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| author | Sven Tennie <sven.tennie@gmail.com> | 2020-10-31 13:32:38 -0400 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2021-09-23 15:59:38 -0400 |
| commit | 022d9717d06542c2345e27ef018390a9d034a1f1 (patch) | |
| tree | a09d409906ffafc2cea1ce6501f9464e575831f8 | |
| parent | 69b35afd2e11a1cac93e803d6da00c1760b9fa3b (diff) | |
| download | haskell-022d9717d06542c2345e27ef018390a9d034a1f1.tar.gz | |
base: Generalize newStablePtrPrimMVar
Make it polymorphic in the type of the MVar's value. This simple generalization
makes it usable for `MVar a` instead of only `MVar ()` values.
| -rw-r--r-- | libraries/base/GHC/Conc/Sync.hs | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/libraries/base/GHC/Conc/Sync.hs b/libraries/base/GHC/Conc/Sync.hs index c51afb9d83..8bab43b966 100644 --- a/libraries/base/GHC/Conc/Sync.hs +++ b/libraries/base/GHC/Conc/Sync.hs @@ -624,10 +624,10 @@ data PrimMVar -- @hs_try_putmvar()@. The RTS wants a 'StablePtr' to the underlying -- 'MVar#', but a 'StablePtr#' can only refer to lifted types, so we -- have to cheat by coercing. -newStablePtrPrimMVar :: MVar () -> IO (StablePtr PrimMVar) +newStablePtrPrimMVar :: MVar a -> IO (StablePtr PrimMVar) newStablePtrPrimMVar (MVar m) = IO $ \s0 -> case makeStablePtr# (unsafeCoerce# m :: PrimMVar) s0 of - -- Coerce unlifted m :: MVar# RealWorld () + -- Coerce unlifted m :: MVar# RealWorld a -- to lifted PrimMVar -- apparently because mkStablePtr is not representation-polymorphic (# s1, sp #) -> (# s1, StablePtr sp #) |