set to \texttt{PTHREAD\_MUTEX\_DEF\-AULT}. This type by itself does not define

the result of (a) locking a locked mutex, (b) unlocking a mutex locked by a

different thread, or (c) unlocking an unlocked mutex. Unix/Linux systems will

\texttt{PTHREAD\_\-MUT\-EX\_ERRORCHECK} (ignoring the recursive type, see

below). Thus, depending on a specific system, locking an already locked mutex

will result in a deadlock (\texttt{NORMAL}) or not (\texttt{ERRORCHECK}). In