From d3f0299b7e86e27442adf42dcf6a760250b6dd71 Mon Sep 17 00:00:00 2001
From: vivek-shankar <vivek-shankar.varadharajan@polymtl.ca>
Date: Wed, 11 Jul 2018 23:18:35 -0400
Subject: [PATCH] adapted syc algo to robots

---
 buzz_scripts/include/act/barrier.bzz |  2 +-
 buzz_scripts/include/timesync.bzz    | 85 +++++++++++++++-------------
 2 files changed, 47 insertions(+), 40 deletions(-)

diff --git a/buzz_scripts/include/act/barrier.bzz b/buzz_scripts/include/act/barrier.bzz
index d7e141c..1a08ac4 100644
--- a/buzz_scripts/include/act/barrier.bzz
+++ b/buzz_scripts/include/act/barrier.bzz
@@ -67,7 +67,7 @@ function barrier_wait(threshold, transf, resumef, bc) {
     barrier = nil
     timeW = 0
     BVMSTATE = resumef
-  } else if(timeW % 10 == 0 and bc > 0)
+  } else if(timeW % 50 == 0 and bc > 0)
     neighbors.broadcast("cmd", bc)
 
   timeW = timeW+1
diff --git a/buzz_scripts/include/timesync.bzz b/buzz_scripts/include/timesync.bzz
index c441bf5..f190457 100644
--- a/buzz_scripts/include/timesync.bzz
+++ b/buzz_scripts/include/timesync.bzz
@@ -5,7 +5,8 @@ logical_time = 0
 # sync algo. constants
 TIME_JUMP_THR = 5 
 TIME_TO_FORGET = 20
-TIME_TO_SYNC = 100
+TIME_TO_SYNC = 200
+COM_DELAY = 3
 # table to store neighbor time data
 time_nei_table = {}
 # Algo. global parameters
@@ -18,20 +19,23 @@ sync_timer = 0
 function init_time_sync(){
 	neighbors.listen("time_sync",
 		function(vid, value, rid) {
-			log(" TIME SYNC Got (", vid, ",", value, ") #", rid)
-			var msg = string.split(value,",")
-			var msg_time = string.toint(msg[0])
-			var msg_max = string.toint(msg[1])
-			#log("msg:  1: ", msg_time, " 2: ", msg_max )
-			diffMaxLogical = math.max(diffMaxLogical,msg_max-logical_time)
-			var time_offset = msg_time - logical_time
-			if(math.abs(time_offset) > math.abs(syncError)) syncError = time_offset
-			if(time_offset > TIME_JUMP_THR){
-				logical_time = logical_time + time_offset
-				diffMaxLogical = math.max(diffMaxLogical-time_offset,0)
-				jumped = 1
+			if(value != nil){
+				log(" TIME SYNC Got (", vid, ",", value.time , " , ", value.max, ") #", rid)
+				var msg_time = value.time
+				var msg_max = value.max
+				#log("msg:  1: ", msg_time, " 2: ", msg_max )
+				if(msg_time != nil and msg_max != nil){
+					diffMaxLogical = math.max(diffMaxLogical,msg_max-logical_time)
+					var time_offset = msg_time - logical_time
+					if(math.abs(time_offset) > math.abs(syncError)) syncError = time_offset
+					if(time_offset > TIME_JUMP_THR){
+						logical_time = logical_time + time_offset
+						diffMaxLogical = math.max(diffMaxLogical-time_offset,0)
+						jumped = 1
+					}
+					time_nei_table[rid] = { .time=msg_time, .age=0, .max=msg_max} 
+				}
 			}
-			time_nei_table[rid] = { .time=msg_time, .age=0, .max=msg_max}  
 		}
 	)
 }
@@ -44,36 +48,39 @@ function step_time_sync(){
 		log(" SYNC ALGO ACTIVE time:", sync_timer)
 		cnt = 0
 		avg_offset = 0
-	  	foreach(time_nei_table, function(key, value) {
-	    	if(value != nil){
-	    		#log("ForEach neigh : id ", key, " time ", value.time, " , age ", value.age, " , diffmax ", value.max)
-	    		var local_offset = value.time - logical_time - value.age
-	    		if(local_offset > 0){
-	    			avg_offset = avg_offset + 1 * local_offset
-	    			cnt = cnt + 1
-	    		}
-	    		else{
-	    			if(math.abs(local_offset)<TIME_JUMP_THR){
-	    				avg_offset = avg_offset + local_offset
-	    				cnt = cnt + 1
-	    			}
-	    		}
+		if(size(time_nei_table) > 0){
+		  	foreach(time_nei_table, function(key, value) {
+		    	if(value.time != 0){
+		    		#log("ForEach neigh : id ", key, " time ", value.time, " , age ", value.age, " , diffmax ", value.max)
+		    		var local_offset = value.time - logical_time - value.age
+		    		if(local_offset > 0){
+		    			avg_offset = avg_offset + 1 * local_offset
+		    			cnt = cnt + 1
+		    		}
+		    		else{
+		    			if(math.abs(local_offset)<TIME_JUMP_THR){
+		    				avg_offset = avg_offset + local_offset
+		    				cnt = cnt + 1
+		    			}
+		    		}
 
-		    	if(value.age > TIME_TO_FORGET)
-		    		time_nei_table[key] = nil
-		    	value.age = value.age + 1
+			    	if(value.age > TIME_TO_FORGET)
+			    		value.time = 0
+
+			    	value.age = value.age + 1
+			    }
+		    })
+		    if(cnt > 0 and jumped != 1){
+		    	var correction = math.ceil(avg_offset / (cnt + 1) )
+		    	if(math.abs(correction) < TIME_JUMP_THR){
+		    		logical_time = logical_time + correction
+		    	}
 		    }
-	    })
-	    if(cnt > 0 and jumped != 1){
-	    	var correction = math.ceil(avg_offset / (cnt + 1) )
-	    	if(math.abs(correction) < TIME_JUMP_THR){
-	    		logical_time = logical_time + correction
-	    	}
 	    }
-	    
 	    jumped = 0
 	    syncError=0
-	    var mstr =  string.concat(string.tostring(logical_time + 1),",",string.tostring(logical_time + 1 + diffMaxLogical))
+	    var mstr = {.time = (logical_time + COM_DELAY) , .max = (logical_time + COM_DELAY + diffMaxLogical) }
+	    #string.concat(string.tostring(logical_time + 1),",",string.tostring(logical_time + 1 + diffMaxLogical))
 	    neighbors.broadcast("time_sync",mstr)
 	}
 	log("Logical time now ", logical_time)