Question

Learning to use Ruby Threads for transportability of code between different OS platforms.

The problem is the console is frozen until non_join1 completes which also prevents non_join2 from being started. non_join1 waits at the join command until the threads complete.

The software requires multiple routines running independently. The primary program is a standalone that runs in realtime collecting data. The data collected is written to files. Different programs, using Threads, process the data in parallel. The start/stop and status is controlled from a main console.

What is the best ruby method to launch the separate programs needed to analyze the data files and get status back from the threads?

thanks,
pb

# This is the console that starts up the multiple threads.
#!/usr/bin/ruby

loop do
puts " input a command"
command = gets.chop!
control = case command
    when "1" : "1"
    when "2" : "2"
    end
if control == "1" then 
puts `date`+ "routine 1"
puts `./non_join1.rb`
puts `date` 
end

if control == "2" then 
puts `date` + "routine 2"
`./non_join2.rb`    
end

end


#!/usr/bin/ruby
# Example of worker program 1 used to process data files
#file non_join1.rb
x = Thread.new { sleep 0.1; print "xxxxxxxxx"; print "yyyyyyyyyyy"; print "zzzzzzzzzz" }  
a = Thread.new { print "aaaaaaaaa"; print "bbbbbbbbbb"; sleep 0.1; print "cccccccc" } 
puts " "
(1..10).each {|i| puts i.to_s+" done #{i}"}
x.join
a.join
sleep(30)

#!/usr/bin/ruby
# Example of worker program 2 used to  process data files
#file non_join2.rb
x = Thread.new { sleep 0.1; print "xxxxxxxxx"; print "yyyyyyyyyyy"; print "zzzzzzzzzz" }  
a = Thread.new { print "aaaaaaaaa"; print "bbbbbbbbbb"; sleep 0.1; print "cccccccc" } 
x.join
a.join



$ ./call_ruby.rb 
 input a command
 1
 Sat Feb 18 10:36:43 PST 2012
 routine 1
 aaaaaaaaabbbbbbbbbb 
 1 done 1
 2 done 2
 3 done 3
 4 done 4
 5 done 5
 6 done 6
 7 done 7
 8 done 8
 9 done 9
 10 done 10
 xxxxxxxxxyyyyyyyyyyyzzzzzzzzzzcccccccc
 Sat Feb 18 10:37:13 PST 2012
 input a command

Answer 1

Instead of executing with “ try this forking (creating a new process), using for example this function:

class Execute
  def self.run(command)
    pid = fork do
      Kernel.exec(command)
    end
    return pid
  end  
end

Your code will look like

loop do
  puts " input a command"
  command = gets.chop!
  control = case command
    when "1" : "1"
    when "2" : "2"
  end
  if control == "1" then 
    puts `date`+ "routine 1"
    Execute.run("./non_join1.rb")
    puts `date` 
  end

  if control == "2" then 
    puts `date` + "routine 2"
    Execute.run("./non_join2.rb")
  end

end