Module: Forker

Defined in:
lib/forker.rb

Defined Under Namespace

Modules: CLI

Class Method Summary collapse

Class Method Details

.fork!(opts = {}) ⇒ Object 



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# File 'lib/forker.rb', line 56

def self.fork!(opts={})
  opts = { :log => "/dev/null", :pid => "/var/run/#{File.basename($0)}.pid" }.merge(opts)

  $stdout.sync = $stderr.sync = true
  $stdin.reopen("/dev/null")

  exit if fork

  Process.setsid

  exit if fork

  Dir.chdir("/")   if opts[:chdir]
  File.umask(0000) if opts[:umask]

  if File.exist?(opts[:pid])
    begin
      existing_pid = File.read(opts[:pid]).to_i
      Process.kill(0, existing_pid) # See if proc exists
      abort "error: existing process #{existing_pid} using this pidfile, exiting"
    rescue Errno::ESRCH
      puts "warning: removing stale pidfile with pid #{existing_pid}"
    end
  end

  File.open(opts[:pid], 'w') { |f| f.write($$) }

  at_exit do
    ( File.read(opts[:pid]).to_i == $$ and File.unlink(opts[:pid]) ) rescue nil
  end

  puts "forked process is #{$$}"
  puts "output redirected to #{opts[:log]}"

  $stdout.reopen(opts[:log], 'a')
  $stderr.reopen(opts[:log], 'a')
  $stdout.sync = $stderr.sync = true
end

.kill(opts = {}) ⇒ Object 



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# File 'lib/forker.rb', line 95

def self.kill(opts={})
  begin
    pid = File.read(opts[:pid]).to_i
    sec = 60 # Seconds to wait before force killing
    Process.kill("TERM", pid)

    begin
      SystemTimer.timeout(sec) do
        loop do
          puts "waiting #{sec} seconds for #{pid} before sending KILL"
          Process.kill(0, pid) # See if proc exists

          sec -= 1
          sleep 1
        end
      end
    rescue Errno::ESRCH
      puts "killed process #{pid}"
    rescue Timeout::Error
      Process.kill("KILL", pid)
      puts "force killed process #{pid}"
    end

  rescue Errno::ENOENT
    puts "warning: pidfile #{opts[:pid]} does not exist"
  rescue Errno::ESRCH
    puts "warning: process #{pid} does not exist"
  end
end