INTRO

‘procrastinate’ does the process handling so you don’t have to. It leaves you to concentrate on what to run when, not orchestration of low level details.

This library will be ideal for quickly scheduling of a lot of long running tasks. You can easily control how many processes are run at any time. Your main thread can continue to do useful work until it accesses the results of the computation, at which point it will wait for the processes to finish.

SYNOPSIS

require 'procrastinate/implicit'

class Worker
  def do_work
    puts "> Starting work in process #{Process.pid}"
    sleep 2
    puts "< Work completed in process #{Process.pid}"
  end
end

worker = Procrastinate.proxy(Worker.new)

10.times do 
  worker.do_work
end

Procrastinate.join

The above example will output something like

> Starting work in process 56144
> Starting work in process 56145
> Starting work in process 56146
> Starting work in process 56147
> Starting work in process 56148
> Starting work in process 56149
< Work completed in process 56144
< Work completed in process 56145
< Work completed in process 56146
< Work completed in process 56147
< Work completed in process 56148
< Work completed in process 56149
> Starting work in process 56150
> Starting work in process 56151
> Starting work in process 56152
> Starting work in process 56153
< Work completed in process 56150
< Work completed in process 56151
< Work completed in process 56152
< Work completed in process 56153

(The output depends on the number of cores your machine has)

COMPATIBILITY

This library runs with MRI Ruby >= 1.9.

Ruby 1.9-p136 users must use this patch: gist.github.com/762807

As a general remark: Interaction with Ruby versions is significant. Please use the latest version available to you, since fork & threading bugs are likely to be fixed there.

KNOWN BUGS

Due to the way we handle signal traps, you cannot start more than one Scheduler. We might allow that in the future.

Also: signal traps interact with other libraries and might cause things to break. This is the real world.

STATUS

We’re still adding features that we believe must be in 1.0. What is there mostly works; Multi-Threading is always a difficult topic and we’re glad to receive bug reports.

Please see the LICENSE file for license information.

© 2010 Kaspar Schiess, Patrick Marchi