Change the TCP timer system from using the callout system five times

directly to a merged model where only one callout, the next to fire,
is registered.

Instead of callout_reset(9) and callout_stop(9) the new function
tcp_timer_activate() is used which then internally manages the callout.

The single new callout is a mutex callout on inpcb simplifying the
locking a bit.

tcp_timer() is the called function which handles all race conditions
in one place and then dispatches the individual timer functions.

Reviewed by:	rwatson (earlier version)

1 files changed, 16 insertions, 5 deletions

diff --git a/sys/netinet/tcp_timer.h b/sys/netinet/tcp_timer.h
index 8d8742de..1c801ad 100644
--- a/sys/netinet/tcp_timer.h
+++ b/sys/netinet/tcp_timer.h
@@ -128,6 +128,22 @@ static const char *tcptimers[] =
     { "REXMT", "PERSIST", "KEEP", "2MSL" };
 #endif
 
+struct tcp_timer {
+	struct callout	tt_timer;
+	int		tt_nextc;	/* next callout time in time_uptime */
+	int		tt_active;	/* engaged callouts */
+#define TT_DELACK	0x01
+#define TT_REXMT	0x02
+#define TT_PERSIST	0x04
+#define TT_KEEP		0x08
+#define TT_2MSL		0x10
+	int             tt_delack;
+	int             tt_rexmt;
+	int             tt_persist;
+	int             tt_keep;
+	int             tt_2msl;
+};
+
 /*
  * Force a time value to be in a certain range.
  */
@@ -158,15 +174,10 @@ extern int tcp_finwait2_timeout;
 extern int tcp_fast_finwait2_recycle;
 
 void	tcp_timer_init(void);
-void	tcp_timer_2msl(void *xtp);
 struct tcptw *
 	tcp_timer_2msl_tw(int _reuse);		/* XXX temporary */
 void	tcp_timer_2msl_reset(struct tcptw *_tw, int rearm);
 void	tcp_timer_2msl_stop(struct tcptw *_tw);
-void	tcp_timer_keep(void *xtp);
-void	tcp_timer_persist(void *xtp);
-void	tcp_timer_rexmt(void *xtp);
-void	tcp_timer_delack(void *xtp);
 
 #endif /* _KERNEL */