ref: d09e5a7af724cbb2df7a066a805cf6c8303a4b39
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*);