestHeaders, const GetCallback&) override
   {
     throw std::runtime_error("Unexpected GET: " + url);
   }
 };
 
-class LazyFileSystem : public AdblockPlus::IFileSystem, public AdblockPlus::FileSystem
+class LazyFileSystem : public AdblockPlus::IFileSystem
 {
 public:
-  IOBuffer Read(const std::string& path) const
+  typedef std::function<void()> Task;
+  typedef std::function<void(const Task& task)> Scheduler;
+  static void ExecuteImmediately(const Task& task)
   {
-    std::string dummyData("");
-    if (path == "patterns.ini")
-      dummyData = "# Adblock Plus preferences\n[Subscription]\nurl=~fl~";
-    else if (path == "prefs.json")
-      dummyData = "{}";
-    return IOBuffer(dummyData.cbegin(), dummyData.cend());
+    if (task)
+      task();
   }
-
-  void Read(const std::string& path, const ReadCallback& callback) const
-  {
-    std::thread([this, path, callback]
-    {
-      auto data = Read(path);
-      callback(std::move(data), "");
-    }).detach();
-  }
-
-  void Write(const std::string& path, const IOBuffer& content)
+  explicit LazyFileSystem(const Scheduler& scheduler = LazyFileSystem::ExecuteImmediately)
+    : scheduler(scheduler)
   {
   }
 
-  void Write(const std::string& path, const IOBuffer& data,
-             const Callback& callback)
+  void Read(const std::string& path, const ReadCallback& callback) const override
   {
-    std::thread([this, path, data, callback]
+    scheduler([path, callback]
     {
-      Write(path, data);
-      callback("");
-    }).detach();
+      if (path == "patterns.ini")
+      {
+        std::string dummyData = "# Adblock Plus preferences\n[Subscription]\nurl=~fl~";
+        callback(IOBuffer(dummyData.cbegin(), dummyData.cend()), "");
+      }
+      else if (path == "prefs.json")
+      {
+        std::string dummyData = "{}";
+        callback(IOBuffer(dummyData.cbegin(), dummyData.cend()), "");
+      }
+    });
   }
 
-  void Move(const std::string& fromPath, const std::string& toPath)
+  void Write(const std::string& path, const IOBuffer& data,
+             const Callback& callback) override
   {
   }
 
+
   void Move(const std::string& fromPath, const std::string& toPath,
-            const Callback& callback)
-  {
-    std::thread([this, fromPath, toPath, callback]
-    {
-      Move(fromPath, toPath);
-      callback("");
-    }).detach();
-  }
-
-  void Remove(const std::string& path)
+            const Callback& callback) override
   {
   }
 
-  void Remove(const std::string& path, const Callback& callback)
+  void Remove(const std::string& path, const Callback& callback) override
   {
-    std::thread([this, path, callback]
-    {
-      Remove(path);
-      callback("");
-    }).detach();
   }
 
-  StatResult Stat(const std::string& path) const
+  void Stat(const std::string& path, const StatCallback& callback) const override
   {
-    StatResult result;
-    if (path == "patterns.ini")
+    scheduler([path, callback]
     {
-      result.exists = true;
-      result.isFile = true;
-    }
-    return result;
+      StatResult result;
+      if (path == "patterns.ini")
+      {
+        result.exists = true;
+        result.isFile = true;
+      }
+      callback(result, "");
+    });
   }
 
-  void Stat(const std::string& path, const StatCallback& callback) const
-  {
-    std::thread([this, path, callback]
-    {
-      callback(Stat(path), "");
-    }).detach();
-  }
-
-  std::string Resolve(const std::string& path) const
+  std::string Resolve(const std::string& path) const override
   {
     return path;
   }
+public:
+  Scheduler scheduler;
 };
 
+AdblockPlus::FilterEnginePtr CreateFilterEngine(LazyFileSystem& fileSystem,
+  const AdblockPlus::JsEnginePtr& jsEngine,
+  const AdblockPlus::FilterEngine::CreationParameters& creationParams = AdblockPlus::FilterEngine::CreationParameters());
+
 class NoopWebRequest : public AdblockPlus::IWebRequest
 {
 public:
   void GET(const std::string& url, const AdblockPlus::HeaderList& requestHeaders, const GetCallback& callback) override
   {
   }
 };
 
 struct DelayedWebRequestTask
 {
@@ skipping 39 matching lines @@
 protected:
   AdblockPlus::JsEnginePtr jsEngine;
 
   virtual void SetUp()
   {
     jsEngine = CreateJsEngine();
   }
 };
 
 #endif