Play slick and Async - is it a race condition?

Question

Reading Play-Slick DBAction code, I thought that this code might contain a race condition:

object DBAction{
  // snip

  def apply(r: (RequestWithDbSession)          


        

Answer 1

I am not sure if that is called a race condition. However to me it seems that you are correct that something is wrong here. The session might no longer be valid when the future executes the code.

It would be better to invert the execution and request a database session from within the future:

Async {
  Future {
    DB.withSession{ s:scala.slick.session.Session =>
      r( RequestWithDbSession(request, s) )
    }
  }
}