From jira-return-11638-archive-asf-public=cust-asf.ponee.io@kafka.apache.org Mon Apr 9 05:13:06 2018 Return-Path: X-Original-To: archive-asf-public@cust-asf.ponee.io Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by mx-eu-01.ponee.io (Postfix) with SMTP id A78C1180638 for ; Mon, 9 Apr 2018 05:13:05 +0200 (CEST) Received: (qmail 51641 invoked by uid 500); 9 Apr 2018 03:13:04 -0000 Mailing-List: contact jira-help@kafka.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: jira@kafka.apache.org Delivered-To: mailing list jira@kafka.apache.org Received: (qmail 51629 invoked by uid 99); 9 Apr 2018 03:13:04 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd3-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 09 Apr 2018 03:13:04 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd3-us-west.apache.org (ASF Mail Server at spamd3-us-west.apache.org) with ESMTP id F154418048D for ; Mon, 9 Apr 2018 03:13:03 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd3-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: -110.311 X-Spam-Level: X-Spam-Status: No, score=-110.311 tagged_above=-999 required=6.31 tests=[ENV_AND_HDR_SPF_MATCH=-0.5, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01, USER_IN_DEF_SPF_WL=-7.5, USER_IN_WHITELIST=-100] autolearn=disabled Received: from mx1-lw-eu.apache.org ([10.40.0.8]) by localhost (spamd3-us-west.apache.org [10.40.0.10]) (amavisd-new, port 10024) with ESMTP id IL5Rsz_egbrA for ; Mon, 9 Apr 2018 03:13:03 +0000 (UTC) Received: from mailrelay1-us-west.apache.org (mailrelay1-us-west.apache.org [209.188.14.139]) by mx1-lw-eu.apache.org (ASF Mail Server at mx1-lw-eu.apache.org) with ESMTP id 4F7795FBEC for ; Mon, 9 Apr 2018 03:13:02 +0000 (UTC) Received: from jira-lw-us.apache.org (unknown [207.244.88.139]) by mailrelay1-us-west.apache.org (ASF Mail Server at mailrelay1-us-west.apache.org) with ESMTP id 9EBC8E0B13 for ; Mon, 9 Apr 2018 03:13:00 +0000 (UTC) Received: from jira-lw-us.apache.org (localhost [127.0.0.1]) by jira-lw-us.apache.org (ASF Mail Server at jira-lw-us.apache.org) with ESMTP id 2CC3521209 for ; Mon, 9 Apr 2018 03:13:00 +0000 (UTC) Date: Mon, 9 Apr 2018 03:13:00 +0000 (UTC) From: "Guozhang Wang (JIRA)" To: jira@kafka.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (KAFKA-2607) Review `Time` interface and its usage MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/KAFKA-2607?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16429975#comment-16429975 ] Guozhang Wang commented on KAFKA-2607: -------------------------------------- Thanks for sharing Ismael. This is a great read. I vaguely remember in J7 the perf difference of nanoTime is indeed non-negligible, but I cannot find the source of my memory now... > Review `Time` interface and its usage > ------------------------------------- > > Key: KAFKA-2607 > URL: https://issues.apache.org/jira/browse/KAFKA-2607 > Project: Kafka > Issue Type: Improvement > Affects Versions: 0.11.0.0, 1.0.0 > Reporter: Ismael Juma > Priority: Major > Labels: newbie > > Two of `Time` interface's methods are `milliseconds` and `nanoseconds` which are implemented in `SystemTime` as follows: > {code} > @Override > public long milliseconds() { > return System.currentTimeMillis(); > } > @Override > public long nanoseconds() { > return System.nanoTime(); > } > {code} > The issue with this interface is that it makes it seem that the difference is about the unit (`ms` versus `ns`) whereas it's much more than that: > https://blogs.oracle.com/dholmes/entry/inside_the_hotspot_vm_clocks > We should probably change the names of the methods and review our usage to see if we're using the right one in the various places. -- This message was sent by Atlassian JIRA (v7.6.3#76005)