Module: Enumerable

Defined in:
lib/threadify.rb

Instance Method Summary collapse

Instance Method Details

#threadify(opts = {}, &block) ⇒ Object 



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# File 'lib/threadify.rb', line 19

def threadify(opts = {}, &block)
# setup
#
  opts = {:threads => opts} if Numeric === opts
  threads = Integer(opts[:threads] || opts['threads'] || Threadify.threads)
  done = Object.new.freeze
  nothing = done
  #jobs = Array.new(threads).map{ Queue.new }
  jobs = Array.new(threads).map{ [] }
  top = Thread.current

# produce jobs
#
  i = 0
  each{|*args| jobs[i % threads].push([args, i]); i += 1}
  threads.times{|i| jobs[i].push(done)}

# setup consumer list
#
  consumers = Array.new threads 

# setup support for short-circuit bailout via 'throw :threadify'
#
  thrownv = Hash.new
  thrownq = Queue.new

  caught = false

  catcher = Thread.new do
    loop do
      thrown = thrownq.pop
      break if thrown == done
      i, thrown = thrown
      thrownv[i] = thrown
      caught = true
    end
  end

# fire off the consumers
#
  threads.times do |i|
    consumers[i] = Thread.new(jobs[i]) do |jobsi|
      this = Thread.current
      this.abort_on_exception = Threadify.abort_on_exception
  
      job = nil

      thrown =
        catch(:threadify) do
          loop{
            break if caught
            #job = jobsi.pop
            job = jobsi.shift
            break if job == done
            args = job.first
            jobsi << (job << block.call(*args))
          }
          nothing
        end


      unless nothing == thrown
        args, i = job
        thrownq.push [i, thrown]
      end
    end
  end

# wait for consumers to finish
#
  consumers.map{|t| t.join}

# nuke the catcher
#
  thrownq.push done
  catcher.join

# iff something(s) was thrown return the one which would have been thrown
# earliest in non-parallel execution
#
  unless thrownv.empty?
    key = thrownv.keys.sort.first
    return thrownv[key]
  end

# collect the results and return them
#
  ret = []
  jobs.each do |results|
    results.each do |result|
      break if result == done
      elem, i, value = result
      ret[i] = value
    end
  end
  ret
end