/// <summary>
 /// Terminate a running job
 /// </summary>
 /// <param name="job">The job to terminate</param>
 public void TerminateJob(Job job)
 {
     Contract.Requires(job != null);
     Contract.Requires(job.State == JobState.Running);
     Contract.Ensures(job.State == JobState.Terminated);
     lock (_activityLock)
     {
         job.Terminate();
     }
 }