HINet

Interaction Nets in Haskell

Using the fact that the GHC run-time easily handles millions of tiny threads, we produced a highly concurrent implementation of interaction nets in Haskell.

The included interpreter RunInets performs parallel execution of .inet files written in a restricted version of Ian Mackie's “Inets” language, for which so far only a compiler to sequential code has been available in the Inets project. Some example .inet files are included in the HINet distribution.

With the executables RunInets, fibND, and ackND from this package, you can:

• Calculate the 20th Fibonacci number using cascading recursion on 1 core, with 1GB fixed heap:

      time fibND +RTS -N1 -H1G -M1G -RTS 20
  

  Try again with 4 cores:

      time fibND +RTS -N4 -H1G -M1G -RTS 20
  

  Don't be disappointed that the speed-up is far from 4 — HINet only implements extremely fine-grained concurrency without any attempt to achieve larger granularity for parallelisation.
• Get more information from the GHC run-time system:

      time fibND +RTS -N4 -H1G -M1G -s -RTS 20
  

• Calculate Ackerman(3,6):

      time ackND +RTS -N1 -H7M -M7M -RTS 3 6
      time ackND +RTS -N4 -H7M -M7M -RTS 3 6
  

• Give larger arguments according to the time you have — you will see slightly better speed-ups. Consider running htop to see what is happening on your machine...
• Calculate fib(20) again, but using a .inet specification — like the above, this works with unary numbers internally, but now also produces a unary number as output:

      time RunInets +RTS -N1 -H1G -M1G -RTS data/Nat/fib20.inet 
      time RunInets +RTS -N4 -H1G -M1G -RTS data/Nat/fib20.inet 
  

  The conversion can be done in the Inets language, by using int attributes:

      time RunInets +RTS -N1 -H1G -M1G -RTS data/Nat/fibN20.inet 
      time RunInets +RTS -N4 -H1G -M1G -RTS data/Nat/fibN20.inet 
  

• Calculate fib(20) again, but now using an .inet specification that does all the additions on int attributes:

      time RunInets +RTS -N1 -H1G -M1G -RTS data/Inets/fibonacci20.inet
      time RunInets +RTS -N4 -H1G -M1G -RTS data/Inets/fibonacci20.inet
  

• Sort a (fixed) randomly-generated list (which you can inspect in the argument file):

      time RunInets +RTS -N1 -H1G -M1G -RTS data/Inets/sort100.inet 
      time RunInets +RTS -N4 -H1G -M1G -RTS data/Inets/sort100.inet 
  

• Write and RunInets your own .inet files...
• Delve into the (somewhat literate) code listing doc/HINet.pdf and build your own interaction net tools using HINet...

Downloads:

• HINet-0.1.tar.gz