In accordance with the sequence starting from the beginning CGI

Ruby CGI Doc:

The Common Gateway Interface ( CGI ) Is a simple protocol for passing an HTTP request from a web server to a standalone program, and returning the output to the web browser. Basically, a CGI program is called with the parameters of the request passed in either in the environment (GET) or via $ stdin (POST), and everything it prints to $ stdout is returned to the client.

This class focuses on process! Methods:

  1. def process! (provider = FCGI)
  2. mark_features!
  4. dispatcher_log: info, 'starting'
  5. process_each_request provider
  6. dispatcher_log: info, 'stopping gracefully'
  8. rescue Exception => error
  9. case error
  10. when SystemExit
  11. dispatcher_log: info, 'stopping after explicit exit'
  12. when SignalException
  13. dispatcher_error error, 'stopping after unhandled signal'
  14. else
  15. # Retry if exceptions occur more than 10 seconds apart.
  16. if Time.now - @ last_error_on> 10
  17. @ last_error_on = Time.now
  18. dispatcher_error error, 'retrying after unhandled exception'
  19. retry
  20. else
  21. dispatcher_error error, 'stopping after unhandled exception within 10 seconds of the last'
  22. end
  23. end
  24. end


(1) mark_features!

def mark_features!

@ features = $ ". clone

end



/ / Through the $ "to be all Rails loaded. Rb file name composed of list

(2) process_each_request

  1. def process_each_request (provider)
  2. cgi = nil
  4. catch: exit do
  5. provider.each_cgi do | cgi |
  6. process_request (cgi)
  8. case when_ready
  9. when: reload
  10. reload!
  11. when: restart
  12. close_connection (cgi)
  13. restart!
  14. when: exit
  15. close_connection (cgi)
  16. throw: exit
  17. end
  18. end
  19. end
  20. rescue SignalException => signal
  21. raise unless signal.message == 'SIGUSR1'
  22. close_connection (cgi)
  23. end


(3) process_request

  1. def process_request (cgi)
  2. @ processing, @ when_ready = true, nil
  3. gc_countdown
  5. with_signal_handler 'USR1' do
  6. begin
  7. Dispatcher.dispatch (cgi)
  8. rescue SignalException, SystemExit
  9. raise
  10. rescue Exception => error
  11. dispatcher_error error, 'unhandled dispatch error'
  12. end
  13. end
  14. ensure
  15. @ processing = false
  16. end


Next on the inside of the Dispatcher