GracefulShutdown

A tiny helper for handling signals and shutting down your program safely.

This is is the outcome of a series of blog posts about signal handling in Ruby. If you understand the basic techniques involved, you can probably write this library yourself, but it might save you a bit of time. The tests for this library might be of interest to anyone testing signal handlers using RSpec.

There is a top-level method for handling signals, which wraps a block of code. Anything running inside the block can rescue a Shutdown exception and perform any necessary steps for a safe shutdown. Once handled, the continue method can be called to re-raise the exception and continue the shutdown.

class Worker < Struct.new(:jobs_queue)
  def work
    job = jobs_queue.pop
    # work...
  rescue Shutdown => shutdown
    jobs_queue.push job if job.incomplete?
    shutdown.continue
  end
end

require 'graceful_shutdown'

WithGracefulShutdown do
  jobs = Queue.new
  Worker.new(jobs).start
end

As the blog posts continue, there will likely be some enhancements to this gem.

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Copyright 2014 Tim Uruski – Released under MIT License