# 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
end
class ExitException < ::Exception # :nodoc:
end
# :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+.
#
# 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?
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
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
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