diff options
| author | Zejun Wu <watashi@fb.com> | 2018-11-22 11:49:51 -0500 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2018-11-22 13:14:01 -0500 |
| commit | f088c2d42aaa38b32482ea8c4324786123835e62 (patch) | |
| tree | b69025c1219faf92f2786943b2b7ff9256ead1d7 /compiler/utils/FastFunctions.hs | |
| parent | 1f74f7dd9ffec3540b9bd74225665dfa1519c46e (diff) | |
| download | haskell-f088c2d42aaa38b32482ea8c4324786123835e62.tar.gz | |
Fix deadlock bug when mkFastStringWith is duplicated
In D5211, we use `withMVar` to guard writes to the same segment, this
is unsafe to be duplicated. It can lead to deadlock if it is only run
partially and `putMVar` is not called after `takeMVar`.
Test Plan:
./validate
We used to see deadlock when building stackage without this fix, and it
no longer happens.
Reviewers: simonmar, bgamari
Reviewed By: simonmar
Subscribers: rwbarton, carter
Differential Revision: https://phabricator.haskell.org/D5349
Diffstat (limited to 'compiler/utils/FastFunctions.hs')
| -rw-r--r-- | compiler/utils/FastFunctions.hs | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/compiler/utils/FastFunctions.hs b/compiler/utils/FastFunctions.hs index be3f3cbee4..9a09bb7b76 100644 --- a/compiler/utils/FastFunctions.hs +++ b/compiler/utils/FastFunctions.hs @@ -15,7 +15,7 @@ import GhcPrelude () import GHC.Exts import GHC.IO (IO(..)) --- Just like unsafePerformIO, but we inline it. +-- Just like unsafeDupablePerformIO, but we inline it. {-# INLINE inlinePerformIO #-} inlinePerformIO :: IO a -> a inlinePerformIO (IO m) = case m realWorld# of (# _, r #) -> r |