Class: Clicker::LaunchLock

Inherits:
Object
  • Object
show all
Defined in:
lib/clicker/launch_lock.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(program_name) ⇒ LaunchLock

Returns a new instance of LaunchLock.



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# File 'lib/clicker/launch_lock.rb', line 8

def initialize(program_name)
  @config_dir = "#{ENV['HOME']}/.config/#{program_name}"
  @lock_file_path = "#{@config_dir}/#{program_name}.lock"
  FileUtils.mkdir_p(@config_dir)
end

Instance Attribute Details

#lock_file_path ⇒ Object (readonly)

Returns the value of attribute lock_file_path.



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# File 'lib/clicker/launch_lock.rb', line 6

def lock_file_path
  @lock_file_path
end

Instance Method Details

#locked? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/clicker/launch_lock.rb', line 29

def locked?
  File.open(@lock_file_path, 'r') do |f|
    rv =  f.flock(File::LOCK_EX | File::LOCK_NB)
    case rv
    when 0
	return false
    when false
	return true
    end
  end
rescue Errno::ENOENT
  return false
end

#owner ⇒ Object 



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# File 'lib/clicker/launch_lock.rb', line 43

def owner
  File.open(@lock_file_path) do |f|
    success = f.flock(File::LOCK_EX | File::LOCK_NB)
    if success
      return nil # owner is not alive...
    else
      pid = f.gets.to_i
      return pid
    end
  end
rescue Errno::ENOENT
  return nil
end

#try_lock ⇒ Object 



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# File 'lib/clicker/launch_lock.rb', line 14

def try_lock
  File.open(@lock_file_path, 'r+') do |f|
    success = f.flock(File::LOCK_EX | File::LOCK_NB)
    if success
      f.puts Process.pid
      f.flush
	f.truncate(f.pos)
      yield
      return true
    else
      return false
    end
  end
end