Control.Concurrent.CHP.Channels

The module containing all the different types of channels in CHP.

A communication in CHP is always synchronised: the writer must wait until the reader arrives to take the data. There is thus no automatic or underlying buffering of data. (If you want to use buffers, see the Control.Concurrent.CHP.Buffers module in the chp-plus package).

If it helps, a channel communication can be thought of as a distributed binding. Imagine you have a process that creates a channel and then becomes the parallel composition of two sub-processes that at some point communicate on that channel (formatted here as two columns for illustration):

 do                      c <- oneToOneChannel
                                    (<||>)
    do p                                   do p'
       q                                      y <- q'
       x <- readChannel (reader c)            writeChannel (writer c) y
       r                                      r'
       s x                                    s'

It is as if, at the point where the two processes want to communicate, they come together and directly bind the value from one process in the other:

 do                      c <- oneToOneChannel
                                    (<||>)
    do p                                   do p'
       q                                      y <- q'
       x                            <-        return y
       r                                      r'
       s x                                    s'

The Control.Concurrent.CHP.Channels.Creation contains functions relating to the creation of channels. Channels are used via their ends -- see the Control.Concurrent.CHP.Channels.Ends module, and the Control.Concurrent.CHP.Channels.Communication module.

Broadcast and reduce channels are available in the Control.Concurrent.CHP.Channels.BroadcastReduce module, which is not automatically re-exported here.

This module was split into several smaller modules in version 1.5.0. Since it re-exports all the new modules, your code should not be affected at all.

Channel Creation and Types

module Control.Concurrent.CHP.Channels.Creation

getChannelIdentifier :: Chan r w a -> Unique

Gets the channel's identifier. Useful if you need to be able to identify a channel in the trace later on.

Channel-Ends

module Control.Concurrent.CHP.Channels.Ends

Reading and Writing with Channels

module Control.Concurrent.CHP.Channels.Communication

Useful Type and Function Synonyms

module Control.Concurrent.CHP.Channels.Synonyms