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=-3.9 required=3.0 tests=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 2B99A1F4BD for ; Thu, 3 Oct 2019 15:32:36 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 17E83120A27; Fri, 4 Oct 2019 00:32:25 +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 B6D4F120A1E for ; Fri, 4 Oct 2019 00:32:21 +0900 (JST) Received: by filter0104p3las1.sendgrid.net with SMTP id filter0104p3las1-30146-5D961487-A9 2019-10-03 15:32:23.551891441 +0000 UTC m=+161048.046762880 Received: from herokuapp.com (unknown [54.161.249.108]) by ismtpd0039p1mdw1.sendgrid.net (SG) with ESMTP id ipZJlAbuRRSYlYpaq-6ZLA for ; Thu, 03 Oct 2019 15:32:23.390 +0000 (UTC) Date: Thu, 03 Oct 2019 15:32:23 +0000 (UTC) From: deivid.rodriguez@riseup.net Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 70786 X-Redmine-Project: ruby-trunk X-Redmine-Issue-Id: 15912 X-Redmine-Issue-Author: deivid X-Redmine-Issue-Assignee: ko1 X-Redmine-Sender: deivid 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?klzXTY0v3jOvaMSihdVenmzxCeXPrK4t1AV7GwiE8TgwjTSeZB2ELTxozwngph?= =?us-ascii?Q?s30=2Fdu0zblg=2FM+WREB8NZnHXzamUtq5SFwjFg1E?= =?us-ascii?Q?qdLbczk8u58ckLwLdshaJkDlzIPpuKAj7e5o01c?= =?us-ascii?Q?o6SWkOGuPy=2Fv5dUdq4wnNHumpqgIOgm6D=2FAC2GG?= =?us-ascii?Q?IMFW+rJYT5i9I9c7WYuevk3x3xj8hXYaZzw=3D=3D?= To: ruby-core@ruby-lang.org X-ML-Name: ruby-core X-Mail-Count: 95199 Subject: [ruby-core:95199] [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 deivid (David Rodr=EDguez). I tried my idea and, while it seemed [not hard to implement](https://github= .com/ruby/ruby/commit/ed0fd5d015860f5b2fa190d9287506d5b5142230), it's not g= oing to work, because many many more event would be generated and that brea= ks `byebug` and I'm guessing other TracePoint API consumers. It's also not = straightforward to communicate and understand, so I think your solution of = adding `TracepPoint#reopen` is better and more explicit. I can try to implement it but I'm not sure how it will go. ---------------------------------------- Feature #15912: Allow some reentrancy during TracePoint events https://bugs.ruby-lang.org/issues/15912#change-81875 * 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: