title: How to use a swift class reference in a objC class, and an objC reference in that previous swift file simultaneously?
body: <p>Suppose I have 2 class in a xCode project.
  parent.m, and child.swift.</p>
  
  <p>In parent.m
  I require child *ref;</p>
  
  <p>in child.swift
  I require weak var ref:parent!</p>
  
  <p>I know how to independently use objc class in swift (using bridging header) or vice versa, but they seem to unable to call each other from their classes.
  Is there even a way to do it? </p>
  
  <p>edit: the problem is solved. 
  Cause:
  The problem was a deadlock situation.
  in order to use parent.m in child.swift,
  I prepared a bridging header and imported parent.m</p>
  
  <p>and in order to use child.swift in parent, I included the system generated  in parent.m .
  However the some other prior imports in parent.m were creating the deadlock situation.</p>
  
  <p>Upon moving up the import order of  the problem was solved.</p>