From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS4713 221.184.0.0/13 X-Spam-Status: No, score=-4.0 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=3.4.2 Received: from neon.ruby-lang.org (neon.ruby-lang.org [221.186.184.75]) by dcvr.yhbt.net (Postfix) with ESMTP id 8AF941F609 for ; Wed, 28 Nov 2018 20:07:19 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id AACBA120DFC; Thu, 29 Nov 2018 05:07:17 +0900 (JST) Received: from o1678916x28.outbound-mail.sendgrid.net (o1678916x28.outbound-mail.sendgrid.net [167.89.16.28]) by neon.ruby-lang.org (Postfix) with ESMTPS id A0F17120CF0 for ; Thu, 29 Nov 2018 05:07:15 +0900 (JST) Received: by filter0101p3iad2.sendgrid.net with SMTP id filter0101p3iad2-18240-5BFEF570-2E 2018-11-28 20:07:12.517664545 +0000 UTC m=+1123561.411945315 Received: from herokuapp.com (ec2-54-166-118-97.compute-1.amazonaws.com [54.166.118.97]) by ismtpd0030p1iad1.sendgrid.net (SG) with ESMTP id 5ICjpZUgQ82G3HDkUvvWLg Wed, 28 Nov 2018 20:07:12.268 +0000 (UTC) Date: Wed, 28 Nov 2018 20:07:13 +0000 (UTC) From: samuel@oriontransfer.net To: ruby-core@ruby-lang.org Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 65533 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/Ymy4QrNMhiuLXJG8OTL2vJD1yS5MvseYNExdvmd2yuaTphVNNc8TEQ0AhGbt0X hc4/igA0CazZarZaU7vRIF9X+5p947aQ/SG32n8BSYlf7ARE/zbvi5ylNJp8KEnj75Iq/Sn1K9WDpI anrWyLFEyoc58zvjKzEcwlhqAipBvJlXbYkL3PgwmuvHRZzbVazGp3RVOg== X-ML-Name: ruby-core X-Mail-Count: 90136 Subject: [ruby-core:90136] [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). @k0kubun I like the general ideas presented here but the implementation is too heavy/specific for my use case. For example, it won't work on JRuby, TruffleRuby, or other implementations. That's the major benefit of using a gem for the reactor implementation. Additionally, I need to use Fiber for task switching. Does `Thread::Light` allow `yield`/`resume`? The tricky part about supporting a different backend is whether it changes semantics of operations. If it does, it's a big problem. If you try to use two different libraries of code that expect different backend semantics, it can cause many headache. That's why I think as an IO reactor, this is really great, but as a high level interface, I'm not convinced I can use it. I think we need to separate the model for concurrency from the backend selector/reactor implementation, and the front end should provide the appropriate hooks (i.e. `wait_readable`/`wait_writable`). @normalperson `libev` is okay, it's abstracted by nio4r which is battle tested. It's already proven that it can improve I/O concurrency of existing Ruby code base with no change to code provided you use an async aware application server e.g. falcon. ---------------------------------------- Feature #13618: [PATCH] auto fiber schedule for rb_wait_for_single_fd and rb_waitpid https://bugs.ruby-lang.org/issues/13618#change-75253 * 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/