Thread gem

A short lightning talk I gave on the Ruby User Group Berlin in October 2014.

Thread#every with a slight modification can be used as a circuit breaking, self updating cache of an external service.

Find many other goodies for working with threads in the Thread gem by @meh:
https://github.com/meh/ruby-thread

Transcript

1. Threads
2. thread gem by @meh
3. Thread#every
4. do something every n seconds
5. lets implement something relevant
6. class Life! ! def self.why?! ! ! sleep(rand(5))! ! ! raise "" unless give_answer?! ! ! "answer: #{rand(42)}"! ! end! ! ! def self.give_answer?! ! ! rand(2) > 0 ? true : false! ! end! ! end
7. class Life! ! def self.why?! ! ! sleep(rand(5))! ! ! raise "" unless give_answer?! ! ! "answer: #{rand(42)}"! ! end! ! ! def self.give_answer?! ! ! rand(2) > 0 ? true : false! ! end! ! end
8. class Life! ! def self.why?! ! ! sleep(rand(5))! ! ! raise "" unless give_answer?! ! ! "answer: #{rand(42)}"! ! end! ! ! def self.give_answer?! ! ! rand(2) > 0 ? true : false! ! end! ! end
9. Life.why?! !
10. Life.why?! # …waiting…!
11. Life.why?! # …waiting…! # RuntimeError:
12. relaxed life
13. accept nil! as an answer!
14. class RelaxedLife! ! def self.why?! @every ||= Thread.every(60) do! Life.why?! end! @every.gimme_value! || "go have fun"! end! ! end
15. class RelaxedLife! ! def self.why?! @every ||= Thread.every(60) do! Life.why?! end! @every.gimme_value! || "go have fun"! end! ! end
16. require "thread/every"! ! class Thread::Every! ! def gimme_value!! @mutex.synchronize do! @old = true! @value! end! end! ! end
17. require "thread/every"! ! class Thread::Every! ! def gimme_value!! @mutex.synchronize do! @old = true! @value! end! end! ! end
18. require "thread/every"! ! class Thread::Every! ! def gimme_value!! @mutex.synchronize do! @old = true! @value! end! end! ! end
19. RelaxedLife.why?!
20. RelaxedLife.why?! # …waiting…!
21. RelaxedLife.why?! # …waiting…! # => "go have fun"!
22. RelaxedLife.why?! # …waiting…! # => "go have fun"! RelaxedLife.why?! # => 8!
23. RelaxedLife.why?! # …waiting…! # => "go have fun"! RelaxedLife.why?! # => 8! RelaxedLife.why?! # => 8!
24. RelaxedLife.why?! # …waiting…! # => "go have fun"! RelaxedLife.why?! # => 8! RelaxedLife.why?! # => 8! RelaxedLife.why?! # => 41!
25. RelaxedLife.why?! # …waiting…! # => "go have fun"! RelaxedLife.why?! # => 8! RelaxedLife.why?! # => 8! RelaxedLife.why?! # => 41! RelaxedLife.why?! # …
26. now go on and live
27. a relaxed life
28. Lukas @Overbryd
29. thread gem by @meh