ref: cf9a3c2ad5a1e1a371cad0b6d5fc4164a68caf76
dir: /sys/src/libventi/queue.h/
typedef struct Queue Queue; #pragma incomplete Queue Queue *_vtqalloc(void); int _vtqsend(Queue*, void*); void *_vtqrecv(Queue*); void _vtqhangup(Queue*); void *_vtnbqrecv(Queue*); void _vtqdecref(Queue*); Queue *_vtqincref(Queue*);