Class: ChildManager

Inherits:
Object
  • Object
show all
Defined in:
lib/xing/managers/child.rb

Defined Under Namespace

Classes: ChildRecord

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ ChildManager

Returns a new instance of ChildManager.



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# File 'lib/xing/managers/child.rb', line 2

def initialize
  @child_pids = []
  @parent_pid = Process.pid
  @child_data = {}
end

Instance Attribute Details

#child_data ⇒ Object

Returns the value of attribute child_data.



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# File 'lib/xing/managers/child.rb', line 7

def child_data
  @child_data
end

#child_pids ⇒ Object

Returns the value of attribute child_pids.



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# File 'lib/xing/managers/child.rb', line 7

def child_pids
  @child_pids
end

Instance Method Details

#exited?(pid) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xing/managers/child.rb', line 27

def exited?(pid)
  return false unless child_data.has_key?(pid)
  return true unless child_data[pid].status.nil?

  begin
    _apid, status = *Process.wait2(pid, Process::WNOHANG | Process::WUNTRACED)
  rescue Errno::ECHILD
    return false
  end

  unless status.nil?
    child_data[pid].status = status
    return true
  end
  return false
end

#kill_all ⇒ Object 



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# File 'lib/xing/managers/child.rb', line 85

def kill_all
  unless Process.pid == @parent_pid
    puts "Although #{Process.pid} was asked to kill all, it isn't #@parent_pid the original parent"
    return
  end
  child_pids.each do |pid|
    kill_child(pid)
  end
  previous_term_trap = trap "TERM" do
    puts "Trapped TERM once"
    trap "TERM", previous_term_trap
  end
  Process::kill("TERM", 0)
end

#kill_child(pid) ⇒ Object 



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# File 'lib/xing/managers/child.rb', line 48

def kill_child(pid)
  unless Process.pid == @parent_pid
    puts "#{Process.pid} #@parent_pid Not original parent: not killing"
    return
  end
  puts "PID #{Process.pid} is killing child #{pid} #{child_data[pid].name}"

  if exited?(pid)
    puts "#{pid} #{child_data[pid].name} already exited"
    return
  end

  begin
    Process::kill("TERM", pid)
  rescue Errno::ESRCH
    puts "Hm. #{pid} is already gone: dead?"
    return
  end

  limit = 10
  start = Time.now
  while Time.now - start < limit
    begin
      Process::kill(0, pid)
      sleep(0.1)
    rescue Errno::ESRCH
      return
    end
  end

  begin
    Process::kill("KILL", pid)
  rescue Errno::ESRCH
    return
  end
end

#start_child(name, task) ⇒ Object 



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# File 'lib/xing/managers/child.rb', line 11

def start_child(name, task)
  child_pid = Process.fork do
    Signal.trap("HUP") do
      puts "Parent exited"
      exit
    end

    exec(*(%w{bundle exec rake} + [task]))
  end
  puts "#{@parent_pid}: #{name} running in pid #{child_pid}"

  at_exit { kill_child(child_pid) }
  child_data[child_pid] = ChildRecord.new(name, nil)
  child_pids << child_pid
end

#wait_all ⇒ Object 



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# File 'lib/xing/managers/child.rb', line 44

def wait_all
  Process.waitall
end