From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS4713 221.184.0.0/13 X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.1 Received: from neon.ruby-lang.org (neon.ruby-lang.org [221.186.184.75]) by dcvr.yhbt.net (Postfix) with ESMTP id C27F3208EB for ; Mon, 6 Aug 2018 04:46:12 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id BA336120A87; Mon, 6 Aug 2018 13:46:09 +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 E8660120A82 for ; Mon, 6 Aug 2018 13:46:06 +0900 (JST) Received: by filter0159p3mdw1.sendgrid.net with SMTP id filter0159p3mdw1-20355-5B67D28B-2 2018-08-06 04:46:03.02307374 +0000 UTC m=+551955.586808070 Received: from herokuapp.com (ec2-50-16-109-202.compute-1.amazonaws.com [50.16.109.202]) by ismtpd0010p1iad1.sendgrid.net (SG) with ESMTP id 5H3MGHMqQH-hWMbeTCEINw for ; Mon, 06 Aug 2018 04:46:02.996 +0000 (UTC) Date: Mon, 06 Aug 2018 04:46:03 +0000 (UTC) From: normalperson@yhbt.net To: ruby-core@ruby-lang.org Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 63680 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 14968 X-Redmine-Issue-Author: normalperson X-Redmine-Sender: normalperson 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/Ymy4QrNMhiuLXJG8OTL2vJD1yS4ULgYKL4ysdj57Yu2ajP8FFIVPSjM1lh6sBe 3PWbLMJXhmQDPg/O7Q1i0RK6OnM7/kmQO3DPaOCLFlJc3fy5FIXnqPlP2azt0XeM+4SXifXSHmQCgd klQJKS6XbUefWdnZBks/keyAD6imQK9/Mwt1xpr8wmRfR4RxsHohm3YXWQ== X-ML-Name: ruby-core X-Mail-Count: 88305 Subject: [ruby-core:88305] [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 reported by normalperson (Eric Wong). ---------------------------------------- Bug #14968: [PATCH] io.c: make all pipes nonblocking by default https://bugs.ruby-lang.org/issues/14968 * Author: normalperson (Eric Wong) * Status: Open * 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/