Class: RobustServer

Inherits:
Object
  • Object
show all
Defined in:
lib/robustserver.rb

Overview

Easy problem-handler for your Server.

A Server should never crash. If an Exception raised, which is not rescued, your program will shutdown abnormaly. Or if a signal tries to “kill” your program, your program will shutdown abnormaly too.

With RobustServer these errors will be a more unimportant problem and It’ll be easier to handle.

Subclasses should implements #run, which will be your main-worker. For initializing, you can override #initialize, but doen’t forget to call super.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*p) ⇒ RobustServer

Returns a new instance of RobustServer.



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# File 'lib/robustserver.rb', line 113

def initialize *p
	sh = method :signal_handler
	@sigs = {
		Signal[:INT] => sh, Signal[:HUP] => nil, Signal[:TERM] => sh,
		Signal[:KILL] => sh, Signal[:USR1] => nil, Signal[:USR2] => nil
	}
	@signals = []
end

Instance Attribute Details

#signals ⇒ Object (readonly)

Returns the value of attribute signals.



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# File 'lib/robustserver.rb', line 107

def signals
  @signals
end

Class Method Details

.main(*argv) ⇒ Object 



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# File 'lib/robustserver.rb', line 109

def self.main *argv
	self.new( *argv).main
end

Instance Method Details

#at_exit ⇒ Object 



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# File 'lib/robustserver.rb', line 151

def at_exit
end

#main(max = nil, range = nil) ⇒ Object 



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# File 'lib/robustserver.rb', line 132

def main max = nil, range = nil
	retries = Retries.new max, range
	trapping
	$stderr.puts "Arbeit wird nun aufgenommen..."
	begin
		self.run
	rescue SystemExit, Interrupt, SignalException
		$stderr.puts "Das Beenden des Programms wurde angefordert. #{$!}"
	rescue Object
		$stderr.puts [:rescue, $!, $!.class, $!.backtrace].inspect
		retry  if retries.retry?
		$stderr.print "Zuviele Fehler in zu kurzer Zeit.  Ich gebe auf und "
	end
	$stderr.puts "Unbeachtete Signale: #{@signals.map(&Signal.method(:[])).join( ', ')}"
	trapping
	self.at_exit
	$stderr.puts "Beende mich selbst."
end

#signal_handler(s) ⇒ Object 



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# File 'lib/robustserver.rb', line 126

def signal_handler s
	$stderr.puts [:signal, s, Signal[s]].inspect
	s = s
	@signals.push s  unless @signals.include? s
end

#trapping ⇒ Object 



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# File 'lib/robustserver.rb', line 122

def trapping
	@sigs.each { |s, p|  @sigs[s] = trap s, p  }  if @sigs
end