Make scheduler aware of time wrapping

2 files changed, 19 insertions, 7 deletions

diff --git a/advtrains_line_automation/railwaytime.lua b/advtrains_line_automation/railwaytime.lua
index ca14ba0..d35bb73 100644
--- a/advtrains_line_automation/railwaytime.lua
+++ b/advtrains_line_automation/railwaytime.lua
@@ -60,6 +60,9 @@ local CYCLE = 24*60*60
 local MODULUS = CYCLE*7
 local MODULUS_H = MODULUS / 2
 
+rwt.CYCLE = CYCLE
+rwt.MODULUS = MODULUS
+
 -- adjust so that it is in range [-MODULUS/2, MODULUS/2)
 local function i_adjust(sec)
 	return ((sec + MODULUS_H) % MODULUS) - MODULUS_H
@@ -146,7 +149,7 @@ end
 
 function rwt.new_i(sign, c, h, m, s)
 	assert(math.abs(sign)==1)
-	assert(c>=0 and c<7 and c==math.floor(c))
+	assert(c>=0 and c<3 and c==math.floor(c)) -- interval may be max. +-3 days to avoid overflow!
 	assert(h>=0 and h<24 and h==math.floor(h))
 	assert(m>=0 and m<60 and m==math.floor(m))
 	assert(s>=0 and s<60)
@@ -228,6 +231,7 @@ function rwt.i_sec(rwint)
 		return res.sign * (res.c*60*60*24 + res.h*60*60 + res.m*60 + res.s)
 	end
 end
+rwt.to_secs = rwt.i_sec -- deprecated alias
 
 -- time to string
 -- fmt:
diff --git a/advtrains_line_automation/scheduler.lua b/advtrains_line_automation/scheduler.lua
index 6025b02..de58b3b 100644
--- a/advtrains_line_automation/scheduler.lua
+++ b/advtrains_line_automation/scheduler.lua
@@ -9,6 +9,15 @@ local sched = {}
 local UNITS_THRESH = 10
 local MAX_PER_ITER = 10
 
+local MODULUS = ln.rwt.MODULUS
+local MODULUS_H = MODULUS / 2
+
+-- true if a > b (mod MODULUS)
+local function gt_mod(a, b)
+	local d = a - b -- d>0 -> a>b
+	return ((d + MODULUS_H) % MODULUS) > MODULUS_H
+end
+
 local callbacks = {}
 
 -- Register a handler callback to handle scheduler items.
@@ -53,7 +62,7 @@ function sched.run()
 	local ucn, elem
 	while cnt <= MAX_PER_ITER do
 		elem = queue[1]
-		if elem and elem.t <= ctime then
+		if elem and not gt_mod(elem.t,ctime) then
 			table.remove(queue, 1)
 			if callbacks[elem.e] then
 				-- run it
@@ -79,7 +88,7 @@ end
 --    used to prevent expotentially growing "scheduler bombs"
 -- unitlim: Custom override for UNITS_THRESH (see there)
 function sched.enqueue(rwtime, handler, evtdata, unitid, unitlim)
-	local qtime = ln.rwt.to_secs(rwtime)
+	local qtime = ln.rwt.t_sec(rwtime)
 	assert(type(handler)=="string")
 	assert(type(unitid)=="string")
 	assert(type(unitlim)=="number")
@@ -96,7 +105,7 @@ function sched.enqueue(rwtime, handler, evtdata, unitid, unitlim)
 	
 	while true do
 		elem = queue[cnt]
-		if not elem or elem.t > qtime then
+		if not elem or gt_mod(elem.t, qtime) then
 			table.insert(queue, cnt, {
 					t=qtime,
 					e=handler,
@@ -111,10 +120,9 @@ function sched.enqueue(rwtime, handler, evtdata, unitid, unitlim)
 end
 
 -- See enqueue(). Same meaning, except that rwtime is relative to now.
-function sched.enqueue_in(rwtime, handler, evtdata, unitid, unitlim)
+function sched.enqueue_in(rwint, handler, evtdata, unitid, unitlim)
 	local ctime = ln.rwt.get_time()
-	local rwtime_s = ln.rwt.to_secs(rwtime)
-	sched.enqueue(ctime + rwtime_s, handler, evtdata, unitid, unitlim)
+	sched.enqueue(ln.rwt.add(ctime, rwint), handler, evtdata, unitid, unitlim)
 end
 
 -- Discards all schedules for unit "unitid" (removes them from the queue)