\pagebreak \chapter{The \code{critical} Construct} \label{chap:critical} The following example includes several \code{critical} constructs . The example illustrates a queuing model in which a task is dequeued and worked on. To guard against multiple threads dequeuing the same task, the dequeuing operation must be in a \code{critical} region. Because the two queues in this example are independent, they are protected by \code{critical} constructs with different names, \plc{xaxis} and \plc{yaxis}. \cexample{critical}{1c} \fexample{critical}{1f}