| Safe Haskell | None |
|---|---|
| Language | Haskell98 |
Control.Monad.Par.Scheds.Trace
Contents
Description
This is the scheduler described in the paper "A Monad for
Deterministic Parallelism". It is based on a lazy Trace data
structure that separates the scheduler from the Par monad
method implementations.
Synopsis
- data Par a
- runPar :: Par a -> a
- runParIO :: Par a -> IO a
- fork :: Par () -> Par ()
- data IVar a
- new :: Par (IVar a)
- newFull :: NFData a => a -> Par (IVar a)
- newFull_ :: a -> Par (IVar a)
- get :: IVar a -> Par a
- put :: NFData a => IVar a -> a -> Par ()
- put_ :: IVar a -> a -> Par ()
- spawn :: NFData a => Par a -> Par (IVar a)
- spawn_ :: Par a -> Par (IVar a)
- spawnP :: NFData a => a -> Par (IVar a)
- fixPar :: (a -> Par a) -> Par a
- data FixParException = FixParException
Documentation
Run a parallel, deterministic computation and return its result.
Note: you must NOT return an IVar in the output of the parallel
computation. This is unfortunately not enforced, as it is with
runST or with newer libraries that export a Par monad, such as
lvish.
runParIO :: Par a -> IO a Source #
A version that avoids an internal unsafePerformIO for calling
contexts that are already in the IO monad.
Returning any value containing IVar is still disallowed, as it can compromise type safety.
get :: IVar a -> Par a Source #
Read the value in an IVar. The get operation can only return when the
value has been written by a prior or parallel put to the same
IVar.
put :: NFData a => IVar a -> a -> Par () Source #
Put a value into an IVar. Multiple puts to the same IVar
are not allowed, and result in a runtime error.
put fully evaluates its argument, which therefore must be an
instance of NFData. The idea is that this forces the work to
happen when we expect it, rather than being passed to the consumer
of the IVar and performed later, which often results in less
parallelism than expected.
Sometimes partial strictness is more appropriate: see put_.
fixPar :: (a -> Par a) -> Par a Source #
Take the monadic fixpoint of a Par computation. This is
the definition of mfix for Par. Throws FixParException
if the result is demanded strictly within the computation.
data FixParException Source #
Constructors
| FixParException |
Instances
| Show FixParException Source # | |
Defined in Control.Monad.Par.Scheds.TraceInternal Methods showsPrec :: Int -> FixParException -> ShowS # show :: FixParException -> String # showList :: [FixParException] -> ShowS # | |
| Exception FixParException Source # | |
Defined in Control.Monad.Par.Scheds.TraceInternal Methods toException :: FixParException -> SomeException # | |