From 23ea3ea3b378f5f40422d2c547f001b11dc4bd23 Mon Sep 17 00:00:00 2001
From: Steven Dake <sdake@mvista.com>
Date: Fri, 22 Apr 2005 18:44:20 +0000
Subject: [PATCH] defect 498 - reduce network traffic from merge detection

(Logical change 1.188)


git-svn-id: http://svn.fedorahosted.org/svn/corosync/trunk@622 fd59a12c-fef9-0310-b244-a6a79926bd2f
---
 exec/totemsrp.c | 56 ++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 48 insertions(+), 8 deletions(-)

diff --git a/exec/totemsrp.c b/exec/totemsrp.c
index c74da88e..7295ea88 100644
--- a/exec/totemsrp.c
+++ b/exec/totemsrp.c
@@ -103,6 +103,7 @@ int totemsrp_brake;
 #define TIMEOUT_STATE_GATHER_CONSENSUS	200
 #define TIMEOUT_TOKEN					200
 #define TIMEOUT_TOKEN_RETRANSMIT		45
+#define TIMEOUT_MERGE_DETECT			200
 #define PACKET_SIZE_MAX					2000
 #define FAIL_TO_RECV_CONST				250
 #define SEQNO_UNCHANGED_CONST			20
@@ -193,6 +194,8 @@ static struct memb_ring_id my_old_ring_id;
 
 static int my_aru_count = 0;
 
+static int my_merge_detect_timeout_outstanding = 0;
+
 static int my_last_aru = 0;
 
 static int my_seq_unchanged = 0;
@@ -265,6 +268,8 @@ poll_timer_handle timer_orf_token_timeout = 0;
 
 poll_timer_handle timer_orf_token_retransmit_timeout = 0;
 
+poll_timer_handle timer_merge_detect_timeout = 0;
+
 poll_timer_handle memb_timer_state_gather_join_timeout = 0;
 
 poll_timer_handle memb_timer_state_gather_consensus_timeout = 0;
@@ -848,8 +853,10 @@ void memb_set_print (char *string,
 
 static void timer_function_orf_token_timeout (void *data);
 static void timer_function_token_retransmit_timeout (void *data);
+static void timer_function_merge_detect_timeout (void *data);
 
-void reset_token_retransmit_timeout (void) {
+void reset_token_retransmit_timeout (void)
+{
 			poll_timer_delete (*totemsrp_poll_handle,
 				timer_orf_token_retransmit_timeout);
 			poll_timer_add (*totemsrp_poll_handle, TIMEOUT_TOKEN_RETRANSMIT, 0,
@@ -858,6 +865,21 @@ void reset_token_retransmit_timeout (void) {
 
 }
 
+void start_merge_detect_timeout (void)
+{
+	if (my_merge_detect_timeout_outstanding == 0) {
+		poll_timer_add (*totemsrp_poll_handle, TIMEOUT_MERGE_DETECT, 0,
+			timer_function_merge_detect_timeout, &timer_merge_detect_timeout);
+		my_merge_detect_timeout_outstanding = 1;
+	}
+}
+
+void cancel_merge_detect_timeout (void)
+{
+	poll_timer_delete (*totemsrp_poll_handle, timer_merge_detect_timeout);
+	my_merge_detect_timeout_outstanding = 0;
+}
+
 /*
  * ring_state_* is used to save and restore the sort queue
  * state when a recovery operation fails (and enters gather)
@@ -952,7 +974,7 @@ static void memb_state_consensus_timeout_expired (void)
 
 static int memb_join_message_send (void);
 
-static int memb_merge_detect_send (void);
+static int memb_merge_detect_transmit (void);
 
 /*
  * Timers used for various states of the membership algorithm
@@ -1221,6 +1243,7 @@ static void memb_state_gather_enter (void)
 	 */
 	cancel_token_retransmit_timeout (); // REVIEWED
 	cancel_token_timeout (); // REVIEWED
+	cancel_merge_detect_timeout ();
 
 	memb_consensus_reset ();
 
@@ -2489,6 +2512,22 @@ struct timeval timeval;
 	}
 }
 
+void timer_function_merge_detect_timeout(void *data)
+{
+	my_merge_detect_timeout_outstanding = 0;
+
+	switch (memb_state) {
+	case MEMB_STATE_OPERATIONAL:
+		if (my_ring_id.rep.s_addr == my_id.sin_addr.s_addr) {
+			memb_merge_detect_transmit ();
+		}
+		break;
+	case MEMB_STATE_GATHER:
+	case MEMB_STATE_COMMIT:
+	case MEMB_STATE_RECOVERY:
+		break;
+	}
+}
 
 /*
  * Send orf_token to next member (requires orf_token)
@@ -2728,7 +2767,7 @@ int memb_join_message_send (void)
 	return (res);
 }
 
-static int memb_merge_detect_send (void) 
+static int memb_merge_detect_transmit (void) 
 {
 	struct msghdr msghdr;
 	struct iovec iovec;
@@ -2994,11 +3033,15 @@ if (random () % 100 < 10) {
 		}
 	}
 
+	/*
+	 * Handle merge detection timeout
+	 */
 	if (token_ref->seq == my_last_seq) {
-		my_seq_unchanged++;
+		start_merge_detect_timeout ();
 	} else {
-		my_seq_unchanged = 0;
+		cancel_merge_detect_timeout ();
 	}
+
 	my_last_seq = token_ref->seq;
 
 	assert (bytes_received >= sizeof (struct orf_token));
@@ -3201,9 +3244,6 @@ printf ("I held %0.4f ms\n", ((float)tv_diff.tv_usec) / 100.0);
 			reset_token_timeout (); // REVIEWED
 			if (forward_token == 0) {
 				reset_token_retransmit_timeout (); // REVIEWED
-				if (memb_state == MEMB_STATE_OPERATIONAL) {
-					memb_merge_detect_send ();
-				}
 			}
 
 			token_callbacks_execute (TOTEM_CALLBACK_TOKEN_SENT);