# Timeout long-running blocks
#
# == Synopsis
#
# require 'timeout'
# status = Timeout::timeout(5) {
# # Something that should be interrupted if it takes more than 5 seconds...
# }
#
# == Description
#
# Timeout provides a way to auto-terminate a potentially long-running
# operation if it hasn't finished in a fixed amount of time.
#
# Previous versions didn't use a module for namespacing, however
# #timeout is provided for backwards compatibility. You
# should prefer Timeout#timeout instead.
#
# == 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
attr_reader :thread
def self.catch(*args)
exc = new(*args)
exc.instance_variable_set(:@thread, Thread.current)
exc.freeze
::Kernel.catch(exc) {yield exc}
end
def exception(*)
if self.thread == Thread.current
bt = caller
begin
throw(self, bt)
rescue ArgumentError => e
raise unless e.message.start_with?("uncaught throw")
raise Error, message, backtrace
end
end
self
end
end
ExitException = Error
# :stopdoc:
THIS_FILE = /\A#{Regexp.quote(__FILE__)}:/o
CALLER_OFFSET = ((c = caller[0]) && THIS_FILE =~ c) ? 1 : 0
# :startdoc:
# Perform an operation in a block, raising an error if it takes longer than
# +sec+ seconds to complete.
#
# +sec+:: Number of seconds to wait for the block to terminate. Any number
# may be used, including Floats to specify fractional seconds. A
# value of 0 or +nil+ will execute the block without any timeout.
# +klass+:: Exception Class to raise if the block fails to terminate
# in +sec+ seconds. Omitting will use the default, Timeout::Error
#
# Returns the result of the block *if* the block completed before
# +sec+ seconds, otherwise throws an exception, based on the value of +klass+.
#
# The exception thrown to terminate the given block cannot be rescued inside
# the block unless +klass+ is given explicitly.
#
# Note that this is both a method of module Timeout, so you can <tt>include
# Timeout</tt> 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?
message = "execution expired"
e = Error
bl = proc do |exception|
begin
x = Thread.current
y = Thread.start {
begin
sleep sec
rescue => e
x.raise e
else
x.raise exception, message
end
}
return yield(sec)
ensure
if y
y.kill
y.join # make sure y is dead.
end
end
end
if klass
begin
bl.call(klass)
rescue klass => e
bt = e.backtrace
end
else
bt = Error.catch(message, &bl)
end
rej = /\A#{Regexp.quote(__FILE__)}:#{__LINE__-4}\z/o
bt.reject! {|m| rej =~ m}
level = -caller(CALLER_OFFSET).size
while THIS_FILE =~ bt[level]
bt.delete_at(level)
end
raise(e, message, bt)
end
module_function :timeout
end
# Identical to:
#
# Timeout::timeout(n, e, &block).
#
# This method is deprecated and provided only for backwards compatibility.
# You should use Timeout#timeout instead.
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