Removes all scheduled wakeup requests for a process from the
    timer queue, including those made by the caller or by other
    processes. The Schedule Wakeup ($SCHDWK) service makes scheduled
    wakeup requests.

    Format

      SYS$CANWAK  [pidadr] ,[prcnam]

    C Prototype

      int sys$canwak  (unsigned int *pidadr, void *prcnam);