{-# LANGUAGE CPP #-}
{-# LANGUAGE MagicHash #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE UnboxedTuples #-}
module Regressions (tests) where
import Control.Exception (evaluate)
import Control.Monad (replicateM)
import Data.Bits (shiftL)
import Data.Hashable (Hashable (..))
import Data.List (delete)
import Data.Maybe (isJust, isNothing)
import GHC.Exts (touch#)
import GHC.IO (IO (..))
import Numeric.Natural (Natural)
import System.Mem (performGC)
import System.Mem.Weak (deRefWeak, mkWeakPtr)
import System.Random (randomIO)
import Test.HUnit (Assertion, assert)
import Test.QuickCheck
import Test.Tasty (TestTree, testGroup)
import Test.Tasty.HUnit (testCase)
import Test.Tasty.QuickCheck (testProperty)
import qualified Data.HashMap.Lazy as HML
import qualified Data.HashMap.Strict as HMS
import qualified Data.HashSet as HS
#if MIN_VERSION_base(4,12,0)
-- nothunks requires base >= 4.12
#define HAVE_NOTHUNKS
import qualified Data.Foldable as Foldable
import NoThunks.Class (noThunksInValues)
#endif
issue32 :: Assertion
issue32 = assert $ isJust $ HMS.lookup 7 m'
where
ns = [0..16] :: [Int]
m = HMS.fromList (zip ns (repeat []))
m' = HMS.delete 10 m
------------------------------------------------------------------------
-- Issue #39
-- First regression
issue39 :: Assertion
issue39 = assert $ hm1 == hm2
where
hm1 = HMS.fromList ([a, b] `zip` [1, 1 :: Int ..])
hm2 = HMS.fromList ([b, a] `zip` [1, 1 :: Int ..])
a = (1, -1) :: (Int, Int)
b = (-1, 1) :: (Int, Int)
-- Second regression
newtype Keys = Keys [Int]
deriving Show
instance Arbitrary Keys where
arbitrary = sized $ \l -> do
pis <- replicateM (l+1) positiveInt
return (Keys $ prefixSum pis)
shrink (Keys ls) =
let l = length ls
in if l == 1
then []
else [ Keys (dropAt i ls) | i <- [0..l-1] ]
positiveInt :: Gen Int
positiveInt = (+1) . abs <$> arbitrary
prefixSum :: [Int] -> [Int]
prefixSum = loop 0
where
loop _ [] = []
loop prefix (l:ls) = let n = l + prefix
in n : loop n ls
dropAt :: Int -> [a] -> [a]
dropAt _ [] = []
dropAt i (l:ls) | i == 0 = ls
| otherwise = l : dropAt (i-1) ls
propEqAfterDelete :: Keys -> Bool
propEqAfterDelete (Keys keys) =
let keyMap = mapFromKeys keys
k = head keys
in HMS.delete k keyMap == mapFromKeys (delete k keys)
mapFromKeys :: [Int] -> HMS.HashMap Int ()
mapFromKeys keys = HMS.fromList (zip keys (repeat ()))
------------------------------------------------------------------------
-- Issue #254
-- Key type that always collides.
newtype KC = KC Int
deriving (Eq, Ord, Show)
instance Hashable KC where
hashWithSalt salt _ = salt
touch :: a -> IO ()
touch a = IO (\s -> (# touch# a s, () #))
-- We want to make sure that old values in the HashMap are evicted when new values are inserted,
-- even if they aren't evaluated. To do that, we use the WeakPtr trick described at
-- http://simonmar.github.io/posts/2018-06-20-Finding-fixing-space-leaks.html.
-- We insert a value named oldV into the HashMap, then insert over it, checking oldV is no longer reachable.
--
-- To make the test robust, it's important that oldV isn't hoisted up to the top or shared.
-- To do that, we generate it randomly.
issue254Lazy :: Assertion
issue254Lazy = do
i :: Int <- randomIO
let oldV = error $ "Should not be evaluated: " ++ show i
weakV <- mkWeakPtr oldV Nothing -- add the ability to test whether oldV is alive
mp <- evaluate $ HML.insert (KC 1) (error "Should not be evaluated") $ HML.fromList [(KC 0, "1"), (KC 1, oldV)]
performGC
res <- deRefWeak weakV -- gives Just if oldV is still alive
touch mp -- makes sure that we didn't GC away the whole HashMap, just oldV
assert $ isNothing res
-- Like issue254Lazy, but using strict HashMap
issue254Strict :: Assertion
issue254Strict = do
i :: Int <- randomIO
let oldV = show i
weakV <- mkWeakPtr oldV Nothing
mp <- evaluate $ HMS.insert (KC 1) "3" $ HMS.fromList [(KC 0, "1"), (KC 1, oldV)]
performGC
res <- deRefWeak weakV
touch mp
assert $ isNothing res
------------------------------------------------------------------------
-- Issue #379
#ifdef HAVE_NOTHUNKS
issue379Union :: Assertion
issue379Union = do
let m0 = HMS.fromList [(KC 1, ()), (KC 2, ())]
let m1 = HMS.fromList [(KC 2, ()), (KC 3, ())]
let u = m0 `HMS.union` m1
mThunkInfo <- noThunksInValues mempty (Foldable.toList u)
assert $ isNothing mThunkInfo
issue379StrictUnionWith :: Assertion
issue379StrictUnionWith = do
let m0 = HMS.fromList [(KC 1, 10), (KC 2, 20 :: Int)]
let m1 = HMS.fromList [(KC 2, 20), (KC 3, 30)]
let u = HMS.unionWith (+) m0 m1
mThunkInfo <- noThunksInValues mempty (Foldable.toList u)
assert $ isNothing mThunkInfo
issue379StrictUnionWithKey :: Assertion
issue379StrictUnionWithKey = do
let m0 = HMS.fromList [(KC 1, 10), (KC 2, 20 :: Int)]
let m1 = HMS.fromList [(KC 2, 20), (KC 3, 30)]
let u = HMS.unionWithKey (\(KC i) v0 v1 -> i + v0 + v1) m0 m1
mThunkInfo <- noThunksInValues mempty (Foldable.toList u)
assert $ isNothing mThunkInfo
#endif
-- Another key type that always collides.
--
-- Note (sjakobi): The KC newtype of Int somehow can't be used to demonstrate
-- the space leak in issue379LazyUnionWith. This type does the trick.
newtype SC = SC String
deriving (Eq, Ord, Show)
instance Hashable SC where
hashWithSalt salt _ = salt
issue379LazyUnionWith :: Assertion
issue379LazyUnionWith = do
i :: Int <- randomIO
let k = SC (show i)
weakK <- mkWeakPtr k Nothing -- add the ability to test whether k is alive
let f :: Int -> Int
f x = error ("Should not be evaluated " ++ show x)
let m = HML.fromList [(SC "1", f 1), (SC "2", f 2), (k, f 3)]
let u = HML.unionWith (+) m m
Just v <- evaluate $ HML.lookup k u
performGC
res <- deRefWeak weakK -- gives Just if k is still alive
touch v -- makes sure that we didn't GC away the combined value
assert $ isNothing res
------------------------------------------------------------------------
-- Issue #381
#ifdef HAVE_NOTHUNKS
issue381mapMaybe :: Assertion
issue381mapMaybe = do
let m0 = HMS.fromList [(KC 1, 10), (KC 2, 20 :: Int)]
let m1 = HMS.mapMaybe (Just . (+ 1)) m0
mThunkInfo <- noThunksInValues mempty (Foldable.toList m1)
assert $ isNothing mThunkInfo
issue381mapMaybeWithKey :: Assertion
issue381mapMaybeWithKey = do
let m0 = HMS.fromList [(KC 1, 10), (KC 2, 20 :: Int)]
let m1 = HMS.mapMaybeWithKey (\(KC k) v -> Just (k + v)) m0
mThunkInfo <- noThunksInValues mempty (Foldable.toList m1)
assert $ isNothing mThunkInfo
#endif
------------------------------------------------------------------------
-- Issue #382
issue382 :: Assertion
issue382 = do
i :: Int <- randomIO
let k = SC (show i)
weakK <- mkWeakPtr k Nothing -- add the ability to test whether k is alive
let f :: Int -> Int -> Int
f x = error ("Should not be evaluated " ++ show x)
let m = HML.fromListWith f [(k, 1), (k, 2)]
Just v <- evaluate $ HML.lookup k m
performGC
res <- deRefWeak weakK -- gives Just if k is still alive
touch v -- makes sure that we didn't GC away the combined value
assert $ isNothing res
------------------------------------------------------------------------
-- Issue #383
#ifdef HAVE_NOTHUNKS
-- Custom Functor to prevent interference from alterF rules
newtype MyIdentity a = MyIdentity a
instance Functor MyIdentity where
fmap f (MyIdentity x) = MyIdentity (f x)
issue383 :: Assertion
issue383 = do
i :: Int <- randomIO
let f Nothing = MyIdentity (Just (fromIntegral @Int @Natural (abs i)))
f Just{} = MyIdentity (error "Impossible")
let (MyIdentity m) = HMS.alterF f () mempty
mThunkInfo <- noThunksInValues mempty (Foldable.toList m)
assert $ isNothing mThunkInfo
#endif
------------------------------------------------------------------------
-- Issue #420
issue420 :: Assertion
issue420 = do
let k1 :: Int = 1 `shiftL` 10
let k2 :: Int = 2 `shiftL` 10
let s0 = HS.fromList [k1, k2]
let s1 = s0 `HS.intersection` s0
assert $ k1 `HS.member` s1
assert $ k2 `HS.member` s1
------------------------------------------------------------------------
-- * Test list
tests :: TestTree
tests = testGroup "Regression tests"
[
testCase "issue32" issue32
, testCase "issue39a" issue39
, testProperty "issue39b" propEqAfterDelete
, testCase "issue254 lazy" issue254Lazy
, testCase "issue254 strict" issue254Strict
, testGroup "issue379"
[ testCase "Lazy.unionWith" issue379LazyUnionWith
#ifdef HAVE_NOTHUNKS
, testCase "union" issue379Union
, testCase "Strict.unionWith" issue379StrictUnionWith
, testCase "Strict.unionWithKey" issue379StrictUnionWithKey
#endif
]
#ifdef HAVE_NOTHUNKS
, testGroup "issue381"
[ testCase "mapMaybe" issue381mapMaybe
, testCase "mapMaybeWithKey" issue381mapMaybeWithKey
]
#endif
, testCase "issue382" issue382
#ifdef HAVE_NOTHUNKS
, testCase "issue383" issue383
#endif
, testCase "issue420" issue420
]