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
|
import Debug.QuickCheck
import System.IO.Unsafe
import Control.Concurrent.Chan
import Control.Concurrent
import Control.Monad
data Action = NewChan | ReadChan | WriteChan Int | IsEmptyChan | ReturnInt Int
| ReturnBool Bool
deriving (Eq,Show)
main = do
t <- myThreadId
forkIO (threadDelay 1000000 >> killThread t)
-- just in case we deadlock
testChan
testChan :: IO ()
testChan = do
quickCheck prop_NewIs_NewRet
quickCheck prop_NewWriteIs_NewRet
quickCheck prop_NewWriteRead_NewRet
prop_NewIs_NewRet =
[NewChan,IsEmptyChan] =^ [NewChan,ReturnBool True]
prop_NewWriteIs_NewRet n =
[NewChan,WriteChan n,IsEmptyChan] =^ [NewChan,WriteChan n,ReturnBool False]
prop_NewWriteRead_NewRet n =
[NewChan,WriteChan n,ReadChan] =^ [NewChan,ReturnInt n]
perform :: [Action] -> IO ([Bool],[Int])
perform [] = return ([],[])
perform (a:as) =
case a of
ReturnInt v -> liftM (\(b,l) -> (b,v:l)) (perform as)
ReturnBool v -> liftM (\(b,l) -> (v:b,l)) (perform as)
NewChan -> newChan >>= \chan -> perform' chan as
_ -> error $ "Please use NewChan as first action"
perform' :: Chan Int -> [Action] -> IO ([Bool],[Int])
perform' _ [] = return ([],[])
perform' chan (a:as) =
case a of
ReturnInt v -> liftM (\(b,l) -> (b,v:l)) (perform' chan as)
ReturnBool v -> liftM (\(b,l) -> (v:b,l)) (perform' chan as)
ReadChan -> liftM2 (\v (b,l) -> (b,v:l)) (readChan chan)
(perform' chan as)
WriteChan n -> writeChan chan n >> perform' chan as
IsEmptyChan -> liftM2 (\v (b,l) -> (v:b,l)) (isEmptyChan chan)
(perform' chan as)
_ -> error $ "If you want to use " ++ show a
++ " please use the =^ operator"
actions :: Gen [Action]
actions =
liftM (NewChan:) (actions' 0)
actions' :: Int -> Gen [Action]
actions' contents =
oneof ([return [],
liftM (IsEmptyChan:) (actions' contents),
liftM2 (:) (liftM WriteChan arbitrary) (actions' (contents+1))]
++
if contents==0
then []
else [liftM (ReadChan:) (actions' (contents-1))])
(=^) :: [Action] -> [Action] -> Property
c =^ c' =
forAll (actions' (delta 0 c))
(\suff -> observe c suff == observe c' suff)
where observe x suff = unsafePerformIO (perform (x++suff))
(^=^) :: [Action] -> [Action] -> Property
c ^=^ c' =
forAll actions
(\pref -> forAll (actions' (delta 0 (pref++c)))
(\suff -> observe c pref suff ==
observe c' pref suff))
where observe x pref suff = unsafePerformIO (perform (pref++x++suff))
delta :: Int -> [Action] -> Int
delta i [] = i
delta i (ReturnInt _:as) = delta i as
delta i (ReturnBool _:as) = delta i as
delta _ (NewChan:as) = delta 0 as
delta i (WriteChan _:as) = delta (i+1) as
delta i (ReadChan:as) = delta (if i==0
then error "read on empty Chan"
else i-1) as
delta i (IsEmptyChan:as) = delta i as
|
