title: CallContext vs ThreadStatic
body: <p>What are differences between CallContext and ThreadStatic?</p>
  
  <p>I've understood that in an ASP.NET environment data stored in CallContext could be persisted throughout the request until it ends while ThreadStatic may or may not work since the request may switch threads. I've also learned that the HttpContext is internally stored using the CallContext.</p>
  
  <p>In a regular application they both seem to persist throughout the same thread call. When isn't this the case? </p>
  
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  <p><strong>Edit:</strong> In the comments I learned that the call context is an abstraction over a thread static store. The ASP.NET framework explicitly moves the data from one thread to the next that is to handle one request. Other framework that wants to provide thread agility could do the same to for contextual storage.</p>