From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from omta36.uswest2.a.cloudfilter.net (omta36.uswest2.a.cloudfilter.net [35.89.44.35]) by sourceware.org (Postfix) with ESMTPS id 4B0AC3858037 for ; Fri, 12 Jan 2024 18:22:21 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 4B0AC3858037 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=tromey.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tromey.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 4B0AC3858037 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=35.89.44.35 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1705083748; cv=none; b=TR2K7yxY51isTmgyJvmLcXex7d5aZeUxJ6T6ABPKyd96oNLFgtOSOxU9jQChJT5lpfB5DhYqcjLitnthjpfbG/bbmb/Ea9wghyyFTaeLpe55ihMBSYAnjsiW1oI/fl6eYP0AD1832dfRIvy0eFCOzqlZDHw6cHKmOnmToko071I= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1705083748; c=relaxed/simple; bh=sF2ICiiN414m0J4M2ocE7ExDu+pSp4IruxrnQG44i+E=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=hDuRObZhlDQHUbcbfikamLyJG5lIv9/dVdfBuy6H9ZyOQYUW3k5WpVw+Bm8SxlS2lRKTKNvHygEzlohr2mZBrqPo68lfmNG9N4dMt6LIGza3nTKg/r950i7OBp31Tt7hSqZW5wwIudrSQSJwXcX91sQAOxFNOYcFoxOURlBaeAw= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from eig-obgw-6003a.ext.cloudfilter.net ([10.0.30.151]) by cmsmtp with ESMTPS id OIZkrgXxACF6GOMAerzMSF; Fri, 12 Jan 2024 18:22:20 +0000 Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with ESMTPS id OMAdrkaTqtzh2OMAdrrqzv; Fri, 12 Jan 2024 18:22:20 +0000 X-Authority-Analysis: v=2.4 cv=Ra6Dtnhv c=1 sm=1 tr=0 ts=65a1835c a=ApxJNpeYhEAb1aAlGBBbmA==:117 a=ApxJNpeYhEAb1aAlGBBbmA==:17 a=OWjo9vPv0XrRhIrVQ50Ab3nP57M=:19 a=dLZJa+xiwSxG16/P+YVxDGlgEgI=:19 a=dEuoMetlWLkA:10 a=Qbun_eYptAEA:10 a=98DCmW50fwCByoidvUoA:9 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tromey.com; s=default; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date:References :Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=oQQHfJ52VYxtdUBN7woTo4HrAWVVFzOY8SyYXlpkafo=; b=mqgIWMx2Ci7jV6/Ifllnqezmpw fyC2Y+v8TJSeYmrk/Fi+b9kPDY6gItbiqR7CCdUySK2G5vJhdIZ+ji89wNtkEe6uYIzLtS958240a a9mRpFNrjRYuQT51fZr+MoZQp; Received: from 97-122-68-157.hlrn.qwest.net ([97.122.68.157]:50532 helo=murgatroyd) by box5379.bluehost.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96.2) (envelope-from ) id 1rOMAd-000IsA-0s; Fri, 12 Jan 2024 11:22:19 -0700 From: Tom Tromey To: Simon Marchi Cc: Tom Tromey , gdb-patches@sourceware.org Subject: Re: [PATCH 00/19] Add hash table to gdbsupport References: <20230407-t-robin-hood-hash-v1-0-900d93ef1510@tromey.com> <87jzpoft0q.fsf@tromey.com> <87v87zpwuw.fsf@tromey.com> X-Attribution: Tom Date: Fri, 12 Jan 2024 11:22:17 -0700 In-Reply-To: (Simon Marchi's message of "Thu, 11 Jan 2024 21:57:01 -0500") Message-ID: <87r0imo1ie.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - box5379.bluehost.com X-AntiAbuse: Original Domain - sourceware.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tromey.com X-BWhitelist: no X-Source-IP: 97.122.68.157 X-Source-L: No X-Exim-ID: 1rOMAd-000IsA-0s X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 97-122-68-157.hlrn.qwest.net (murgatroyd) [97.122.68.157]:50532 X-Source-Auth: tom+tromey.com X-Email-Count: 2 X-Org: HG=bhshared;ORG=bluehost; X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTM3OS5ibHVlaG9zdC5jb20= X-Local-Domain: yes X-CMAE-Envelope: MS4xfIdiqGDdceiZfBDb5qhlFc0Mw00bntoLRfDl62t+2xWL4K1jpeKs/w84BlyA4N7jVjz53EqOVloqRWpG3M6tkDKp1opuOmscQ9AyxeCOriS7NyvjpJC2 mA7SXS66luHBJbPViC8Kv5EKsisugzVq8Annsutz/yqf1bgy2FK+80nfhioZXyS5MgdacB608IRSZKBGk+yjUoeWEdcf9f9n9E4= X-Spam-Status: No, score=-3016.3 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,JMQ_SPF_NEUTRAL,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Simon> I spent a bit of time reading the interface of your hash table, and that Simon> was a point I found unfortunate. The type V must have a default Simon> constructor and an "empty" state (I guess that's what you mean by Simon> sentinel), even if it doesn't make sense for the rest of the program. It's maybe worth noting that this is not a step backward from htab_t, which only stores pointers. Simon> How do other implementations (of open addessing hash tables) typically Simon> deal with this? From what I recally, other implementations I have used Simon> in the past didn't have this requirement. I don't know in general. I looked at one and it uses a separate vector of flag bytes to indicate which values are valid. Simon> And that makes me think that a question I did not see answered is: I Simon> don't want to undermine your work, but what is the rationale for Simon> implementing it ourselves? In my view, integrating an external C++ package like this is pain both legally (at least, you have to find one with the appropriate license) and technically. Even just trying to integrate the GCC hash table was a pain. The typical problem, IMO, is that it's unusual to write a standalone class like this, instead one introduces dependencies on a variety of other things. Tom