blob: 2af8d156b125caac6a2a6d5f8013fc9bb0d2517f (
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
|
-- | Check that large objects are properly accounted for by GHC.Stats
module Main (main) where
import Control.Monad
import Control.Exception
import Control.Concurrent
import System.Mem
import System.Exit
import GHC.Stats
import GHC.Compact
import Data.List (replicate)
import qualified Data.ByteString.Char8 as BS
doGC :: IO ()
doGC = do
performMajorGC
threadDelay 1000 -- small delay to allow GC to run when using concurrent gc
main :: IO ()
main = do
let size = 4096*2
largeString <- evaluate $ BS.replicate size 'A'
compactString <- compact $ replicate size 'A'
doGC
doGC -- run GC twice to make sure the objects end up in the oldest gen
stats <- getRTSStats
let large_obj_bytes = gcdetails_large_objects_bytes $ gc stats
let compact_obj_bytes = gcdetails_compact_bytes $ gc stats
-- assert that large_obj_bytes is at least as big as size
-- this indicates that `largeString` is being accounted for by the stats department
when (large_obj_bytes < fromIntegral size) $ do
putStrLn $ "large_obj_bytes is: " <> show large_obj_bytes <> " but expected at least: " <> show size
exitFailure
when (compact_obj_bytes < fromIntegral size) $ do
putStrLn $ "compact_obj_bytes is: " <> show large_obj_bytes <> " but expected at least: " <> show size
exitFailure
-- keep them alive
print $ BS.length largeString
print $ length $ getCompact compactString
|
