Issue 4938 - fix race conditions and get rid of hacks related to DefaultFileSystem

src/DefaultFileSystem.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 187 matching lines @@
 void DefaultFileSystemSync::SetBasePath(const std::string& path)
 {
   basePath = path;
 
   if (*basePath.rbegin() == PATH_SEPARATOR)
   {
     basePath.resize(basePath.size() - 1);
   }
 }
 
-DefaultFileSystem::DefaultFileSystem(std::unique_ptr<DefaultFileSystemSync> syncImpl)
-  : syncImpl(std::move(syncImpl))
+DefaultFileSystem::DefaultFileSystem(const Scheduler& scheduler, std::unique_ptr<DefaultFileSystemSync> syncImpl)
+  : scheduler(scheduler), syncImpl(std::move(syncImpl))
 {
 }
 
 void DefaultFileSystem::Read(const std::string& path,
                              const ReadCallback& callback) const
 {
-  std::thread([this, path, callback]
+  scheduler([this, path, callback]
   {
     std::string error;
     try
     {
       auto data = syncImpl->Read(path);
       callback(std::move(data), error);
       return;
     }
     catch (std::exception& e)
     {
       error = e.what();
     }
     catch (...)
     {
       error =  "Unknown error while reading from " + path;
     }
     callback(IOBuffer(), error);
-  }).detach();
+  });
 }
 
 void DefaultFileSystem::Write(const std::string& path,
                               const IOBuffer& data,
                               const Callback& callback)
 {
-  std::thread([this, path, data, callback]
+  scheduler([this, path, data, callback]
   {
     std::string error;
     try
     {
       syncImpl->Write(path, data);
     }
     catch (std::exception& e)
     {
       error = e.what();
     }
     catch (...)
     {
       error = "Unknown error while writing to " + path;
     }
     callback(error);
-  }).detach();
+  });
 }
 
 void DefaultFileSystem::Move(const std::string& fromPath,
                              const std::string& toPath,
                              const Callback& callback)
 {
-  std::thread([this, fromPath, toPath, callback]
+  scheduler([this, fromPath, toPath, callback]
   {
     std::string error;
     try
     {
       syncImpl->Move(fromPath, toPath);
     }
     catch (std::exception& e)
     {
       error = e.what();
     }
     catch (...)
     {
       error = "Unknown error while moving " + fromPath + " to " + toPath;
     }
     callback(error);
-  }).detach();
+  });
 }
 
 void DefaultFileSystem::Remove(const std::string& path,
                                const Callback& callback)
 {
-  std::thread([this, path, callback]
+  scheduler([this, path, callback]
   {
     std::string error;
     try
     {
       syncImpl->Remove(path);
     }
     catch (std::exception& e)
     {
       error = e.what();
     }
     catch (...)
     {
       error = "Unknown error while removing " + path;
     }
     callback(error);
-  }).detach();
+  });
 }
 
 void DefaultFileSystem::Stat(const std::string& path,
                              const StatCallback& callback) const
 {
-  std::thread([this, path, callback]
+  scheduler([this, path, callback]
   {
     std::string error;
     try
     {
       auto result = syncImpl->Stat(path);
       callback(result, error);
       return;
     }
     catch (std::exception& e)
     {
       error = e.what();
     }
     catch (...)
     {
       error = "Unknown error while calling stat on " + path;
     }
     callback(StatResult(), error);
-  }).detach();
+  });
 }
 
 std::string DefaultFileSystem::Resolve(const std::string& path) const
 {
   return syncImpl->Resolve(path);
 }