monad-par-0.3.4.7: A library for parallel programming based on a monad

Safe HaskellNone
LanguageHaskell98

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

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

data Sched

Constructors

Sched 

Fields

no :: !Int
 
workpool :: IORef [Trace]
 
idle :: IORef [MVar Bool]
 
scheds :: [Sched]
 

newtype Par a

Constructors

Par 

Fields

runCont :: (a -> Trace) -> Trace
 

newtype IVar a

Constructors

IVar (IORef (IVarContents a)) 

Instances

ParFuture IVar ParIO 
ParIVar IVar ParIO 
Eq (IVar a)

Equality for IVars is physical equality, as with other reference types.

NFData (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

runParIO :: Par a -> IO a

A version that avoids an internal unsafePerformIO for calling contexts that are already in the IO monad.

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 a IVar. The get 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 a 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).