Applying Luca's patch from bz 58744

        holding a mutex that uses this implementation, the server will deadlock

        and stop responding to requests.  When this occurs, the server will

        require a manual restart to recover.</p>

        <p>Solaris is a notable exception as it provides a mechanism which

        <p>Solaris and Linux are notable exceptions as they provide a mechanism which

        usually allows the mutex to be recovered after a child process

        terminates abnormally while holding a mutex.</p>

        <p>If your system implements the

        <p>If your system is POSIX compliant or if it implements the

        <code>pthread_mutexattr_setrobust_np()</code> function, you may be able

        to use the <code>pthread</code> option safely.</p>

        </note>