Class: PidFileBlock

Inherits:
Object
  • Object
show all
Defined in:
lib/pid_file_block.rb,
lib/pid_file_block/version.rb,
lib/pid_file_block/application.rb,
lib/pid_file_block/process_exists_error.rb

Defined Under Namespace

Modules: Version Classes: Application, ProcessExistsError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(piddir: '/run', pidfile:) ⇒ PidFileBlock

Returns a new instance of PidFileBlock.



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# File 'lib/pid_file_block.rb', line 8

def initialize(piddir: '/run', pidfile:)
  pidfile ||= File.basename($0, '.*')
  @pid_file_full_name = File.join(piddir, pidfile)
end

Instance Attribute Details

#pid_file_full_name ⇒ Object (readonly)

Returns the value of attribute pid_file_full_name.



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# File 'lib/pid_file_block.rb', line 6

def pid_file_full_name
  @pid_file_full_name
end

Instance Method Details

#kill(signal: "TERM") ⇒ Object 



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# File 'lib/pid_file_block.rb', line 64

def kill(signal: "TERM")
    pid = nil
    File.open(@pid_file_full_name, 'r') do |f|
      f.flock(File::LOCK_SH)
      pid_str = f.read
      begin
        pid = Integer(pid_str)
      rescue ArgumentError
        return false
      end    
    end
    Process.kill(signal, pid)
    return pid
end

#open ⇒ Object 



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# File 'lib/pid_file_block.rb', line 13

def open
  loop do
    begin
      File.open(@pid_file_full_name, 'r') do |f|
        f.flock(File::LOCK_EX)
        if process_running?(f)
          # f.flock(File::LOCK_UN)
          raise PidFileBlock::ProcessExistsError
        end
        unlink_pid_file_if_exists
      end
    rescue Errno::ENOENT
    end
    begin
      File.open(@pid_file_full_name,
                File::Constants::RDWR|File::Constants::CREAT|File::Constants::EXCL) do |f|
        f.flock(File::LOCK_EX)
        if process_running?(f)
          f.flock(File::LOCK_UN)
          raise PidFileBlock::ProcessExistsError
        end
        write_pid(f)
        f.flock(File::LOCK_UN)
      end
      break
    rescue Errno::EEXIST
    end
  end
  yield
  unlink_pid_file_if_exists
end

#release ⇒ Object 



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# File 'lib/pid_file_block.rb', line 45

def release
  our_pid = $$
  File.open(@pid_file_full_name, 'r') do |f|
    f.flock(File::LOCK_SH)
    file_pid_str = f.read
    begin
      file_pid = Integer(file_pid_str)
    rescue ArgumentError
      return false
    end      
    if file_pid == our_pid
      unlink_pid_file_if_exists
      return true
    else
      return false
    end
  end
end