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[[!meta copyright="Copyright © 2008, 2010 Free Software Foundation, Inc."]]
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# libchannel
*libchannel* was accepted as a project for [[Google_Summer_of_Code|community/gsoc]] (or
just GSoC) in 2007. It was written by Carl Fredrik Hammar who was mentored by
Richard Braun.
## Outline
*libchannel* was intended to be used to cleanly and efficiently
implement *channel* translators that would correspond to character
device files. In other words, translators for input devices, sound,
network and the like.
There are many cases where one wishes to stack translators over one
another. Take networking as an example, you may wish to have a pseudo
network device that balance traffic over two real devices.
The problem with stacking translators this way is that it's
inefficient, for every RPC to the balancer a RPC is made to each of
the real devices. Now a RPC isn't really *that* expensive, but in a
more complex example with more layers the overhead of these RPC's makes
such a stacking infeasible.
However, by using *libchannel* a translator can provide a description
of what it does (i.e. the code and data it uses), which a translator
layered untop can fetch and use directly. Now only strictly required
RPC's needs to be sent.
## Result
By the end of GSoC 2007, *libchannel* had mostly reached the initial
goals. There some code missing, most notably the code for
transferring channels via RPC, but similar code was already present in
*libstore* and can be trivially adapted for *libchannel*. It also
needed more debugging.
Despite these minor deficiencies, the project was considered a
success, never the less.
## Future directions
However, while *libchannel* matched the original specifications. It's
believed that it's too inflexible to make use of in many specific
cases and that a more general solution is desired. While the
discussion isn't over yet, it seems *libchannel* will become a support
library to implement specialized channel libraries, e.g. *libaudio*
and *libnetwork* or similar.
So work on *libchannel* will continue, in one form or another.
# Related
* [*Van Jacobson's network channels*](http://lwn.net/Articles/169961/)
(2006-01-31) by Jonathan Corbet.
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