Class: Pitchfork::Flock

Inherits:
Object
  • Object
show all
Defined in:
lib/pitchfork/flock.rb

Constant Summary collapse

Error = 
Class.new(StandardError)

Instance Method Summary collapse

Constructor Details

#initialize(name) ⇒ Flock

Returns a new instance of Flock.



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# File 'lib/pitchfork/flock.rb', line 7

def initialize(name)
  @name = name
  @file = Tempfile.create([name, '.lock'])
  @file.write("#{Process.pid}\n")
  @file.flush
  @owned = false
end

Instance Method Details

#at_fork ⇒ Object 



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# File 'lib/pitchfork/flock.rb', line 15

def at_fork
  @owned = false
  @file.close
  @file = File.open(@file.path, "w")
  nil
end

#to_io ⇒ Object 



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# File 'lib/pitchfork/flock.rb', line 22

def to_io
  @file
end

#try_lock ⇒ Object

Raises:



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# File 'lib/pitchfork/flock.rb', line 32

def try_lock
  raise Error, "Pitchfork::Flock(#{@name}) trying to lock an already owned lock" if @owned

  if @file.flock(File::LOCK_EX | File::LOCK_NB)
    @owned = true
  else
    false
  end
end

#unlink ⇒ Object 



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# File 'lib/pitchfork/flock.rb', line 26

def unlink
  File.unlink(@file.path)
rescue Errno::ENOENT
  false
end

#unlock ⇒ Object

Raises:



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# File 'lib/pitchfork/flock.rb', line 42

def unlock
  raise Error, "Pitchfork::Flock(#{@name}) trying to unlock a non-owned lock" unless @owned

  begin
    if @file.flock(File::LOCK_UN)
      @owned = false
      true
    else
      false
    end
  end
end