Plan 9 from Bell Labs’s /usr/web/sources/contrib/quanstro/locktest/taslock.h
#define Lock TasLock typedef struct Lock { int val; } 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*);