From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS4713 221.184.0.0/13 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from neon.ruby-lang.org (neon.ruby-lang.org [221.186.184.75]) by dcvr.yhbt.net (Postfix) with ESMTP id A20ED2023D for ; Mon, 7 May 2018 11:39:47 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id B605112095D; Mon, 7 May 2018 20:39:43 +0900 (JST) Received: from o1678948x4.outbound-mail.sendgrid.net (o1678948x4.outbound-mail.sendgrid.net [167.89.48.4]) by neon.ruby-lang.org (Postfix) with ESMTPS id 8E361120959 for ; Mon, 7 May 2018 20:39:40 +0900 (JST) Received: by filter0026p3iad2.sendgrid.net with SMTP id filter0026p3iad2-22536-5AF03AF7-66 2018-05-07 11:39:35.683409378 +0000 UTC Received: from herokuapp.com (ec2-54-196-176-104.compute-1.amazonaws.com [54.196.176.104]) by ismtpd0002p1iad1.sendgrid.net (SG) with ESMTP id tpPjMUiaSbSmKrPYmLaeQw Mon, 07 May 2018 11:39:35.596 +0000 (UTC) Date: Mon, 07 May 2018 11:39:36 +0000 (UTC) From: samuel@oriontransfer.net To: ruby-core@ruby-lang.org Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 62286 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 13618 X-Redmine-Issue-Author: normalperson X-Redmine-Issue-Assignee: normalperson X-Redmine-Sender: ioquatix X-Mailer: Redmine X-Redmine-Host: bugs.ruby-lang.org X-Redmine-Site: Ruby Issue Tracking System X-Auto-Response-Suppress: All Auto-Submitted: auto-generated X-SG-EID: ync6xU2WACa70kv/Ymy4QrNMhiuLXJG8OTL2vJD1yS6g9chHduFfyeARmG7VDivZxAPt3pf9VHyOaH vAgAhaEeB/rF6+zTXNhvNZ9npTSEJeencQGtbKfH2Qd+UBkpL5dX9JIEHURaCS8FRnjmA6RNshfgyg WLCzC9bsFv3yC50M3pqaGDIr+4mppy7iw0EUNF1imTJR3jjfFKY4Q6AxBQ== X-ML-Name: ruby-core X-Mail-Count: 86929 Subject: [ruby-core:86929] [Ruby trunk Feature#13618] [PATCH] auto fiber schedule for rb_wait_for_single_fd and rb_waitpid X-BeenThere: ruby-core@ruby-lang.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: Ruby developers List-Id: Ruby developers List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ruby-core-bounces@ruby-lang.org Sender: "ruby-core" Issue #13618 has been updated by ioquatix (Samuel Williams). > Can you please summarize and perhaps link to code they talk about? The simplest summary I can give is that OS schedulers don't know what threads to wake up for optimal IO latency. So, Google implemented an API for cooperatively scheduling user threads within the OS time slice. They could have, say, a thread receiving events from the kernel via epoll, and then "yield" to the thread that was waiting for that event without requiring the OS to schedule it. > Again, Mio (Glasgow Haskell Compiler) is most similar to what > I'm working on, here, and that scales to some ridiculous number > of cores Thanks for that I will read it. I will assume you've implemented something similar, but I have a question, when processing events, when handling events that don't belong to the current thread, you put them in a queue. How does the other thread know to wake up? ---------------------------------------- Feature #13618: [PATCH] auto fiber schedule for rb_wait_for_single_fd and rb_waitpid https://bugs.ruby-lang.org/issues/13618#change-71895 * Author: normalperson (Eric Wong) * Status: Assigned * Priority: Normal * Assignee: normalperson (Eric Wong) * Target version: ---------------------------------------- ``` auto fiber schedule for rb_wait_for_single_fd and rb_waitpid Implement automatic Fiber yield and resume when running rb_wait_for_single_fd and rb_waitpid. The Ruby API changes for Fiber are named after existing Thread methods. main Ruby API: Fiber#start -> enable auto-scheduling and run Fiber until it automatically yields (due to EAGAIN/EWOULDBLOCK) The following behave like their Thread counterparts: Fiber.start - Fiber.new + Fiber#start (prelude.rb) Fiber#join - run internal scheduler until Fiber is terminated Fiber#value - ditto Fiber#run - like Fiber#start (prelude.rb) Right now, it takes over rb_wait_for_single_fd() and rb_waitpid() function if the running Fiber is auto-enabled (cont.c::rb_fiber_auto_sched_p) Changes to existing functions are minimal. New files (all new structs and relations should be documented): iom.h - internal API for the rest of RubyVM (incomplete?) iom_internal.h - internal header for iom_(select|epoll|kqueue).h iom_epoll.h - epoll-specific pieces iom_kqueue.h - kqueue-specific pieces iom_select.h - select-specific pieces iom_pingable_common.h - common code for iom_(epoll|kqueue).h iom_common.h - common footer for iom_(select|epoll|kqueue).h Changes to existing data structures: rb_thread_t.afrunq - list of fibers to auto-resume rb_vm_t.iom - Ruby I/O Manager (rb_iom_t) :) Besides rb_iom_t, all the new structs are stack-only and relies extensively on ccan/list for branch-less, O(1) insert/delete. As usual, understanding the data structures first should help you understand the code. Right now, I reuse some static functions in thread.c, so thread.c includes iom_(select|epoll|kqueue).h TODO: Hijack other blocking functions (IO.select, ...) I am using "double" for timeout since it is more convenient for arithmetic like parts of thread.c. Most platforms have good FP, I think. Also, all "blocking" functions (rb_iom_wait*) will have timeout support. ./configure gains a new --with-iom=(select|epoll|kqueue) switch libkqueue: libkqueue support is incomplete; corner cases are not handled well: 1) multiple fibers waiting on the same FD 2) waiting for both read and write events on the same FD Bugfixes to libkqueue may be necessary to support all corner cases. Supporting these corner cases for native kqueue was challenging, even. See comments on iom_kqueue.h and iom_epoll.h for nuances. Limitations Test script I used to download a file from my server: ----8<--- require 'net/http' require 'uri' require 'digest/sha1' require 'fiber' url = 'http://80x24.org/git-i-forgot-to-pack/objects/pack/pack-97b25a76c03b489d4cbbd85b12d0e1ad28717e55.idx' uri = URI(url) use_ssl = "https" == uri.scheme fibs = 10.times.map do Fiber.start do cur = Fiber.current.object_id # XXX getaddrinfo() and connect() are blocking # XXX resolv/replace + connect_nonblock Net::HTTP.start(uri.host, uri.port, use_ssl: use_ssl) do |http| req = Net::HTTP::Get.new(uri) http.request(req) do |res| dig = Digest::SHA1.new res.read_body do |buf| dig.update(buf) #warn "#{cur} #{buf.bytesize}\n" end warn "#{cur} #{dig.hexdigest}\n" end end warn "done\n" :done end end warn "joining #{Time.now}\n" fibs[-1].join(4) warn "joined #{Time.now}\n" all = fibs.dup warn "1 joined, wait for the rest\n" until fibs.empty? fibs.each(&:join) fibs.keep_if(&:alive?) warn fibs.inspect end p all.map(&:value) Fiber.new do puts 'HI' end.run.join ``` ---Files-------------------------------- 0001-auto-fiber-schedule-for-rb_wait_for_single_fd-and-rb.patch (82.8 KB) -- https://bugs.ruby-lang.org/