Class: Daemonizer::Worker

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, pm, worker_id, &blk) ⇒ Worker

Returns a new instance of Worker.

Raises:

  • (ArgumentError) 


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# File 'lib/daemonizer/worker.rb', line 7

def initialize(name, pm, worker_id, &blk)
  raise ArgumentError, "Need a worker block!" unless block_given?

  @name = name
  @pm = pm
  @worker_block = blk
  @worker_id = worker_id
  @process_name = "#{@name} worker: instance #{@worker_id}"
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/daemonizer/worker.rb', line 3

def name
  @name
end

#pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/daemonizer/worker.rb', line 5

def pid
  @pid
end

#process_name ⇒ Object (readonly)

Returns the value of attribute process_name.



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# File 'lib/daemonizer/worker.rb', line 4

def process_name
  @process_name
end

Instance Method Details

#run ⇒ Object 



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# File 'lib/daemonizer/worker.rb', line 21

def run
  return if shutdown?
  Daemonizer.logger.info "Forking..."
  @pid = Kernel.fork do
    Dir.chdir '/'
    File.umask 0000

    STDIN.reopen '/dev/null'
    STDOUT.reopen '/dev/null', 'a'
    STDERR.reopen STDOUT
    
    @pid = Process.pid
    Daemonizer.reopen_log_file
    Daemonizer.logger_context = "#{@pid}/#{@worker_id}"
    
    Daemonizer.logger.info "Log file reopened after fork"
    normal_exit = false
    begin
      $0 = "#{@process_name}\0"
      @worker_block.call(@worker_id)
      normal_exit = true
      exit(0)
    rescue Exception => e
      message = SystemExit === e ? "exit(#{e.status})" : e.to_s
      if SystemExit === e and e.success?
        if normal_exit
          Daemonizer.logger.info("Worker finished: normal return")
        else
          Daemonizer.logger.error("Worker exited: #{message} at #{e.backtrace.first}")
        end
      else
        Daemonizer.logger.error("Worker exited with error: #{message}\n  #{e.backtrace.join("\n  ")}")
      end
      Daemonizer.logger.debug("Terminating #{@name} worker: #{@pid}")
    end
  end
rescue Exception => e
  Daemonizer.logger.error("Exception from worker: #{e} at #{e.backtrace.first}")
end

#running?(verbose = false) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/daemonizer/worker.rb', line 61

def running?(verbose = false)
  return false unless @pid
  begin
    Process.waitpid(@pid, Process::WNOHANG)
    res = Process.kill(0, @pid)
    Daemonizer.logger.debug("KILL(#{@pid}) = #{res}") if verbose
    return true
  rescue Errno::ESRCH, Errno::ECHILD, Errno::EPERM => e
    Daemonizer.logger.error("Exception from kill: #{e} at #{e.backtrace.first}") if verbose
    return false
  end
end

#shutdown? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/daemonizer/worker.rb', line 17

def shutdown?
  @pm.shutdown?
end

#stop(force = false) ⇒ Object 



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# File 'lib/daemonizer/worker.rb', line 74

def stop(force = false)
  begin
    sig = force ? 'SIGKILL' : 'SIGTERM'
    Daemonizer.logger.debug("Sending #{sig} to ##{@pid}")
    Process.kill(sig, @pid)
  rescue Errno::ESRCH, Errno::ECHILD, Errno::EPERM=> e
    Daemonizer.logger.error("Exception from kill: #{e} at #{e.backtrace.first}")
  end
end