#define Lock SemLock
typedef
struct Lock {
	long	key;
	long	sem;
} Lock;
#define lock(xyz)		semlock(xyz)
#define unlock(xyz)	semunlock(xyz)
#define	canlock(xyz)	semcanlock(xyz)

extern	void	lock(Lock*);
extern	void	unlock(Lock*);
extern	int	canlock(Lock*);