blob: d2e1454f31837f58194bc6677fa0786a50a85283 (
plain)
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
|
+(ns scheduled-agent
(:import java.util.concurrent.Executors
java.util.concurrent.TimeUnit)
(:use clojure.stacktrace))
; This is starting to get less agent-like
(defn- runnable-proxy [f]
(proxy [Runnable] [] (run [] (f))))
(defn scheduled-agent
[func period init]
(let [pool (Executors/newScheduledThreadPool 1)
data (ref init)
pfunc (runnable-proxy (fn []
(try
(let [val (func)]
(dosync (ref-set data val)))
(catch Exception e
(print-stack-trace e 5)))))]
{:pool pool
:data data
:future (ref nil)
:func func
:pfunc pfunc
:period period
:init init}))
(defn poll [{d :data}]
"Return current contents of agent."
@d)
(defn start! [{f :future pfunc :pfunc period :period pool :pool}]
(dosync
(if (nil? (ensure f))
(ref-set f (.scheduleWithFixedDelay pool pfunc 0 period TimeUnit/SECONDS)))))
(defn cancel! [{f :future}]
"Cancel automatic updating of agent data. Cannot be restarted."
(if @f
(.cancel @f false)))
(defn update! [{func :func data :data}]
"Synchronously update contents of agent."
(let [val (func)]
(dosync
(ref-set data val))))
|
