MIDIQ_AVAIL
if (MIDIQ_AVAIL(m->inq) > size) {
if (used && MIDIQ_AVAIL(m->outq) > m->hiwat) {
while (MIDIQ_AVAIL(m->outq) == 0) {
used = min(MIDIQ_AVAIL(m->outq), uio->uio_resid);
if (MIDIQ_AVAIL(m->outq) < m->hiwat)
#define MIDIQ_LEN(head) ((head).s - MIDIQ_AVAIL(head))