Treasure Island - Railsberry 2012 - Krakow. Talk about concurrency in Ruby and JRuby in particular. Ruby is pretty unique among scripting languages in having not only one but six (!) fairly mature runtime environments -- MRI, Rubinius, JRuby, MacRuby, IronRuby and MagLev -- each of them with specific strengths. In this talk I will first give a brief overview of planet Ruby and its continents. Then we will embark together on a journey into the deepest concurrency jungles on Java island, where strange beasts like Kilim, Jetlang and Akka roam. With a little luck, we might even encounter the legendary Disruptor! Using examples taken from actual production JRuby code, I will demonstrate how the power of the JVM plus the rich ecosystem around it are an ideal complement to the expressiveness of Ruby -- and how this killer combination can be used to fully exploit modern multicore hardware. Speakers: Tim Lossen, Patrick Huesler

1. Treasure Island

3. Tour
Guides

6. @tlossen

7. @phuesler

9. “The Free Lunch is Over.”
— Herb Sutter (2005)

11. Concurrency

14. Fin?

16. Concurrency

17. Multi Core

20. Thread
Concurrency

21. !fork()

22. Rubies!!!

23. GIL

24. http://igvita.com/2008/11/13/concurrency-is-a-myth-in-ruby/

25. Ruby MRI 1.8 X
REE 1.8 X
Ruby MRI 1.9 X
IronRuby (✔)
Maglev ?
Rubinius ✔
JRuby ✔
MacRuby ✔

26. JRuby

27. Java Island

28. Multi-Threading

30. Evil?

34. java.util.
concurrent

37. Atomic
Boolean

38. CountDown
Latch

39. Cyclic
Barrier

41. Executor

42. Future

44. Actors

46. Bad Actors

48. and the
nominees are...

50. MRI

51. Better Actors

52. Erlang

53. Scala

54. Rubinius

55. JRuby

56. Frameworks

59. Akka

61. Scala

62. Heavily Inspired
by Erlang

63. Simple
Concurrency

64. Distributed

65. Fault
Tolerant

66. Supervisors

68. Fast

70. Can it be used
with JRuby?

71. Yes*

72. Moarrrrr!!!!

73. STM

90. Evented

91. Disruptor

92. http://martinfowler.com/articles/lmax.html

93. Q&A

94. “There ain’t no such
thing as a free lunch.”
— Robert A. Heinlein
❦

95. Links
• “The Free Lunch Is Over” (Herb Sutter, 2005)
• “Real-World Concurrency” (Bryan Cantrill, Jeff
Bonwick, 2008)
• “Don't Fear the Threads” (David Copeland, 2012)
• “Concurrency is not Parallelism” (Rob Pike, 2012)
• “The LMAX Architecture” (Martin Fowler, 2011)

97. Credits
Ajith Kumar (Flickr)
tontoncopt (Flickr)
Hatem Riahi (Flickr)
Stefanie (Flickr)

98. Credits
Barry Skeates (Flickr)
Hillary White (Flickr)
David Thompson (Flickr)
“Dope Zebra”, Rhett & Link