CALLOUT_PENDING
if (c->c_iflags & CALLOUT_PENDING) {
c->c_iflags &= ~ CALLOUT_PENDING;
c->c_iflags |= (CALLOUT_DFRMIGRATION | CALLOUT_PENDING);
if ((c->c_iflags & (CALLOUT_DFRMIGRATION | CALLOUT_PENDING)) ==
(CALLOUT_DFRMIGRATION | CALLOUT_PENDING) &&
c->c_iflags &= ~CALLOUT_PENDING;
if ((c->c_iflags & CALLOUT_PENDING) == 0) {
c->c_iflags &= ~CALLOUT_PENDING;
c->c_iflags |= CALLOUT_PENDING;
KASSERT((c->c_iflags & CALLOUT_PENDING) == CALLOUT_PENDING,
c->c_iflags &= ~CALLOUT_PENDING;
#define callout_pending(c) ((c)->c_iflags & CALLOUT_PENDING)