Kernel-based publish-subscribe system
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BSD_3-Clause_License.txt
LICENSE
Makefile
README.md
fanout.c

README.md

/dev/fanout

Kernel-based publish-subscribe system

WHAT:

  • simple, efficient, broadcast IPC, or alternatively
  • simple, efficient, publish-subscribe IPC
  • kernel module implementing a character device

WHY:

  • Twice as efficient: Only N writes for N subscribers compared to 2* N writes for a sockets based system
  • Simple: Kernel based, no need for a new process or daemon
  • Simple: Use mknod to create a channel or topic as a device node
  • Simple: API is just open()/read()/write()/close()
  • Simple: Works with select() for event driven programming
  • Simple: Works with ALL programming languages, even Bash
  • Simple: No dependencies and no libraries to install
  • Simple: Builds on all Linux systems
  • Secure: Access rights tied to filesystem permissions on device node

INSTALLATION:

sudo apt-get install linux-headers-`uname -r`
git clone --depth=1 https://github.com/bob-linuxtoys/fanout
cd fanout
make
sudo make install

TEST:

sudo modprobe fanout   # load the kernel module

# Get fanout driver's major number to create device node
FANOUTMAJOR=`grep fanout /proc/devices | awk '{print $1}'`
sudo mknod /dev/fanouttest c $FANOUTMAJOR 0
sudo chmod 666 /dev/fanouttest

# Add three subscribers to the topic on /dev/fanouttest
cat /dev/fanouttest &
cat /dev/fanouttest &
cat /dev/fanouttest &

# Publish a messagte to fanouttest topic

echo “Hello, World” > /dev/fanouttest

NOTES:

See http://linustoys.org for an article on fanout.

See Linux Journal of August, 2010 for another article

See also http://github.org/bob-linuxtoys/proxy

COPYRIGHT

Copyright 2010-2015, Bob Smith

LICENSE:

At your discretion, you may consider this software covered by either the GNU Public License, Version 2, or the BSD 3-Clause license. http://opensource.org/licenses/GPL-2.0 http://opensource.org/licenses/BSD-3-Clause