Module: Timeout

Defined in:
lib/timeout.rb

Overview

--

timeout.rb

execution timeout

Copyright

Copyright

(c) 2000 Network Applied Communication Laboratory, Inc.

Copyright

(c) 2000 Information-technology Promotion Agency, Japan

++

Description

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

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

Synopsis

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

Defined Under Namespace

Classes: Error, ExitException

Constant Summary collapse

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

Instance Method Summary collapse

Instance Method Details

#timeout(sec, klass = nil) ⇒ Object

Executes the method's block. If the block execution terminates before sec seconds has passed, it returns true. 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().

Raises:

  • (ThreadError) 


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# File 'lib/timeout.rb', line 52

def timeout(sec, klass = nil)
  return yield if sec == nil or sec.zero?
  raise ThreadError, "timeout within critical session" if Thread.critical
  exception = klass || Class.new(ExitException)
  begin
    x = Thread.current
    y = Thread.start {
      sleep sec
      x.raise exception, "execution expired" if x.alive?
    }
    yield sec
    #    return true
  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
  ensure
    y.kill if y and y.alive?
  end
end