| Copyright | (C) 2014 Merijn Verstraaten |
|---|---|
| License | BSD-style (see the file LICENSE) |
| Maintainer | Merijn Verstraaten <merijn@inconsistent.nl> |
| Stability | experimental |
| Portability | haha |
| Safe Haskell | Trustworthy |
| Language | Haskell2010 |
Control.Concurrent.BroadcastChan
Description
A variation of Control.Concurrent.Chan from base, which allows to the easy
creation of broadcast channels without the space-leaks that may arise from
using dupChan.
The Chan type from Control.Concurrent.Chan
consists of both a read and write end. This presents a problem when one
wants to have a broadcast channel that, at times, has zero listeners. To
write to a Chan there must always be a read end
and this read end will hold ALL messages alive until read.
The simple solution applied in this module is to separate read and write ends. As a result, any messages written to the write end can be immediately garbage collected if there are no active read ends, avoding space leaks.
- data BroadcastChan :: Direction -> * -> *
- type In = In
- type Out = Out
- newBroadcastChan :: IO (BroadcastChan In a)
- writeBChan :: BroadcastChan In a -> a -> IO ()
- readBChan :: BroadcastChan Out a -> IO a
- newBChanListener :: BroadcastChan In a -> IO (BroadcastChan Out a)
Documentation
data BroadcastChan :: Direction -> * -> * Source
The abstract type representing the read or write end of a BroadcastChan.
Instances
| Eq (BroadcastChan i a) |
Alias for the In type from the Direction kind, allows users to write
the 'BroadcastChan In a' type without enabling DataKinds.
Alias for the Out type from the Direction kind, allows users to write
the 'BroadcastChan Out a' type without enabling DataKinds.
newBroadcastChan :: IO (BroadcastChan In a) Source
Creates a new BroadcastChan write end.
writeBChan :: BroadcastChan In a -> a -> IO () Source
Write a value to write end of a BroadcastChan. Any messages written
while there are no live read ends can be immediately garbage collected, thus
avoiding space leaks.
readBChan :: BroadcastChan Out a -> IO a Source
Read the next value from the read end of a BroadcastChan.
newBChanListener :: BroadcastChan In a -> IO (BroadcastChan Out a) Source
Create a new read end for a BroadcastChan. Will receive all messages
written to the channel's write end after the read end's creation.