wxRuby application with Ruby threads

If you tried to run a wxRuby GUI application with other Ruby threads, you noticed that the wxRuby event loop is greedy, and renders the other threads very slow. Especially, if you do IO operations, file management in the other thread.

The problem is not wxRuby specific, you see the same behavior using other GUI toolkits – so I read it. The reason is that the Ruby thread scheduler can not interrupt external programs the same way it interrupts Ruby threads.

The suggested approach is to use a Wx::Timer in your main thread – the GUI thread – to periodically instruct the scheduler to activate other threads.

While various other sources suggest the following code

timer = Timer.new(self)
evt_timer(timer.id) do
  Thread.pass
end
timer.start(100)

it was not optimal in my case – still very slow.

I tried to run the timer with a 1ms interval

timer = Timer.new(self)
evt_timer(timer.id) do
  Thread.pass
end
timer.start(1)

still not good.

So – and here is what I suggest you do -, I ended up using a sleep in the timer event, and giving explicit, bigger time slots to my IO intensive thread.

timer = Timer.new(self)
evt_timer(timer.id) do
  sleep 0.01
end
timer.start(10)

The 0.01 (seconds sleep time) and the 10 (milliseconds interval) in my case are arbitrary numbers, you need to fine tune them based on your application and user experience. But, it helped big time for my application.

Related Posts

• Ruby 1.9.1 character encoding, Regular Expressions and Ruby on Rails
• A smart Winamp play-list - the implementation
• Surprising element in design
• Compiling Ruby with MinGW
• Ruby 1.9 debugger