This cleans up the timers code in TCP to start using the new

async_drain functionality. This as been tested in NF as well as
by Verisign. Still to do in here is to remove all the old flags. They
are currently left being maintained but probably are no longer needed.

Sponsored by:	Netflix Inc.
Differential Revision:	http://reviews.freebsd.org/D5924

1 files changed, 4 insertions, 18 deletions

diff --git a/sys/netinet/tcp_timer.c b/sys/netinet/tcp_timer.c
index 172c39419739..5d6865c6bf4d 100644
--- a/sys/netinet/tcp_timer.c
+++ b/sys/netinet/tcp_timer.c
@@ -927,7 +927,6 @@ void
 tcp_timer_stop(struct tcpcb *tp, uint32_t timer_type)
 {
 	struct callout *t_callout;
-	timeout_t *f_callout;
 	uint32_t f_reset;
 
 	tp->t_timers->tt_flags |= TT_STOPPED;
@@ -935,27 +934,22 @@ tcp_timer_stop(struct tcpcb *tp, uint32_t timer_type)
 	switch (timer_type) {
 		case TT_DELACK:
 			t_callout = &tp->t_timers->tt_delack;
-			f_callout = tcp_timer_delack_discard;
 			f_reset = TT_DELACK_RST;
 			break;
 		case TT_REXMT:
 			t_callout = &tp->t_timers->tt_rexmt;
-			f_callout = tcp_timer_rexmt_discard;
 			f_reset = TT_REXMT_RST;
 			break;
 		case TT_PERSIST:
 			t_callout = &tp->t_timers->tt_persist;
-			f_callout = tcp_timer_persist_discard;
 			f_reset = TT_PERSIST_RST;
 			break;
 		case TT_KEEP:
 			t_callout = &tp->t_timers->tt_keep;
-			f_callout = tcp_timer_keep_discard;
 			f_reset = TT_KEEP_RST;
 			break;
 		case TT_2MSL:
 			t_callout = &tp->t_timers->tt_2msl;
-			f_callout = tcp_timer_2msl_discard;
 			f_reset = TT_2MSL_RST;
 			break;
 		default:
@@ -971,21 +965,13 @@ tcp_timer_stop(struct tcpcb *tp, uint32_t timer_type)
 		}
 
 	if (tp->t_timers->tt_flags & timer_type) {
-		if ((callout_stop(t_callout) > 0) &&
-		    (tp->t_timers->tt_flags & f_reset)) {
-			tp->t_timers->tt_flags &= ~(timer_type | f_reset);
-		} else {
+		if (callout_async_drain(t_callout, tcp_timer_discard) == 0) {
 			/*
 			 * Can't stop the callout, defer tcpcb actual deletion
-			 * to the last tcp timer discard callout.
-			 * The TT_STOPPED flag will ensure that no tcp timer
-			 * callouts can be restarted on our behalf, and
-			 * past this point currently running callouts waiting
-			 * on inp lock will return right away after the
-			 * classical check for callout reset/stop events:
-			 * callout_pending() || !callout_active()
+			 * to the last one. We do this using the async drain
+			 * function and incrementing the count in 
 			 */
-			callout_reset(t_callout, 1, f_callout, tp);
+			tp->t_timers->tt_draincnt++;
 		}
 	}
 }