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| author | David Feuer <david.feuer@gmail.com> | 2020-09-17 16:08:23 -0400 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-09-19 15:51:44 -0400 |
| commit | b26cd86795d86850bfa97aa020d0a46b8ac043da (patch) | |
| tree | 27d2940d6cbf59a9928b564f37a64ee0de57f521 | |
| parent | 885ecd18e084e4e2b15fbc5de0aa5222f2573387 (diff) | |
| download | haskell-b26cd86795d86850bfa97aa020d0a46b8ac043da.tar.gz | |
Unpack the MVar in Compact
The `MVar` lock in `Compact` was unnecessarily lazy, creating an extra indirection and wasting two words. Make it strict.
| -rw-r--r-- | libraries/ghc-compact/GHC/Compact.hs | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/libraries/ghc-compact/GHC/Compact.hs b/libraries/ghc-compact/GHC/Compact.hs index c58b751c51..1f985de1ac 100644 --- a/libraries/ghc-compact/GHC/Compact.hs +++ b/libraries/ghc-compact/GHC/Compact.hs @@ -136,7 +136,7 @@ import GHC.Types -- If compaction encounters any of the above, a 'Control.Exception.CompactionFailed' -- exception will be thrown by the compaction operation. -- -data Compact a = Compact Compact# a (MVar ()) +data Compact a = Compact Compact# a !(MVar ()) -- we can *read* from a Compact without taking a lock, but only -- one thread can be writing to the compact at any given time. -- The MVar here is to enforce mutual exclusion among writers. |