Issue 4938 - fix race conditions related to LazyFileSystem

test/Prefs.cpp

 /*
  * 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 13 matching lines @@
 
 namespace
 {
   typedef std::shared_ptr<AdblockPlus::FilterEngine> FilterEnginePtr;
 
   class TestFileSystem : public LazyFileSystem
   {
   public:
     IOBuffer prefsContents;
 
-    IOBuffer Read(const std::string& path) const
+    void Read(const std::string& path, const ReadCallback& callback) const override
     {
-      if (path == "prefs.json" && !prefsContents.empty())
-        return prefsContents;
+      scheduler([this, path, callback]
+      {
+        if (path == "prefs.json" && !prefsContents.empty())
+        {
+          callback(IOBuffer(prefsContents.cbegin(), prefsContents.cend()), "");
+          return;
+        }
 
-      return LazyFileSystem::Read(path);
+        LazyFileSystem::Read(path, callback);
+      });
     }
 
-    void Write(const std::string& path, const IOBuffer& content)
+    void Write(const std::string& path, const IOBuffer& content, const Callback& callback) override
     {
-      if (path == "prefs.json")
-        prefsContents = content;
-      else
-        LazyFileSystem::Write(path, content);
+      scheduler([this, path, content, callback]
+      {
+        if (path == "prefs.json")
+        {
+          prefsContents = content;
+          callback("");
+        }
+      });
     }
 
-    StatResult Stat(const std::string& path) const
+    void Stat(const std::string& path, const StatCallback& callback) const override
     {
-      if (path == "prefs.json")
+      scheduler([this, path, callback]
       {
-        StatResult result;
-        result.exists = result.isFile = !prefsContents.empty();
-        return result;
-      }
+        if (path == "prefs.json")
+        {
+          StatResult result;
+          result.exists = result.isFile = !prefsContents.empty();
+          callback(result, "");
+          return;
+        }
 
-      return LazyFileSystem::Stat(path);
+        LazyFileSystem::Stat(path, callback);
+      });
     }
   };
 
   class PrefsTest : public ::testing::Test
   {
   protected:
     std::shared_ptr<TestFileSystem> fileSystem;
     AdblockPlus::JsEnginePtr jsEngine;
 
     void SetUp()
@@ skipping 10 matching lines @@
       jsEngineParams.logSystem.reset(new LazyLogSystem());
       jsEngineParams.timer.reset(new NoopTimer());
       jsEngine = CreateJsEngine(std::move(jsEngineParams));
     }
 
     FilterEnginePtr CreateFilterEngine(const AdblockPlus::FilterEngine::Prefs& preconfiguredPrefs =
       AdblockPlus::FilterEngine::Prefs())
     {
       AdblockPlus::FilterEngine::CreationParameters createParams;
       createParams.preconfiguredPrefs = preconfiguredPrefs;
-      return AdblockPlus::FilterEngine::Create(jsEngine, createParams);
+      return ::CreateFilterEngine(*fileSystem, jsEngine, createParams);
     }
   };
 }
 
 TEST_F(PrefsTest, PrefsGetSet)
 {
   auto filterEngine = CreateFilterEngine();
   ASSERT_EQ("patterns.ini", filterEngine->GetPref("patternsfile").AsString());
   ASSERT_EQ(24, filterEngine->GetPref("patternsbackupinterval").AsInt());
   ASSERT_TRUE(filterEngine->GetPref("subscriptions_autoupdate").AsBool());
@@ skipping 16 matching lines @@
 {
   {
     auto filterEngine = CreateFilterEngine();
     ASSERT_EQ("patterns.ini", filterEngine->GetPref("patternsfile").AsString());
     ASSERT_EQ(24, filterEngine->GetPref("patternsbackupinterval").AsInt());
     ASSERT_TRUE(filterEngine->GetPref("subscriptions_autoupdate").AsBool());
 
     filterEngine->SetPref("patternsfile", jsEngine->NewValue("filters.ini"));
     filterEngine->SetPref("patternsbackupinterval", jsEngine->NewValue(48));
     filterEngine->SetPref("subscriptions_autoupdate", jsEngine->NewValue(false));
-
-    AdblockPlus::Sleep(100);
   }
   ASSERT_FALSE(fileSystem->prefsContents.empty());
 
   {
     ResetJsEngine();
     auto filterEngine = CreateFilterEngine();
     ASSERT_EQ("filters.ini", filterEngine->GetPref("patternsfile").AsString());
     ASSERT_EQ(48, filterEngine->GetPref("patternsbackupinterval").AsInt());
     ASSERT_FALSE(filterEngine->GetPref("subscriptions_autoupdate").AsBool());
   }
@@ skipping 55 matching lines @@
 TEST_F(PrefsTest, PrefsPersistWhenPreconfigured)
 {
   {
     AdblockPlus::FilterEngine::Prefs preconfiguredPrefs;
     preconfiguredPrefs.emplace("suppress_first_run_page", jsEngine->NewValue(true));
     auto filterEngine = CreateFilterEngine(preconfiguredPrefs);
 
     ASSERT_TRUE(filterEngine->GetPref("suppress_first_run_page").IsBool());
     ASSERT_TRUE(filterEngine->GetPref("suppress_first_run_page").AsBool());
     filterEngine->SetPref("suppress_first_run_page", jsEngine->NewValue(false));
-
-    AdblockPlus::Sleep(100);
   }
   ASSERT_FALSE(fileSystem->prefsContents.empty());
 
   {
     ResetJsEngine();
     AdblockPlus::FilterEngine::Prefs preconfiguredPrefs;
     preconfiguredPrefs.emplace("suppress_first_run_page", jsEngine->NewValue(true));
     auto filterEngine = CreateFilterEngine(preconfiguredPrefs);
 
     ASSERT_TRUE(filterEngine->GetPref("suppress_first_run_page").IsBool());
     ASSERT_FALSE(filterEngine->GetPref("suppress_first_run_page").AsBool());
   }
 }