Ruby implementation work.

bin/threads.rb

@@ -0,0 +1,31 @@
+#!/usr/bin/env ruby
+#
+# A brief demonstration of the inherent problem of running multiple threads
+# on modern SMP (Semetric Multi-Processing, aka multi-core) machines.
+#
+# This will only native threads in Ruby 1.9, but only run on one CPU core
+# due to the stupid Global Interpreter Lock (GIL). Use a tool such as
+# Activity Monitor.app (OS X), `top' (Linux) or Task Manager (Windows)
+# to see the CPU usage of this script during execution.
+#
+# See: http://yehudakatz.com/2010/08/14/threads-in-ruby-enough-already/
+#
+# Author: Preston Lee
+
+THREADS = 8
+
+puts "Creating #{THREADS} worker threads."
+threads = []
+(1..THREADS).each do |n|
+	threads << Thread.new(n) do |n|
+		# Do some long-running computation here...
+		(1..1e7.to_i).each do |x|
+			Math::PI * x # Math is fun.. or something!
+		end
+	end
+end
+
+puts "Waiting for workers to finish."
+threads.each do |t| t.join end
+
+puts "Done!"