1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
-- scheduler.lua
-- Implementation of a Railway time schedule queue
-- In contrast to the LuaATC interrupt queue, this one can handle many different
-- event receivers. This is done by registering a callback with the scheduler
local ln = advtrains.lines
local sched = {}
local UNITS_THRESH = 10
local MAX_PER_ITER = 10
local callbacks = {}
-- Register a handler callback to handle scheduler items.
-- e - a handler identifier (corresponds to "handler" in enqueue() )
-- func - a function(evtdata) to be executed when a schedule item expires
-- evtdata - arbitrary data that has been passed into enqueue()
function sched.register_callback(e, func)
callbacks[e] = func
end
--[[
{
t = <railway time in seconds>
e = <handler callback>
d = <data table>
u = <unit identifier>
}
The "unit identifier" is there to prevent schedule overflows. It can be, for example, the position hash
of a node or a train ID. If the number of schedules for a unit exceeds UNITS_THRESH, further schedules are
blocked.
]]--
local queue = {}
local units_cnt = {}
function sched.load(data)
if data then
for i,elem in ipairs(data) do
table.insert(queue, elem)
units_cnt[elem.u] = (units_cnt[elem.u] or 0) + 1
end
atlog("[lines][scheduler] Loaded the schedule queue,",#data,"items.")
end
end
function sched.save()
return queue
end
function sched.run()
local ctime = ln.rwt.get_time()
local cnt = 0
local ucn, elem
while cnt <= MAX_PER_ITER do
elem = queue[1]
if elem and elem.t <= ctime then
table.remove(queue, 1)
if callbacks[elem.e] then
-- run it
callbacks[elem.e](elem.d)
else
atwarn("[lines][scheduler] No callback to handle schedule",elem)
end
cnt=cnt+1
ucn = units_cnt[elem.u]
if ucn and ucn>0 then
units_cnt[elem.u] = ucn - 1
end
else
break
end
end
end
-- Enqueue a new scheduled item to be executed at "rwtime"
-- handler: a string identifying the handler to use (registered with sched.register_callback())
-- evtdata: Arbitrary Lua data to be passed to the handler callback
-- unitid: An arbitrary string uniquely identifying the thing that is issuing this enqueue.
-- 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)
assert(type(handler)=="string")
assert(type(unitid)=="string")
assert(type(unitlim)=="number")
local cnt=1
local ucn, elem
ucn = (units_cnt[unitid] or 0)
local ulim=(unitlim or UNITS_THRESH)
if ucn >= ulim then
atwarn("[lines][scheduler] discarding enqueue for",handler,"(limit",ulim,") because unit",unitid,"has already",ucn,"schedules enqueued")
return false
end
while true do
elem = queue[cnt]
if not elem or elem.t > qtime then
table.insert(queue, cnt, {
t=qtime,
e=handler,
d=evtdata,
u=unitid,
})
units_cnt[unitid] = ucn + 1
return true
end
cnt = cnt+1
end
end
-- See enqueue(). Same meaning, except that rwtime is relative to now.
function sched.enqueue_in(rwtime, handler, evtdata, unitid, unitlim)
local ctime = ln.rwt.get_time()
sched.enqueue(ctime + rwtime, handler, evtdata, unitid, unitlim)
end
-- Discards all schedules for unit "unitid" (removes them from the queue)
function sched.discard_all(unitid)
for i=1,#queue do
if queue[i].u == unitid then
table.remove(queue,i)
i=i-1
end
end
units_cnt[unitid] = 0
end
ln.sched = sched
|
