* История JRuby; * Платформа JVM и ее возможности; * Почему стоит попробовать JRuby; * Как мы в Хот Спот используем JRuby для разработки; * Сравнение с другими JVM языками.

1. JRuby
Практика применения

2. Short history

3. Short history
• 2001 - the first version of JRuby(by Jan
Arne Petersen)

4. Short history
• 2001 - the first version of JRuby(by Jan
Arne Petersen)
• 2006 - version 0.9.0(by Charles Nutter,
Thomas Enebo, Ola Bini and Nick Siege)

5. Short history
• 2001 - the first version of JRuby(by Jan
Arne Petersen)
• 2006 - version 0.9.0(by Charles Nutter,
Thomas Enebo, Ola Bini and Nick Siege)
• 2007 - version 1.0(passed all Rails tests)

6. Why JRuby?

7. Why JRuby?
• Multithreading

8. Why JRuby?
• Multithreading
• JVM

9. Why JRuby?
• Multithreading
• JVM
• Cross-platform

10. Why JRuby?
• Multithreading
• JVM
• Cross-platform
• Just another .jar

11. Why JRuby?
• Multithreading
• JVM
• Cross-platform
• Just another .jar
• GUI

12. Why JRuby?
• Multithreading
• JVM
• Cross-platform
• Just another .jar
• GUI
• Android

13. JVM

14. JVM
• Concurrent threading

15. JVM
• Concurrent threading
• Garbage collectors

16. JVM
• Concurrent threading
• Garbage collectors
• JIT compiler

17. JVM
• Concurrent threading
• Garbage collectors
• JIT compiler
• invokedynamic(JDK 7)

18. Missing features

19. Missing features
• Memory footprint

20. Missing features
• Memory footprint
• No Kernel#fork

21. Missing features
• Memory footprint
• No Kernel#fork
• No continuations(callcc)

22. Missing features
• Memory footprint
• No Kernel#fork
• No continuations(callcc)
• ObjectSpace off by default(-X+O to enable)

23. Missing features
• Memory footprint
• No Kernel#fork
• No continuations(callcc)
• ObjectSpace off by default(-X+O to enable)
• set_trace_func off by default(--debug to
enable)

24. C extensions
since JRuby 1.6(still experimental)

25. Easy installing
• rvm install jruby
• rbenv install jruby-1.6.6 (*)
• Download from http://jruby.org

26. Compatibilities
Ruby 1.8.7 & 1.9.2 compatible
(default 1.8)
flag `jruby --1.9` for 1.9.2 compatibility

27. Nailgun
(since 1.3.0 version)

28. Nailgun
(since 1.3.0 version)
Nailgun is a client, protocol, and server for
running Java programs in the server.

29. Nailgun
(since 1.3.0 version)
Nailgun is a client, protocol, and server for
running Java programs in the server.
$ jruby --ng-server &
$ jruby --ng -e "puts 1"

30. Multi-VM support
many apps in one process

31. Multi-VM support
many apps in one process
JVM

32. Multi-VM support
many apps in one process
JRuby JRuby JRuby JRuby JRuby
JVM

33. Benchmarks
jruby 1.7.0.dev(JDK 6) jruby 1.7.0.dev(JDK 7) invokedynamic=false
jruby 1.7.0.dev(JDK 7) ruby 1.9.3-p0

34. Benchmarks
jruby 1.7.0.dev(JDK 6) jruby 1.7.0.dev(JDK 7) invokedynamic=false
jruby 1.7.0.dev(JDK 7) ruby 1.9.3-p0
4
3
2
1
0
bench/bench_red_black.rb (sec)

35. Benchmarks
jruby 1.7.0.dev(JDK 6) jruby 1.7.0.dev(JDK 7) invokedynamic=false
jruby 1.7.0.dev(JDK 7) ruby 1.9.3-p0
4
3
2
1
0
bench/bench_red_black.rb (sec)

36. Benchmarks
jruby 1.7.0.dev(JDK 6) jruby 1.7.0.dev(JDK 7) invokedynamic=false
jruby 1.7.0.dev(JDK 7) ruby 1.9.3-p0
4
3
2
1
0
bench/bench_red_black.rb (sec)

37. Benchmarks
jruby 1.7.0.dev(JDK 6) jruby 1.7.0.dev(JDK 7) invokedynamic=false
jruby 1.7.0.dev(JDK 7) ruby 1.9.3-p0
4
3
2
1
0
bench/bench_red_black.rb (sec)

38. Benchmarks
jruby 1.7.0.dev(JDK 6) jruby 1.7.0.dev(JDK 7) invokedynamic=false
jruby 1.7.0.dev(JDK 7) ruby 1.9.3-p0
4
3
2
1
0
bench/bench_red_black.rb (sec)

39. jvisualvm

40. jvisualvm

41. jvisualvm

42. JVM + JRuby

43. JVM + JRuby
• Swing, SWT

44. JVM + JRuby
• Swing, SWT
• JavaFX

45. JVM + JRuby
• Swing, SWT
• JavaFX
• Spring & Hibernate

46. JVM + JRuby
• Swing, SWT
• JavaFX
• Spring & Hibernate
• Scala, Groovy, Jython, Clojure, ...

47. JVM + JRuby
Swing

48. JVM + JRuby
Swing

49. RedCar
SWT

50. Java + Ruby

51. Java + Ruby
• require ‘java’

52. Java + Ruby
• require ‘java’
• Java namespace

53. Java + Ruby
• require ‘java’
• Java namespace
• Snake case(get_some vs getSome)

54. Java + Ruby
• require ‘java’
• Java namespace
• Snake case(get_some vs getSome)
• Ruby-style accessors(length= vs setLength)

55. Java + Ruby
• require ‘java’
• Java namespace
• Snake case(get_some vs getSome)
• Ruby-style accessors(length= vs setLength)
• Converting types

56. Java + Ruby
• require ‘java’
• Java namespace
• Snake case(get_some vs getSome)
• Ruby-style accessors(length= vs setLength)
• Converting types
• Swing IRB(command: jirb_swing)

57. Java bridge
Collections

58. Java bridge
Collections
Java List:
java_list[0]
java_list << 5
java_list += 7

59. Java bridge
Collections
Java List: Java Map:
java_list[0] java_list[‘key’]
java_list << 5 java_list[‘key’] = 5
java_list += 7

60. Java bridge
Collections
Java List: Java Map:
java_list[0] java_list[‘key’]
java_list << 5 java_list[‘key’] = 5
java_list += 7
Ruby List:
[1, 2, 3].to_java :int
[“string”].to_java :string

61. Java bridge
Overloading
Java:
public class Test {
public boolean isSome(String arg) {...}
public boolean isSome(int arg) {...}
public boolean isSome(long arg) {...}
public boolean isSome(Object arg) {...}
}

62. Java bridge
Overloading
Ruby:
Test.new.java_send :isSome, [Java::long], 1_000
or
class Test
java_alias :is_some, :isSome, [Java::long]
...
end

63. Java bridge
Annotations
Java:
@Bean(scope = Scope.PROTOTYPE)
public class Person {
...
}

64. Java bridge
Annotations
Ruby:
java_import Bean
java_import Scope
class Person
end
Person.add_class_annotation(Bean: {
‘scope’ => Scope.PROTOTYPE
})
Person.become_java!

65. Java bridge
Interfaces
Ruby:
class Posts
include java.util.Iterator
end

66. JRuby compiler
Ahead-Of-Time Compilation
$ jrubyc <script name>.rb
$ java -cp .:/path/to/jruby.jar <script name>

67. JRuby compiler
Generate .java classes from .rb
$ jrubyc --java <script name>.rb

68. JRuby compiler
Ruby:
require 'java'
class Vec
def initialize(x, y)
@xcoord = x
@ycoord = y
end
end

69. JRuby compiler
Ruby:
require 'java'
class Vec
java_signature 'Vec(double x, double y)'
def initialize(x, y)
@xcoord = x
@ycoord = y
end
end

70. JRuby compiler
Java:
import org.jruby.Ruby;
import org.jruby.RubyObject;
import org.jruby.RubyClass;
...
public class Vec extends RubyObject {
...
public Vec(double x, double y) {
...
}
}

71. Rake + Ant

72. Rake + Ant
Ant tasks like Rake tasks:
task :ant_import do
ant_import
end

73. Buildr
http://buildr.apache.org
Apache Buildr is a build system for Java-based
applications, including support for Scala, Groovy and a
growing number of JVM languages and tools.

74. Buildr
http://buildr.apache.org

75. Buildr
http://buildr.apache.org
• Projects and sub-projects

76. Buildr
http://buildr.apache.org
• Projects and sub-projects
• Compiling, copying and filtering resources,
test cases, Javadoc and more

77. Buildr
http://buildr.apache.org
• Projects and sub-projects
• Compiling, copying and filtering resources,
test cases, Javadoc and more
• Builds what has changed since the last release

78. Buildr
http://buildr.apache.org
• Projects and sub-projects
• Compiling, copying and filtering resources,
test cases, Javadoc and more
• Builds what has changed since the last release
• Support Maven 2.0

79. Buildr
http://buildr.apache.org
• Projects and sub-projects
• Compiling, copying and filtering resources,
test cases, Javadoc and more
• Builds what has changed since the last release
• Support Maven 2.0
• Support Ant

80. Buildr
http://buildr.apache.org
• Projects and sub-projects
• Compiling, copying and filtering resources,
test cases, Javadoc and more
• Builds what has changed since the last release
• Support Maven 2.0
• Support Ant
• Buildr is Ruby all the way down

81. Buildr
http://buildr.apache.org
buildfile:
repositories.remote "http://repo.typesafe.com/typesafe/releases/"
desc "The Springmongodb project"
define "SpringMongoDB" do
project.version = "0.1"
project.group = "SpringMongoDB"
run.with "org.jruby:jruby-complete:jar:1.6.6",
"org.mongodb:mongo-java-driver:jar:2.7.2",
"org.springframework:spring-core:jar:3.1.0.RELEASE",
"org.springframework:spring-context:jar:3.1.0.RELEASE",
"org.springframework:spring-beans:jar:3.1.0.RELEASE",
'org.springframework.data:spring-data-commons-core:jar:1.1.0.RELEASE',
"org.springframework.data:spring-data-mongodb:jar:1.0.0.RC1"
run.using main: ['org.jruby.Main', _(:src, :main, :ruby, "app.rb")]
end

82. Rawr
http://rawr.rubyforge.org
Rawr, a packaging and deployment tool, that allows turns your
code into an executable jar, a .exe for Windows, and a .app for
OS X.

83. Rawr
http://rawr.rubyforge.org
$ gem install rawr
$ rawr install
...
$ rake rawr:jar

84. Deployment

85. JRuby-Rack
Servlet JRuby-Rack Rack
Rack
container servlet filter application

86. JRuby servers

87. JRuby servers
WEBrick

88. JRuby servers
WEBrick
Trinidad

89. JRuby servers
WEBrick
Trinidad
TorqueBox

90. TorqueBox
http://torquebox.org

91. TorqueBox
http://torquebox.org

92. TorqueBox
http://torquebox.org
Installation:
jruby -S gem install torquebox-server --pre

93. TorqueBox
http://torquebox.org
Usage:
torquebox deploy ~/Projects/rails_app
torquebox run

94. Warbler
Warbler is a gem to make a Java jar or war file
out of any Ruby, Rails, Merb, or Rack application.

95. Warbler
Installation:
jruby -S gem install warbler

96. Warbler
Usage:

97. Warbler

98. Warbler
Standalone application:

99. Tuning flags

100. Tuning flags
• --server - server compiler

101. Tuning flags
• --server - server compiler
• -Xmx - max heap size

102. Tuning flags
• --server - server compiler
• -Xmx - max heap size
• -XX:+UnlockExperimentalVMOptions
-XX:+UseG1GC - new GC(JDK 7)

103. Clouds
• Amazon Elastic Beans(http://aws.amazon.com/
elasticbeanstalk/)
• Jelastic(http://jelastic.com)
• Engine Yard(http://www.engineyard.com)
• Google App Engine(http://
appengine.google.com)

104. Hot Spot

105. Bot Hunter

106. Bot Hunter
• Multithreading

107. Bot Hunter
• Multithreading
• Some logic on Scala

108. Yukihiro Matsumoto: “I would remove the
thread and add actors or some other more
advanced concurrency features”.

109. Akka
http://akka.io/
Simpler Concurrency, Scalability & Fault-
tolerance through Actors
slidesha.re/akka-scala-days-2010

110. Actor Model of
Concurrency
slidesha.re/akka-scala-days-2010

111. Actor Model of
Concurrency
• Implements Message-Passing Concurrency
slidesha.re/akka-scala-days-2010

112. Actor Model of
Concurrency
• Implements Message-Passing Concurrency
• Share nothing
slidesha.re/akka-scala-days-2010

113. Actor Model of
Concurrency
• Implements Message-Passing Concurrency
• Share nothing
• Isolated lightweight process
slidesha.re/akka-scala-days-2010

114. Actor Model of
Concurrency
• Implements Message-Passing Concurrency
• Share nothing
• Isolated lightweight process
• Communicates through messages
slidesha.re/akka-scala-days-2010

115. Actor Model of
Concurrency
• Implements Message-Passing Concurrency
• Share nothing
• Isolated lightweight process
• Communicates through messages
• Asynchronous and non-blocking
slidesha.re/akka-scala-days-2010

116. Actor Model of
Concurrency
• Implements Message-Passing Concurrency
• Share nothing
• Isolated lightweight process
• Communicates through messages
• Asynchronous and non-blocking
• Each actor has a mailbox(message queue)
slidesha.re/akka-scala-days-2010

117. Two different models
slidesha.re/akka-scala-days-2010

118. Two different models
• Thread-based
slidesha.re/akka-scala-days-2010

119. Two different models
• Thread-based
• Event-based
slidesha.re/akka-scala-days-2010

120. Two different models
• Thread-based
• Event-based
• Very lightweight(~300 bytes per actor)
slidesha.re/akka-scala-days-2010

121. Two different models
• Thread-based
• Event-based
• Very lightweight(~300 bytes per actor)
• Can easily create millions on a single
workstation
slidesha.re/akka-scala-days-2010

122. Example
slidesha.re/akka-scala-days-2010

123. Server code
class HelloWorldActor extends UntypedActor {
public void onReceive(Object msg) {
getContext().tryReply(msg + " World");
}
}
remote().start("localhost", 2552).register(
"hello-service",
actorOf(HelloWorldActor.class));
slidesha.re/akka-scala-days-2010

124. Client code
actor = Actors.remote.actorFor(
"hello-service", "localhost", 2552)
res = actor.ask("Hello").get
slidesha.re/akka-scala-days-2010

125. The Bad

126. java.lang.NullPointerException

127. Groovy

128. Questions?
Email: klimtimothy@gmail.com