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Diffstat (limited to 'lib/rubygems/vendor/timeout/lib/timeout.rb')
| -rw-r--r-- | lib/rubygems/vendor/timeout/lib/timeout.rb | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/lib/rubygems/vendor/timeout/lib/timeout.rb b/lib/rubygems/vendor/timeout/lib/timeout.rb new file mode 100644 index 0000000000..df97d64ca0 --- /dev/null +++ b/lib/rubygems/vendor/timeout/lib/timeout.rb @@ -0,0 +1,199 @@ +# frozen_string_literal: true +# Timeout long-running blocks +# +# == Synopsis +# +# require 'rubygems/vendor/timeout/lib/timeout' +# status = Gem::Timeout::timeout(5) { +# # Something that should be interrupted if it takes more than 5 seconds... +# } +# +# == Description +# +# Gem::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 Gem::Timeout.timeout instead. +# +# == Copyright +# +# Copyright:: (C) 2000 Network Applied Communication Laboratory, Inc. +# Copyright:: (C) 2000 Information-technology Promotion Agency, Japan + +module Gem::Timeout + VERSION = "0.4.1" + + # Internal error raised to when a timeout is triggered. + class ExitException < Exception + def exception(*) + self + end + end + + # Raised by Gem::Timeout.timeout when the block times out. + class Error < RuntimeError + def self.handle_timeout(message) + exc = ExitException.new(message) + + begin + yield exc + rescue ExitException => e + raise new(message) if exc.equal?(e) + raise + end + end + end + + # :stopdoc: + CONDVAR = ConditionVariable.new + QUEUE = Queue.new + QUEUE_MUTEX = Mutex.new + TIMEOUT_THREAD_MUTEX = Mutex.new + @timeout_thread = nil + private_constant :CONDVAR, :QUEUE, :QUEUE_MUTEX, :TIMEOUT_THREAD_MUTEX + + class Request + attr_reader :deadline + + def initialize(thread, timeout, exception_class, message) + @thread = thread + @deadline = GET_TIME.call(Process::CLOCK_MONOTONIC) + timeout + @exception_class = exception_class + @message = message + + @mutex = Mutex.new + @done = false # protected by @mutex + end + + def done? + @mutex.synchronize do + @done + end + end + + def expired?(now) + now >= @deadline + end + + def interrupt + @mutex.synchronize do + unless @done + @thread.raise @exception_class, @message + @done = true + end + end + end + + def finished + @mutex.synchronize do + @done = true + end + end + end + private_constant :Request + + def self.create_timeout_thread + watcher = Thread.new do + requests = [] + while true + until QUEUE.empty? and !requests.empty? # wait to have at least one request + req = QUEUE.pop + requests << req unless req.done? + end + closest_deadline = requests.min_by(&:deadline).deadline + + now = 0.0 + QUEUE_MUTEX.synchronize do + while (now = GET_TIME.call(Process::CLOCK_MONOTONIC)) < closest_deadline and QUEUE.empty? + CONDVAR.wait(QUEUE_MUTEX, closest_deadline - now) + end + end + + requests.each do |req| + req.interrupt if req.expired?(now) + end + requests.reject!(&:done?) + end + end + ThreadGroup::Default.add(watcher) unless watcher.group.enclosed? + watcher.name = "Gem::Timeout stdlib thread" + watcher.thread_variable_set(:"\0__detached_thread__", true) + watcher + end + private_class_method :create_timeout_thread + + def self.ensure_timeout_thread_created + unless @timeout_thread and @timeout_thread.alive? + TIMEOUT_THREAD_MUTEX.synchronize do + unless @timeout_thread and @timeout_thread.alive? + @timeout_thread = create_timeout_thread + end + end + end + end + + # We keep a private reference so that time mocking libraries won't break + # Gem::Timeout. + GET_TIME = Process.method(:clock_gettime) + private_constant :GET_TIME + + # :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, Gem::Timeout::Error + # +message+:: Error message to raise with Exception Class. + # Omitting will use the default, "execution expired" + # + # 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. However, the block can use + # ensure to prevent the handling of the exception. For that reason, this + # method cannot be relied on to enforce timeouts for untrusted blocks. + # + # If a scheduler is defined, it will be used to handle the timeout by invoking + # Scheduler#timeout_after. + # + # Note that this is both a method of module Gem::Timeout, so you can <tt>include + # Gem::Timeout</tt> into your classes so they have a #timeout method, as well as + # a module method, so you can call it directly as Gem::Timeout.timeout(). + def timeout(sec, klass = nil, message = nil, &block) #:yield: +sec+ + return yield(sec) if sec == nil or sec.zero? + + message ||= "execution expired" + + if Fiber.respond_to?(:current_scheduler) && (scheduler = Fiber.current_scheduler)&.respond_to?(:timeout_after) + return scheduler.timeout_after(sec, klass || Error, message, &block) + end + + Gem::Timeout.ensure_timeout_thread_created + perform = Proc.new do |exc| + request = Request.new(Thread.current, sec, exc, message) + QUEUE_MUTEX.synchronize do + QUEUE << request + CONDVAR.signal + end + begin + return yield(sec) + ensure + request.finished + end + end + + if klass + perform.call(klass) + else + Error.handle_timeout(message, &perform) + end + end + module_function :timeout +end |