Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed4a.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.064 X-Spam-Evidence: '*H*': 0.87; '*S*': 0.00; '64-bit': 0.07; 'over,': 0.07; 'versions,': 0.07; '32-bit': 0.09; 'subject:skip:t 10': 0.09; 'cc:addr:python-list': 0.11; "wouldn't": 0.14; 'windows': 0.15; 'chatting': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'reasonably': 0.16; 'rollovers': 0.16; 'wrote:': 0.18; 'cc:addr:python.org': 0.22; 'cc:2**0': 0.24; 'header:In- Reply-To:1': 0.27; 'function': 0.29; 'am,': 0.29; 'scale': 0.29; 'dec': 0.30; 'newer': 0.30; 'message-id:@mail.gmail.com': 0.30; 'about.': 0.31; 'quite': 0.32; 'entirely': 0.33; 'fri,': 0.33; 'older': 0.33; 'reader': 0.33; 'could': 0.34; 'hundreds': 0.35; 'but': 0.35; 'received:google.com': 0.35; 'ones,': 0.36; 'reflect': 0.36; 'shorter': 0.36; 'previous': 0.38; 'does': 0.39; 'sure': 0.39; 'according': 0.40; 'days': 0.60; 'even': 0.60; 'ian': 0.60; 'details.': 0.61; 'information': 0.63; 'more': 0.64; 'between': 0.67; 'believe': 0.68; 'safe': 0.72; 'lack': 0.78; 'believe,': 0.84; 'irrelevant': 0.84; 'rolls': 0.84; 'subject:over': 0.84; 'involved.': 0.91; 'to:none': 0.92 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc :content-type; bh=J4YZwQBgXe9D4eiluBBxbRsOq6EFbTxYuWSWHfC1B/4=; b=OAWd/MBmgjzNWNyLi1539MsHU3JPcpU4LQhkfWYFG4e9bk4ZY3Oy1p0Zg52pZyGzn6 U62Lb24VlE73eQllMaIXAH7qFAC2GTzbEZ0L2+s/s7z0/iW0aYb543dGvZ8Nc3gReX4u BdOU5hUHTkG0WKzTUPR4XW6YFYnYkA7BCoY8Ll1PUtNC9plbJffZhFDiyxk0O6niA/sE 4ElxTRzA9Vblj7edU26lV5UPHGqV3CCFfY6rX2ETV5MCR26CxM97H6aJQnoZ+7hhgpQK P8Y0VOTXvmfKKBQDuuJ9eIjECf+qZSCRR9KUBcSG9SJffEhAk0iGZsXpiDgJpgebgi9U Ut0w== MIME-Version: 1.0 X-Received: by 10.107.17.79 with SMTP id z76mr10169397ioi.27.1417709568584; Thu, 04 Dec 2014 08:12:48 -0800 (PST) In-Reply-To: References: <54807cfd$0$2311$426a74cc@news.free.fr> <87vblr8lcw.fsf@elektro.pacujo.net> Date: Fri, 5 Dec 2014 03:12:48 +1100 Subject: Re: time.monotonic() roll over From: Chris Angelico Cc: Python Content-Type: text/plain; charset=UTF-8 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 28 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1417709577 news.xs4all.nl 2839 [2001:888:2000:d::a6]:44058 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:81916 On Fri, Dec 5, 2014 at 3:05 AM, Ian Kelly wrote: > On Dec 4, 2014 8:56 AM, "Marko Rauhamaa" wrote: >> >> "ast" : >> >> > Does any body know when time.monotonic() rolls over ? >> >> Never, according to the documentation you linked. >> >> Admittedly, the documentation confuses the reader by chatting about some >> irrelevant internal Windows details. > > Not entirely irrelevant. The implication is that if you go more than 49 days > without calling the function on old Windows systems, rollovers could be > missed, which is good to know about. The result would still be monotonic, > but it wouldn't accurately reflect the time elapsed. I don't know for sure about the newer Windowses, but I believe they use a 64-bit counter instead of the 32-bit one used in previous versions, so even if they do roll over, there'll be a much MUCH longer time scale involved. Even if it stores time in nanoseconds, a 64-bit counter would allow for hundreds of years between rollovers, which is reasonably safe - much better than the month-and-a-bit of older ones, which is shorter than quite a lot of my programs' uptimes. Hence the lack of information about them; you don't have to worry. (Likewise on Unix-derived systems, I believe, and for the same reason.) ChrisA