Module: Timeout

Defined in:
lib/timeout.rb

Overview

timeout.rb

execution timeout

Synopsis

require 'timeout'
status = Timeout::timeout(5) {
  # Something that should be interrupted if it takes too much time...
}

Description

A way of performing a potentially long-running operation in a thread, and terminating it's execution if it hasn't finished by a fixed amount of time.

Previous versions of timeout didn't provide use a module for namespace. This version provides both Timeout.timeout, and a backwards-compatible #timeout.

Copyright

Copyright

(C) 2000 Network Applied Communication Laboratory, Inc.

Copyright

(C) 2000 Information-technology Promotion Agency, Japan

Defined Under Namespace

Classes: Error, ExitException

Constant Summary

THIS_FILE = 
/\A#{Regexp.quote(__FILE__)}:/o
CALLER_OFFSET = 
((c = caller[0]) && THIS_FILE =~ c) ? 1 : 0

Instance Method Summary (collapse)

Instance Method Details

- (Object) timeout(sec, klass = nil)

Executes the method's block. If the block execution terminates before sec seconds has passed, it returns the result value of the block. If not, it terminates the execution and raises exception (which defaults to Timeout::Error).

Note that this is both a method of module Timeout, so you can 'include Timeout' into your classes so they have a #timeout method, as well as a module method, so you can call it directly as Timeout.timeout().



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# File 'lib/timeout.rb', line 43

def timeout(sec, klass = nil)   #:yield: +sec+
  return yield(sec) if sec == nil or sec.zero?
  exception = klass || Class.new(ExitException)
  begin
    begin
      x = Thread.current
      y = Thread.start {
        begin
          sleep sec
        rescue => e
          x.raise e
        else
          x.raise exception, "execution expired"
        end
      }
      return yield(sec)
    ensure
      if y
        y.kill
        y.join # make sure y is dead.
      end
    end
  rescue exception => e
    rej = /\A#{Regexp.quote(__FILE__)}:#{__LINE__-4}\z/o
    (bt = e.backtrace).reject! {|m| rej =~ m}
    level = -caller(CALLER_OFFSET).size
    while THIS_FILE =~ bt[level]
      bt.delete_at(level)
      level += 1
    end
    raise if klass            # if exception class is specified, it
                              # would be expected outside.
    raise Error, e.message, e.backtrace
  end
end