Question

Are static exception instances safe to use? Any good reason to avoid the following?

public class ResourceHttpHandler : IHttpHandler {     private static HttpException notFoundException =                 new HttpException(                     (int)HttpStatusCode.NotFound,                     'Assembly Not Found');      public bool IsReusable     {         get { return true; }     }      public void ProcessRequest(HttpContext context)     {         ....         throw notFoundException;         ....     } } 

Answer 1

An exception’s stacktrace is set when it is thrown (http://msdn.microsoft.com/en-us/library/system.exception.stacktrace.aspx), so this code is not thread safe.

Multiple threads will be using the same exception object and anyone relying on the content of the exception will get confusing results.