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Diffstat (limited to 'trunk/lib/timeout.rb')
-rw-r--r-- | trunk/lib/timeout.rb | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/trunk/lib/timeout.rb b/trunk/lib/timeout.rb new file mode 100644 index 0000000000..19ccb96d3e --- /dev/null +++ b/trunk/lib/timeout.rb @@ -0,0 +1,108 @@ +# = 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 + +module Timeout + # Raised by Timeout#timeout when the block times out. + class Error < RuntimeError + end + class ExitException < ::Exception # :nodoc: + end + + THIS_FILE = /\A#{Regexp.quote(__FILE__)}:/o + CALLER_OFFSET = ((c = caller[0]) && THIS_FILE =~ c) ? 1 : 0 + + # 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(). + def timeout(sec, klass = nil) #:yield: +sec+ + return yield(sec) if sec == nil or sec.zero? + exception = klass || Class.new(ExitException) + begin + x = Thread.current + y = Thread.start { + sleep sec + x.raise exception, "execution expired" if x.alive? + } + return yield(sec) + 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 + if y and y.alive? + y.kill + y.join # make sure y is dead. + end + end + end + + module_function :timeout +end + +# Identical to: +# +# Timeout::timeout(n, e, &block). +# +# Defined for backwards compatibility with earlier versions of timeout.rb, see +# Timeout#timeout. +def timeout(n, e = nil, &block) + Timeout::timeout(n, e, &block) +end + +# Another name for Timeout::Error, defined for backwards compatibility with +# earlier versions of timeout.rb. +TimeoutError = Timeout::Error + +if __FILE__ == $0 + p timeout(5) { + 45 + } + p timeout(5, TimeoutError) { + 45 + } + p timeout(nil) { + 54 + } + p timeout(0) { + 54 + } + p timeout(5) { + loop { + p 10 + sleep 1 + } + } +end |