#  define MUTEX_LOCK(m) \
    STMT_START {						\
	int _eC_;						\
	if ((_eC_ = pthread_mutex_lock((m))))			\
	    Perl_croak_nocontext("panic: MUTEX_LOCK (%d) [%s:%d]",	\
				 _eC_, __FILE__, __LINE__);	\
    } STMT_END