monad-par-0.3.4.8: A library for parallel programming based on a monad

Safe Haskell None Haskell98

Control.Monad.Par.Scheds.TraceInternal

Description

This module exposes the internals of the Par monad so that you can build your own scheduler or other extensions. Do not use this module for purposes other than extending the Par monad with new functionality.

Synopsis

# Documentation

data Trace #

Constructors

 Get (IVar a) (a -> Trace) Put (IVar a) a Trace New (IVarContents a) (IVar a -> Trace) Fork Trace Trace Done Yield Trace LiftIO (IO a) (a -> Trace)

data Sched #

Constructors

 Sched Fieldsno :: !Int workpool :: IORef [Trace] idle :: IORef [MVar Bool] scheds :: [Sched]

newtype Par a #

Constructors

 Par FieldsrunCont :: (a -> Trace) -> Trace

Instances

 # Methods(>>=) :: Par a -> (a -> Par b) -> Par b #(>>) :: Par a -> Par b -> Par b #return :: a -> Par a #fail :: String -> Par a # # Methodsfmap :: (a -> b) -> Par a -> Par b #(<\$) :: a -> Par b -> Par a # # Methodspure :: a -> Par a #(<*>) :: Par (a -> b) -> Par a -> Par b #(*>) :: Par a -> Par b -> Par b #(<*) :: Par a -> Par b -> Par a #

newtype IVar a #

Constructors

 IVar (IORef (IVarContents a))

Instances

 # Methodsspawn :: NFData a => ParIO a -> ParIO (IVar a) #spawn_ :: ParIO a -> ParIO (IVar a) #get :: IVar a -> ParIO a #spawnP :: NFData a => a -> ParIO (IVar a) # # Methodsfork :: ParIO () -> ParIO () #new :: ParIO (IVar a) #put :: NFData a => IVar a -> a -> ParIO () #put_ :: IVar a -> a -> ParIO () #newFull :: NFData a => a -> ParIO (IVar a) #newFull_ :: a -> ParIO (IVar a) # Eq (IVar a) # Equality for IVars is physical equality, as with other reference types. Methods(==) :: IVar a -> IVar a -> Bool #(/=) :: IVar a -> IVar a -> Bool # NFData (IVar a) # Methodsrnf :: IVar a -> () #

data IVarContents a #

Constructors

 Full a Empty Blocked [a -> Trace]

sched :: Bool -> Sched -> Trace -> IO () #

The main scheduler loop.

runPar :: Par a -> a #

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 #

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.

runParAsync :: Par a -> a #

An asynchronous version in which the main thread of control in a Par computation can return while forked computations still run in the background.

new :: Par (IVar a) #

Creates a new IVar

newFull :: NFData a => a -> Par (IVar a) #

Creates a new IVar that contains a value

newFull_ :: a -> Par (IVar a) #

Creates a new IVar that contains a value (head-strict only)

get :: IVar a -> Par a #

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_ :: IVar a -> a -> Par () #

Like put, but only head-strict rather than fully-strict.

put :: NFData a => IVar a -> a -> Par () #

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_.

pollIVar :: IVar a -> IO (Maybe a) #

yield :: Par () #

Allows other parallel computations to progress. (should not be necessary in most cases).