From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from localhost (localhost [127.0.0.1]) by olra.theworths.org (Postfix) with ESMTP id ACCF2431FAF for ; Thu, 1 Mar 2012 10:11:51 -0800 (PST) X-Virus-Scanned: Debian amavisd-new at olra.theworths.org X-Spam-Flag: NO X-Spam-Score: -0.7 X-Spam-Level: X-Spam-Status: No, score=-0.7 tagged_above=-999 required=5 tests=[RCVD_IN_DNSWL_LOW=-0.7] autolearn=disabled Received: from olra.theworths.org ([127.0.0.1]) by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id kLYa-Tvqif06 for ; Thu, 1 Mar 2012 10:11:48 -0800 (PST) Received: from dmz-mailsec-scanner-8.mit.edu (DMZ-MAILSEC-SCANNER-8.MIT.EDU [18.7.68.37]) by olra.theworths.org (Postfix) with ESMTP id 03FB9431FAE for ; Thu, 1 Mar 2012 10:11:47 -0800 (PST) X-AuditID: 12074425-b7f4a6d0000008e0-d3-4f4fbbe36361 Received: from mailhub-auth-1.mit.edu ( [18.9.21.35]) by dmz-mailsec-scanner-8.mit.edu (Symantec Messaging Gateway) with SMTP id D3.66.02272.3EBBF4F4; Thu, 1 Mar 2012 13:11:47 -0500 (EST) Received: from outgoing.mit.edu (OUTGOING-AUTH.MIT.EDU [18.7.22.103]) by mailhub-auth-1.mit.edu (8.13.8/8.9.2) with ESMTP id q21IBhnl025827; Thu, 1 Mar 2012 13:11:44 -0500 Received: from awakening.csail.mit.edu (awakening.csail.mit.edu [18.26.4.91]) (authenticated bits=0) (User authenticated as amdragon@ATHENA.MIT.EDU) by outgoing.mit.edu (8.13.6/8.12.4) with ESMTP id q21IBf9R025475 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=NOT); Thu, 1 Mar 2012 13:11:43 -0500 (EST) Received: from amthrax by awakening.csail.mit.edu with local (Exim 4.77) (envelope-from ) id 1S3ATd-0001PR-JP; Thu, 01 Mar 2012 13:11:41 -0500 Date: Thu, 1 Mar 2012 13:11:41 -0500 From: Austin Clements To: Justus Winter <4winter@informatik.uni-hamburg.de> Subject: Re: [PATCH] Actually close the xapian database in notmuch_database_close Message-ID: <20120301181141.GA4797@mit.edu> References: <1330507157-22859-1-git-send-email-4winter@informatik.uni-hamburg.de> <1330507157-22859-2-git-send-email-4winter@informatik.uni-hamburg.de> <20120229154833.GB772@mit.edu> <20120229211922.GQ24964@survex.com> <20120229221754.GD772@mit.edu> <20120301065930.5076.72748@thinkbox.jade-hamburg.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120301065930.5076.72748@thinkbox.jade-hamburg.de> User-Agent: Mutt/1.5.21 (2010-09-15) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupjleLIzCtJLcpLzFFi42IR4hRV1n2829/foPOGsMXs1h9MFtdvzmS2 uL/8PasDs8fE86fZPJ6tusXssW7nH/YA5igum5TUnMyy1CJ9uwSujKVTnrEXdIhU/F5+mamB 8Qd/FyMnh4SAicTys7PZIWwxiQv31rN1MXJxCAnsY5S4feIrC4SznlFi9vwHzBDOCSaJi2/n sEM4Sxglrh7uZQbpZxFQkXjWOQHMZhPQkNi2fzkjiC0iYCqx4cEDsB3MApYSV2dMYwWxhQWC JU5NPs0GYvMKaEscnn+XBcQWEtjBJLHvTSREXFDi5MwnLBC9WhI3/r1k6mLkALKlJZb/4wAJ cwo4SrRumghWIgp0wpST29gmMArNQtI9C0n3LITuBYzMqxhlU3KrdHMTM3OKU5N1i5MT8/JS i3Qt9HIzS/RSU0o3MYKCnd1FdQfjhENKhxgFOBiVeHi9Jvr7C7EmlhVX5h5ilORgUhLlrd8J FOJLyk+pzEgszogvKs1JLT7EKMHBrCTCK9UPlONNSaysSi3Kh0lJc7AoifNqar3zExJITyxJ zU5NLUgtgsnKcHAoSfAqAqNaSLAoNT21Ii0zpwQhzcTBCTKcB2i4GkgNb3FBYm5xZjpE/hSj opQ4ryhIQgAkkVGaB9cLS0avGMWBXhHmNQap4gEmMrjuV0CDmYAGL77sBzK4JBEhJdXAePYu w4O1ZvPVHy3xyfk3YY1jbhPPw/y7cetOOu2xe1nQt/CJXKWWrssHFz4Gdf/qNe5nGZ+qLVUM tr6/h3t2UnHG89N3uZ4fme3+bc7ifz/LH50V3MKe8LLrofmDW3pq2+ViZ7//r+NmayMd7HPl 1ZUXOcE1FxtzAoUZVRwea1cZLlXYVLfzqxJLcUaioRZzUXEiAB8BTUAhAwAA Cc: Olly Betts , notmuch@notmuchmail.org X-BeenThere: notmuch@notmuchmail.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: "Use and development of the notmuch mail system." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Mar 2012 18:11:51 -0000 Quoth Justus Winter on Mar 01 at 7:59 am: > Quoting Austin Clements (2012-02-29 23:17:54) > >Quoth Olly Betts on Feb 29 at 9:19 pm: > >> On Wed, Feb 29, 2012 at 10:48:33AM -0500, Austin Clements wrote: > >> > Quoth Justus Winter on Feb 29 at 10:19 am: > >> > > Formerly the xapian database object was deleted and closed in its > >> > > destructor once the object was garbage collected. Explicitly call > >> > > close() so that the database and the associated lock is released > >> > > immediately. > >> > > >> > Interesting. Is this a bug in Xapian? According to the docs, > >> > ~Database is supposed to close the database (if there are no other > >> > copies, which there shouldn't be), so this should be redundant with > >> > the delete notmuch->xapian_db a few lines down, but your experience > >> > obviously suggests that it isn't and I can't find the code path in > >> > Xapian that would close it in the destructor. > >> > >> Most Xapian API classes (including Database and WritableDatabase) just > >> hold a reference-counted pointer, and so it's the destructor of the > >> reference-counted object which closes the database. If "PIMPL" means > >> anything to you, that's what we have here. > >> > >> Some other API classes objects (such as PostingIterator) internally hold > >> a reference to the database they are using, so calling close() > >> explicitly is useful if you don't want to have to worry about such > >> objects still existing and holding onto references which keep the > >> database open. > > > >Makes sense. Justus, could you add a comment to your patch explaining > >that we explicitly close the database because there may be other > >objects with references to it that would keep it open? > > I thought I did, I'm not a native speaker though, so if you want to > reword my message be my guest ;) Sorry, I meant a code comment. Perhaps something like, /* Many Xapian objects (and thus notmuch objects) hold references to * the database, so merely deleting the database may not suffice to * close it. Thus, we explicitly close it here. */ > >Also, since close could throw an exception, it should get wrapped in a > >try/catch like flush currently is. > > My interpretation of [0] was that Xapian::Database::close() does not > throw any exceptions. Olly mentioned on IRC that it can throw an exception (because, for example, close calls flush). > Cheers, > Justus > > 0: http://xapian.org/docs/apidoc/html/classXapian_1_1Database.html#59f5f8b137723dcaaabdbdccbc0cf1eb