This is a test of the future.cancel(true) method.

future_cancellation_test.rb

#! /usr/bin/env jruby

=begin
$ ./interrupt.rb
Current time: Monday March  4 03/04/2013 21:40:06.304
Scheduled event for 10 seconds from now
f1: Current time: Monday March  4 03/04/2013 21:40:06.341
Cancelling f1
f2: Current time: Monday March  4 03/04/2013 21:40:11.357
Got f1: Current time: Monday March  4 03/04/2013 21:40:11.361
Got f2: Current time: Monday March  4 03/04/2013 21:40:11.362
Sleeping to let other tasks finish before exiting
f0: Current time: Monday March  4 03/04/2013 21:40:16.294
f1: Current time: Monday March  4 03/04/2013 21:40:16.342
=end

import java.lang.InterruptedException
import java.lang.Runnable
import java.util.concurrent.Executors
import java.util.concurrent.TimeUnit

# Get the scheduler
@scheduler = Executors.newScheduledThreadPool(2)
@processor = Executors.newCachedThreadPool()

def delay_event(delay, &block)
  future = @scheduler.schedule(block, delay.to_f * 1000, TimeUnit::MILLISECONDS)
end

def execute(&block)
  future = @processor.java_send :submit, [ Runnable.java_class ], block
end

n = (ARGV.shift || 10).to_i

f0 = delay_event(n) {
  puts "f0: Current time: " + Time.now.strftime("%A %B %e %m/%d/%Y %H:%M:%S.%3N")
}

puts "Current time: " + Time.now.strftime("%A %B %e %m/%d/%Y %H:%M:%S.%3N")
puts "Scheduled event for #{n} seconds from now"

f1 = execute {
  begin
    puts "f1: Current time: " + Time.now.strftime("%A %B %e %m/%d/%Y %H:%M:%S.%3N")
    sleep 10
    puts "f1: Current time: " + Time.now.strftime("%A %B %e %m/%d/%Y %H:%M:%S.%3N")
  rescue InterruptedException => ex
    puts "Interrupted future f1" + Time.now.strftime("%A %B %e %m/%d/%Y %H:%M:%S.%3N")
  end
}

f2 = delay_event(n/2) {
  puts "Cancelling f1"
  puts "f2: Current time: " + Time.now.strftime("%A %B %e %m/%d/%Y %H:%M:%S.%3N")
  f1.cancel(true)
}

f1.get rescue nil
puts "Got f1: Current time: " + Time.now.strftime("%A %B %e %m/%d/%Y %H:%M:%S.%3N")
f2.get rescue nil
puts "Got f2: Current time: " + Time.now.strftime("%A %B %e %m/%d/%Y %H:%M:%S.%3N")

puts "Sleeping to let other tasks finish before exiting"
sleep n * 2
puts "Done sleeping"
exit