c# - Why Doesn't the Code Deadlock -

Please explain to me why this code is not the reason of a deadlock?

  Fixed object listlock = new object (); Zero StartSync () {System.Threading.Task..Task.Factory.StartNew ((=) gt; Lock (base) support.opher ("mylistlist");}); } Public Observable Collection & lt; MyObjects & gt; MyList {Lock (Locklock) New Observation Collection & lt; MyObjects & gt; (_ MyOjectjectList); }}   
 Some background details: 
 The program is using the  MVVM  pattern and  MyList  is a  Datagrid < Strong> WPF UI  . 
  _Office  is a random list of objects. 
 
 This is because  OnPropertyChange  notifies the UI only that it will have to obtain new data from MyList and only without asking whether the UI actually receives data or No? 
 I know that OnPropertyChanged is said to be on a separate thread but the UI is present on a thread (the oo is not there) then the thread which is notified is also the thread that receives the data I think lock Will not be able to continue because of this?   
 
 
 The key is that the code of  changing property  handler some code schedule Does access  MyList  on the UI thread, but it does not wait for  to end it   
 Then, a possible sequence of events It is:  
 
  StartAsync ()  locks on a background thread.  >  is  for .  
  PropertyChanged  handler for codecs code  MyList  on the UI thread  
  By changing property  handler for returns.  
 The lock is in progress.  
 Use the UI thread attempt  MyList .  
 The UI threads lock without waiting, because no other thread is its owner.  
 One ?? |   
 Another way to put it: I hope you expect it to be handler for  PropertyChanged :  < Pre>  Dispatcher.Invoke (() => {If (e.PropertyName == "Mylist") {var newList = model.MyList; // Set new list as current value of some compulsion} });   
 But in fact, this is something like this (the only difference is the first line):  
  Dispatcher.BeginInvoke ((=) => {if ( E.PropertyName == "Mylist") {var newList = Model. MyList; // set as the current value of some bonds newList}});