Class: RailsFCGIHandler

Inherits:
Object show all
Defined in:
lib/fcgi_handler.rb

Constant Summary collapse

SIGNALS = 
{
  'HUP'  => :reload,
  'TERM' => :graceful_exit,
  'USR1' => :graceful_exit
}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(log_file_path = nil, gc_request_period = nil) {|_self| ... } ⇒ RailsFCGIHandler

Initialize the FastCGI instance with the path to a crash log detailing unhandled exceptions (default RAILS_ROOT/log/fastcgi.crash.log) and the number of requests to process between garbage collection runs (default nil for normal GC behavior.) Optionally, pass a block which takes this instance as an argument for further configuration.

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/fcgi_handler.rb', line 28

def initialize(log_file_path = nil, gc_request_period = nil)
  @when_ready = nil

  self.log_file_path = log_file_path || "#{RAILS_ROOT}/log/fastcgi.crash.log"
  self.gc_request_period = gc_request_period

  # Yield for additional configuration.
  yield self if block_given?

  # Safely install signal handlers.
  install_signal_handlers

  # Start error timestamp at 11 seconds ago.
  @last_error_on = Time.now - 11

  dispatcher_log(:info, "starting")
end

Instance Attribute Details

#gc_request_period ⇒ Object

Returns the value of attribute gc_request_period.



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# File 'lib/fcgi_handler.rb', line 15

def gc_request_period
  @gc_request_period
end

#log_file_path ⇒ Object

Returns the value of attribute log_file_path.



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# File 'lib/fcgi_handler.rb', line 14

def log_file_path
  @log_file_path
end

#when_ready ⇒ Object (readonly)

Returns the value of attribute when_ready.



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# File 'lib/fcgi_handler.rb', line 12

def when_ready
  @when_ready
end

Class Method Details

.process!(*args, &block) ⇒ Object

Initialize and run the FastCGI instance, passing arguments through to new.



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

def self.process!(*args, &block)
  new(*args, &block).process!
end

Instance Method Details

#process!(provider = FCGI) ⇒ Object 



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# File 'lib/fcgi_handler.rb', line 46

def process!(provider = FCGI)
  # Make a note of $" so we can safely reload this instance.
  mark!

  # Begin countdown to garbage collection.
  run_gc! if gc_request_period

  provider.each_cgi do |cgi| 
    # Safely reload this instance if requested.
    if when_ready == :reload
      run_gc! if gc_request_period
      restore!
      @when_ready = nil
      dispatcher_log(:info, "reloaded")
    end

    process_request(cgi)

    # Break if graceful exit requested.
    break if when_ready == :exit

    # Garbage collection countdown.
    if gc_request_period
      @gc_request_countdown -= 1
      run_gc! if @gc_request_countdown <= 0
    end
  end

  GC.enable
  dispatcher_log(:info, "terminated gracefully")

rescue SystemExit => exit_error
  dispatcher_log(:info, "terminated by explicit exit")

rescue Object => fcgi_error
  # retry on errors that would otherwise have terminated the FCGI process,
  # but only if they occur more than 10 seconds apart.
  if !(SignalException === fcgi_error) && Time.now - @last_error_on > 10
    @last_error_on = Time.now
    dispatcher_error(fcgi_error, "almost killed by this error")
    retry
  else
    dispatcher_error(fcgi_error, "killed by this error")
  end
end