Function pgdelete

freebsd/kern/kern_proc.c:774–806

* delete a process group */

 * delete a process group
 */
static void
pgdelete(struct pgrp *pgrp)
{
	struct session *savesess;
	struct tty *tp;

	sx_assert(&proctree_lock, SX_XLOCKED);
	PGRP_LOCK_ASSERT(pgrp, MA_NOTOWNED);
	SESS_LOCK_ASSERT(pgrp->pg_session, MA_NOTOWNED);

	/*
	 * Reset any sigio structures pointing to us as a result of
	 * F_SETOWN with our pgid.  The proctree lock ensures that
	 * new sigio structures will not be added after this point.
	 */
	funsetownlst(&pgrp->pg_sigiolst);

	PGRP_LOCK(pgrp);
	tp = pgrp->pg_session->s_ttyp;
	LIST_REMOVE(pgrp, pg_hash);
	savesess = pgrp->pg_session;
	PGRP_UNLOCK(pgrp);

	/* Remove the reference to the pgrp before deallocating it. */
	if (tp != NULL) {
		tty_lock(tp);
		tty_rel_pgrp(tp, pgrp);
	}

	proc_id_clear(PROC_ID_GROUP, pgrp->pg_id);
	uma_zfree(pgrp_zone, pgrp);
	sess_release(savesess);
}


static void