Discussion FileSystemWatcher runs too slow on Unity Editor

Hi, I'm trying to create my own file change monitoring system using

FileSystemWatcher

.
But the watcher performance is too bad for practical use.

Background

• I have additional codegen / datagen apps outside the Unity Editor.
• When they run, they write a lot of files inside Unity Assets folder.
  
• If Unity 'Auto Refresh' option is enabled, the two processes can interfere and unwanted result may occur.
  • So I need to disable the 'Auto Refresh' option, and refresh Asset import manually.(

    AssetDatabase.Refresh()

    )
• I want to notify users with GUI when file change is detected.
• I decided to make a watcher using

  FileSystemWatcher

  • A class with

    InitializeOnLoadAttribute 

    creates and holds the watcher instance.

Status

• The watcher class runs fine when built as a console app.
  • File change events are picked up immediately.
• The same class runs extremely slow when run in Unity Editor.
  • It took more than 5 seconds to get the change event.

Debug

• Create Watcher instance on a background thread(

  Task.Factory.StartNew()

  )
  • Still too slow.
  • According to the sourcecode, FileSystemWatcher uses Threadpool internally. So the watcher is running on a background thread already.

Question

• I want to know why the watcher run slow when in Unity Editor. What makes it differ from console?
• What is the proper way to implement my own file watcher in Unity?

 

got very similar issue. file system watcher on big directories (with recursion) - is quite slow and causes performance spikes