From: David Flanagan Date: 2007-08-09T08:38:41+09:00 Subject: priorities of newly-created threads Hi, In Ruby 1.8 a newly created thread has the priority of the thread that created it. In Ruby 1.9, newly created threads start at priority 0. I suspect that this is a bug. Here's my test code: t1 = Thread.new { Thread.current.priority = -1 t2 = Thread.new { puts "child thread priority: #{Thread.current.priority}" } t2.join } t1.join And here's the output: $ ruby -v priority.rb ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-linux] child thread priority: -1 $ ruby1.9 -v priority.rb ruby 1.9.0 (2007-08-09 patchlevel 0) [i686-linux] child thread priority: 0