From: Ruby Quiz <james@...>
Date: 2007-08-17T22:15:37+09:00
Subject: [QUIZ] Process Rings (#135)

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I recently wrote about a challenge in the Programming Erlang book on my blog:

	http://blog.grayproductions.net/articles/2007/08/13/erlang-message-passing

Language comparison issues aside, just figuring out how to build a ring of
"processes" was quite the brain bender for me.  That always makes for good Ruby
Quiz material, in my opinion.

The task is straight forward:

	1. Your program should take two command-line arguments:  a number of
	   processes and a number of cycles.
	2. Begin by creating the requested number of processes, in a ring.
	   For example, when three processes are requested, process one
	   creates and sends messages to process two, which creates and sends
	   messages to process three.  The third process then sends its
	   messages back to process one.
	3. Pass a message around your ring of processes a number of times
	   equal to the requested cycles.  Print timing results for how
	   long this takes.

The message you pass doesn't much matter.  A simple String is fine.  You may
also wish to pass a counter with it, to verify the correct number of sends.

I'll leave the definition of "processes" intentionally vague.  Ruby doesn't have
an equivalent to Erlang processes so we will just say that each process should
represent a node where we could run some instructions concurrently.  Be
creative.