#--
# = 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...
# }
#
module Timeout
##
# Raised by Timeout#timeout when the block times out.
class Error < Interrupt
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 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().
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 {
begin
sleep sec
rescue => e
x.raise e
else
x.raise exception, "execution expired" if x.alive?
end
}
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
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) # :nodoc:
Timeout::timeout(n, e, &block)
end
##
# Another name for Timeout::Error, defined for backwards compatibility with
# earlier versions of timeout.rb.
TimeoutError = Timeout::Error # :nodoc:
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
|