speculation 0.6.0 → 0.7.0

raw patch · 2 files changed

+22/−28 lines, 2 files

Files

• Control/Concurrent/Speculation.hs +14/−25
• speculation.cabal +8/−3

@@ -15,18 +15,14 @@     , specOnSTM'     , specBySTM     , specBySTM'-    -- * Throw to break out of current speculation-    , SpeculationException     -- * Determining if a closure is evaluated     , unsafeGetTagBits     , unsafeIsEvaluated     ) where  import Control.Concurrent.STM-import Control.Exception (Exception, throw, fromException) import Control.Parallel (par)-import Control.Monad (liftM2)-import Data.Typeable (Typeable)+import Control.Monad (liftM2, unless) import Data.Function (on) import Data.Bits ((.&.)) import Foreign (sizeOf)@@ -76,9 +72,9 @@  -- | 'spec' with a user defined comparison function specBy :: (a -> a -> Bool) -> a -> (a -> b) -> a -> b-specBy cmp g f a+specBy cmp guess f a     | unsafeIsEvaluated a = f a-    | otherwise = specBy' cmp g f a+    | otherwise = specBy' cmp guess f a {-# INLINE specBy #-}  -- | 'spec'' with a user defined comparison function@@ -147,26 +143,22 @@  -- | 'specSTM' using a user defined comparison function specBySTM :: (a -> a -> STM Bool) -> STM a -> (a -> STM b) -> a -> STM b-specBySTM cmp g f a +specBySTM cmp guess f a      | unsafeIsEvaluated a = f a -    | otherwise   = specBySTM' cmp g f a+    | otherwise   = specBySTM' cmp guess f a {-# INLINE specBySTM #-}  -- | 'specSTM'' using a user defined comparison function specBySTM' :: (a -> a -> STM Bool) -> STM a -> (a -> STM b) -> a -> STM b-specBySTM' cmp g f a = a `par` -    let -      try = do-        g' <- g-        result <- f g'-        test <- cmp g' a-        if test-          then return result-          else throw SpeculationException-    in -      try `catchSTM` \e -> case fromException e of-        Just SpeculationException -> f a -- rerun with alternative input-        _ -> throw e                     -- this is a bigger problem+specBySTM' cmp mguess f a = a `par` do+    guess <- mguess+    result <- f guess+    -- rendezvous with a+    matching <- cmp guess a +    unless matching retry +    return result+  `orElse` +    f a  {-# INLINE specBySTM' #-}  -- | @'specBySTM' . 'on' (==)@@@ -178,9 +170,6 @@ specOnSTM' :: Eq c => (a -> STM c) -> STM a -> (a -> STM b) -> a -> STM b specOnSTM' = specBySTM' . on (liftM2 (==)) {-# INLINE specOnSTM' #-}--data SpeculationException = SpeculationException deriving (Show,Eq,Typeable)-instance Exception SpeculationException  -- | Used to inspect tag bits data Box a = Box a

@@ -1,5 +1,5 @@ name:           speculation-version:        0.6.0+version:        0.7.0 license:        BSD3 license-file:   LICENSE author:         Edward A. Kmett@@ -42,13 +42,18 @@  .  'specSTM' provides a similar time table for STM actions, but also rolls back side-effects.  . + /Changes in 0.7.0:/+ .+ * Changed @'throw' 'SpeculationException'@ to 'retry'+ * Removed 'SpeculationException'+ .  /Changes in 0.6.0:/  .- * Upgraded the comparisons used by the STM combinators STM actions, so they can check for other STM side-effects.+ * Upgraded the comparisons used by the STM combinators to STM actions, so they can check other STM state  .  /Changes in 0.5.1:/  . - * Exposed unsafeGetTagBits and unsafeIsEvaluated+ * Exposed 'unsafeGetTagBits' and 'unsafeIsEvaluated'  copyright:          (c) 2010 Edward A. Kmett build-type:         Simple