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=-3.1 required=3.0 tests=AWL,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,SPF_PASS shortcircuit=no autolearn=no 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 A29071F87F for ; Thu, 22 Nov 2018 15:15:33 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 26566120E91; Fri, 23 Nov 2018 00:15:31 +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 6481C120E12 for ; Fri, 23 Nov 2018 00:15:29 +0900 (JST) Received: by filter0091p3mdw1.sendgrid.net with SMTP id filter0091p3mdw1-12607-5BF6C80E-4F 2018-11-22 15:15:26.679682258 +0000 UTC m=+588041.390551491 Received: from herokuapp.com (ec2-54-158-191-196.compute-1.amazonaws.com [54.158.191.196]) by ismtpd0023p1iad2.sendgrid.net (SG) with ESMTP id 8gO08ox2TICsMjPOtdj5dw Thu, 22 Nov 2018 15:15:26.630 +0000 (UTC) Date: Thu, 22 Nov 2018 15:15:26 +0000 (UTC) From: Greg.mpls@gmail.com To: ruby-core@ruby-lang.org Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 65375 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 14968 X-Redmine-Issue-Author: normalperson X-Redmine-Sender: MSP-Greg 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/Ymy4QrNMhiuLXJG8OTL2vJD1yS5cio3/6x8D6Gn3uQOpK6P0lEMKRYr+N0QoWf OzSI66g42oWyHRYD5UsYZ3Gek6cJn3W6v7Bg1ugGZq72+JlKrLBLBmiTvm+vCadtPV/Yl2az//kr35 vG8BVOS6ox5r9CMBTq3LV/5hu9w/1Ld1+5Gje308Wh3AsztpJNxwab0qEA== X-ML-Name: ruby-core X-Mail-Count: 89976 Subject: [ruby-core:89976] [Ruby trunk Bug#14968] [PATCH] io.c: make all pipes nonblocking by default 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 #14968 has been updated by MSP-Greg (Greg L). ruby-loco built r65909 green, and failed on r65922 and r65927. Using the r65927 build locally, test_drb.rb freezes on various tests intermittently: ``` DRbTests::TestDRbAry#test_07_break_18 DRbTests::TestDRbCore#test_07_private_missing DRbTests::TestDRbYield#test_01_one ``` I'm trying to narrow the issue, but no luck yet... Greg ---------------------------------------- Bug #14968: [PATCH] io.c: make all pipes nonblocking by default https://bugs.ruby-lang.org/issues/14968#change-75082 * Author: normalperson (Eric Wong) * Status: Closed * Priority: Normal * Assignee: * Target version: * ruby -v: * Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN ---------------------------------------- Crap, I always planned to have something like this for [Feature #13618] (auto-Fiber); but introducing a race condition for Timer-thread elimination in [Misc #14937] forced me to introduce this early. Anyways, I might have to revert and reintroduce timer-thread if this change is unnacceptable :< (I HATE timer thread) ``` io.c: make all pipes nonblocking by default All normal Ruby IO methods (IO#read, IO#gets, IO#write, ...) are all capable of appearing to be "blocking" when presented with a file description with the O_NONBLOCK flag set; so there is little risk of incompatibility within Ruby-using programs. The biggest compatibility risk is when spawning external programs. As a result, stdin, stdout, and stderr are now always made blocking before exec-family calls. Timer-thread elimination in https://bugs.ruby-lang.org/issues/14937 introduced a race condition in signal handling. It is possible to receive a signal inside BLOCKING_REGION right before read/write syscalls. If this patch cannot be accepted, I will have to revert to reintroduce timer-thread and increase resource use (which led to other failures in the past). The race condition introduced for [Misc #14937] led to rare CI failures on a few tests: - test/ruby/test_thread.rb (test_thread_timer_and_interrupt): http://www.rubyist.net/~akr/chkbuild/debian/ruby-trunk/log/20180805T080500Z.fail.html.gz - test/ruby/test_io.rb (test_race_gets_and_close): http://ci.rvm.jp/results/trunk@P895/1190369 This change is ALSO necessary to take advantage of (proposed lightweight concurrency (aka "auto-Fiber") or any similar proposal: https://bugs.ruby-lang.org/issues/13618 TODO: all sockets and FIFOs non-blocking by default, too ``` ---Files-------------------------------- 0001-io.c-make-all-pipes-nonblocking-by-default.patch (12.1 KB) -- https://bugs.ruby-lang.org/