int write (const MIDI::byte *msg, size_t msglen, MIDI::timestamp_t timestamp);
int read (MIDI::byte *buf, size_t bufsize);
/* waits for output to be cleared */
- void drain (int check_interval_usecs);
+ void drain (int check_interval_usecs, int total_usecs_to_wait);
/* clears async request communication channel */
void clear () {