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_HELO_NONE,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 72D631F45A for ; Tue, 13 Aug 2019 08:15:04 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 7B351120A80; Tue, 13 Aug 2019 17:14:55 +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 E6615120A66 for ; Tue, 13 Aug 2019 17:14:52 +0900 (JST) Received: by filter0073p3iad2.sendgrid.net with SMTP id filter0073p3iad2-24183-5D52717E-27 2019-08-13 08:14:54.707296149 +0000 UTC m=+1516274.251646538 Received: from herokuapp.com (unknown [3.81.120.68]) by ismtpd0045p1mdw1.sendgrid.net (SG) with ESMTP id IcESMdaYQCiTF3P02vxj_Q for ; Tue, 13 Aug 2019 08:14:54.539 +0000 (UTC) Date: Tue, 13 Aug 2019 08:14:54 +0000 (UTC) From: ko1@atdot.net Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 69865 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 15912 X-Redmine-Issue-Author: deivid X-Redmine-Issue-Assignee: ko1 X-Redmine-Sender: ko1 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: =?us-ascii?Q?fVTMYOBjtdvXNcWwrscBhLsHItUXVK5L4mtnq0mdcRcsoQZQMxFhTAoVF=2FSbqt?= =?us-ascii?Q?IAibkEnQ1HqnkhK2F33fTd5K1RUoMIavirRz6J6?= =?us-ascii?Q?YKwjnBdGdETK2bvsli7HODG7MTUHufiAyAbaGXi?= =?us-ascii?Q?FxwB+dKFWz=2FyKgZaUX62U6qIM9kJMpSfWF+xXvQ?= =?us-ascii?Q?aB+7vxE49vw7n?= To: ruby-core@ruby-lang.org X-ML-Name: ruby-core X-Mail-Count: 94318 Subject: [ruby-core:94318] [Ruby master Feature#15912] Allow some reentrancy during TracePoint events 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="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: ruby-core-bounces@ruby-lang.org Sender: "ruby-core" Issue #15912 has been updated by ko1 (Koichi Sasada). Your proposal is, prohibit "same" tracepoint object, right? I misreading th= at your suggestion is to prohibit same event (when line event handler is wo= rking, other line event handler can't be fired, but :class event handler ca= n fire). ---- If my understanding is correctly, while running `line_handler2`, `line_hand= ler1` is invoked. right? ``` * main * :line event * line_handler1 * :line event * line_handler2 * :line event * line_handler2 * line_handler2 * :line event * line_handler1 * :line event * line_handler1 * finish all line hooks * continue main ``` ---------------------------------------- Feature #15912: Allow some reentrancy during TracePoint events https://bugs.ruby-lang.org/issues/15912#change-80705 * Author: deivid (David Rodr=EDguez) * Status: Assigned * Priority: Normal * Assignee: ko1 (Koichi Sasada) * Target version: = ---------------------------------------- I got a report in byebug about byebug being incompatible with zeitwerk. Thi= s one: https://github.com/deivid-rodriguez/byebug/issues/564. This is a pro= blem because zeitwerk is the default Rails code loader, and byebug is the d= efault Rails debugger. Both of these tools rely on the TracePoint API: * Byebug uses a bunch of TracePoint events to stop execution at certain poi= nts in your program. * Zeitwek uses `:class` events to be able to resolve some circular edge cas= es. I investigated the problem and I think the issue is that while stopped at t= he byebug prompt, we're actually in the middle of processing a TracePoint e= vent. That means that further TracePoint events triggered at the byebug's p= rompt will be ignored, because otherwise we could get into an infinite loop= where the handling of events would trigger more events that trigger themse= lves the execution of handlers again. I understand why the TracePoint API does this, but if we could allow some l= evel of reentrancy here, we could probably make these tools play nice toget= her. I figure if we kept a stack of TracePoint event handlers being run, an= d check that the current event type is not already in the stack, we would a= llow :class events to be triggered from :line events, and I think that woul= d allow Zeitwerk to work within byebug. What do you think about this, @ko1? -- = https://bugs.ruby-lang.org/ Unsubscribe: