class DeepTest::Warlock

Public Class Methods

new() click to toggle source
# File lib/deep_test/warlock.rb, line 3
def initialize
  @demons_semaphore = Mutex.new
  @demons = []
  @reapers = []
end

Public Instance Methods

any_running?() click to toggle source
# File lib/deep_test/warlock.rb, line 86
def any_running?
  @demons_semaphore.synchronize do
    @demons.any? {|name, pid| running?(pid)}
  end
end
demon_count() click to toggle source
# File lib/deep_test/warlock.rb, line 49
def demon_count
  @demons_semaphore.synchronize do
    @demons.size
  end
end
exit_when_none_running() click to toggle source
# File lib/deep_test/warlock.rb, line 76
def exit_when_none_running
  Thread.new do
    loop do
      Thread.pass
      exit(0) unless any_running?
      sleep(0.01)
    end
  end
end
running?(pid) click to toggle source

stolen from daemons

# File lib/deep_test/warlock.rb, line 93
def running?(pid)
  # Check if process is in existence
  # The simplest way to do this is to send signal '0'
  # (which is a single system call) that doesn't actually
  # send a signal
  begin
    Process.kill(0, pid)
    return true
  rescue Errno::ESRCH
    return false
  rescue ::Exception   # for example on EPERM (process exists but does not belong to us)
    return true
  #rescue Errno::EPERM
  #  return false
  end
end
start(name) { || ... } click to toggle source
# File lib/deep_test/warlock.rb, line 9
def start(name, &block)
  # Not synchronizing for the fork seems to cause
  # random errors (Bus Error, Segfault, and GC non-object)
  # in RemoteWorkerServer processes.
  #
  begin
    pid = nil
    @demons_semaphore.synchronize do 
      pid = DeepTest.drb_safe_fork do
        # Fork leaves the semaphore locked and we'll never make it
        # to end of synchronize block.
        #
        # The Ruby 1.8.6 C mutex implementation automatically treats
        # a mutex locked by a dead thread as unlocked and will raise
        # an error if we try to unlock it from this thread.
        #
        @demons_semaphore.unlock if @demons_semaphore.locked?

        begin
          yield
        rescue Exception => e
          DeepTest.logger.debug "Exception in #{name} (#{Process.pid}): #{e.message}"
          raise
        end

        exit
      end

      raise "fatal: fork returned nil" if pid.nil?
      add_demon name, pid
    end

    launch_reaper_thread name, pid

  rescue => e
    puts "exception starting #{name}: #{e}"
    puts "\t" + e.backtrace.join("\n\t")
  end
end
stop_all() click to toggle source
# File lib/deep_test/warlock.rb, line 55
def stop_all
  DeepTest.logger.debug("stopping all demons")
  receivers = @demons_semaphore.synchronize do
    @demons.reverse
  end

  receivers.reverse.each do |demon|
    name, pid = demon
    if running?(pid)
      DeepTest.logger.debug("Sending SIGTERM to #{name}, #{pid}")
      Process.kill("TERM", pid)
    end
  end
  DeepTest.logger.debug("Warlock: Stopped all receivers")

  DeepTest.logger.debug("waiting for reapers")
  @reapers.each {|r| r.join}

  DeepTest.logger.debug("Warlock: done reaping processes")
end

Protected Instance Methods

add_demon(name, pid) click to toggle source
# File lib/deep_test/warlock.rb, line 112
def add_demon(name, pid)
  DeepTest.logger.debug "Started: #{name} (#{pid})"
  @demons << [name, pid]
end
launch_reaper_thread(name, pid) click to toggle source
# File lib/deep_test/warlock.rb, line 123
def launch_reaper_thread(name, pid)
  @reapers << Thread.new do
    Process.detach(pid).join
    DeepTest.logger.debug("#{name} (#{pid}) reaped")
    @demons_semaphore.synchronize do
      DeepTest.logger.debug("Warlock Reaper: removing #{name} (#{pid}) from demon list")
      remove_demon name, pid
    end
  end
end
remove_demon(name, pid) click to toggle source
# File lib/deep_test/warlock.rb, line 117
def remove_demon(name, pid)
  @demons.delete [name, pid]
  DeepTest.logger.debug "Stopped: #{name} (#{pid})"
end