From: Austin Clements Date: Thu, 2 Oct 2014 19:19:08 +0000 (+2000) Subject: [PATCH v4] lib: Simplify close and codify aborting atomic section X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=7c72e45daa4a02320a4e7bac5bcebc52385f22b5;p=notmuch-archives.git [PATCH v4] lib: Simplify close and codify aborting atomic section --- diff --git a/46/8cb4578c6fb730bbf9595abfaa51aa87e0dd4b b/46/8cb4578c6fb730bbf9595abfaa51aa87e0dd4b new file mode 100644 index 000000000..2aaeca442 --- /dev/null +++ b/46/8cb4578c6fb730bbf9595abfaa51aa87e0dd4b @@ -0,0 +1,178 @@ +Return-Path: +X-Original-To: notmuch@notmuchmail.org +Delivered-To: notmuch@notmuchmail.org +Received: from localhost (localhost [127.0.0.1]) + by olra.theworths.org (Postfix) with ESMTP id 1B31A431FC0 + for ; Thu, 2 Oct 2014 12:19:21 -0700 (PDT) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: -2.3 +X-Spam-Level: +X-Spam-Status: No, score=-2.3 tagged_above=-999 required=5 + tests=[RCVD_IN_DNSWL_MED=-2.3] 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 h5OeBDRD08fY for ; + Thu, 2 Oct 2014 12:19:17 -0700 (PDT) +Received: from dmz-mailsec-scanner-5.mit.edu (dmz-mailsec-scanner-5.mit.edu + [18.7.68.34]) + by olra.theworths.org (Postfix) with ESMTP id 1D9B1431FB6 + for ; Thu, 2 Oct 2014 12:19:17 -0700 (PDT) +X-AuditID: 12074422-f79436d000000c21-28-542da534ddd0 +Received: from mailhub-auth-4.mit.edu ( [18.7.62.39]) + (using TLS with cipher AES256-SHA (256/256 bits)) + (Client did not present a certificate) + by dmz-mailsec-scanner-5.mit.edu (Symantec Messaging Gateway) with SMTP + id AF.23.03105.435AD245; Thu, 2 Oct 2014 15:19:16 -0400 (EDT) +Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) + by mailhub-auth-4.mit.edu (8.13.8/8.9.2) with ESMTP id s92JJEoM022339; + Thu, 2 Oct 2014 15:19:14 -0400 +Received: from drake.dyndns.org (26-4-182.dynamic.csail.mit.edu [18.26.4.182]) + (authenticated bits=0) + (User authenticated as amdragon@ATHENA.MIT.EDU) + by outgoing.mit.edu (8.13.8/8.12.4) with ESMTP id s92JJBXw006342 + (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT); + Thu, 2 Oct 2014 15:19:13 -0400 +Received: from amthrax by drake.dyndns.org with local (Exim 4.84) + (envelope-from ) + id 1XZluB-0000uZ-Kh; Thu, 02 Oct 2014 15:19:11 -0400 +From: Austin Clements +To: notmuch@notmuchmail.org +Subject: [PATCH v4] lib: Simplify close and codify aborting atomic section +Date: Thu, 2 Oct 2014 15:19:08 -0400 +Message-Id: <1412277548-3445-1-git-send-email-aclements@csail.mit.edu> +X-Mailer: git-send-email 2.1.0 +In-Reply-To: <87mw9ee0vf.fsf@csail.mit.edu> +References: <87mw9ee0vf.fsf@csail.mit.edu> +X-Brightmail-Tracker: + H4sIAAAAAAAAA+NgFjrGIsWRmVeSWpSXmKPExsUixG6nrmuyVDfEYHO/msWN1m5Gi+s3ZzJb + XFlznt2B2ePZqlvMHlsOvWf22P39J0sAcxSXTUpqTmZZapG+XQJXxuXWXywFR5QqHtxex9jA + +Fi6i5GTQ0LARKJh2WpWCFtM4sK99WwgtpDAbCaJ5b8ruxi5gOwNjBKvJ61ihUgcZpKYuIYT + IrGEUWLBz+csIAk2AX2JFWsngRWJCEhL7Lw7G8xmFvCWmP11NTuILSzgJbGt7QIziM0ioCpx + bcsLMJtXwE1i644j7BBXyEls2P2fEcTmFNCWWPN1FjPEYi2J1s4+9gmM/AsYGVYxyqbkVunm + JmbmFKcm6xYnJ+blpRbpmurlZpbopaaUbmIEB5eL0g7GnweVDjEKcDAq8fBmNOiECLEmlhVX + 5h5ilORgUhLl/bFQN0SILyk/pTIjsTgjvqg0J7X4EKMEB7OSCK9wN1CONyWxsiq1KB8mJc3B + oiTOu+kHX4iQQHpiSWp2ampBahFMVoaDQ0mCd/d8oEbBotT01Iq0zJwShDQTByfIcB6g4THT + QYYXFyTmFmemQ+RPMSpKifNyzgNKCIAkMkrz4Hph0f+KURzoFWHeaJB2HmDigOt+BTSYCWjw + O3uwwSWJCCmpBkbJ4sTEXucTLmc7J+k+Kyn0r//oucd6Unvrli0am3//X/F4tvhpyZiTcXKZ + bpHrSq6rrYgW/JuiwuKh0+q2233ZTGvvd7/+/r/xX6wpILom3TL7vsn0cDfvC3Xnvk/MVeQw + u9oc1N/UdVXhy6qXszccOVijoJjvI2Xmtl59zaJOu84AbcYLE5RYijMSDbWYi4oTAUuMhoPZ AgAA +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, 02 Oct 2014 19:19:21 -0000 + +From: Austin Clements + +In Xapian, closing a database implicitly aborts any outstanding +transaction and commits changes. For historical reasons, +notmuch_database_close had grown to almost, but not quite duplicate +this behavior. Before closing the database, it would explicitly (and +unnecessarily) commit it. However, if there was an outstanding +transaction (ie atomic section), commit would throw a Xapian +exception, which notmuch_database_close would unnecessarily print to +stderr, even though notmuch_database_close would ultimately abort the +transaction anyway when it called close. + +This patch simplifies notmuch_database_close to explicitly abort any +outstanding transaction and then just call Database::close. This +works for both read-only and read/write databases, takes care of +committing changes, unifies the exception handling path, and codifies +aborting outstanding transactions. This is currently the only way to +abort an atomic section (and may remain so, since it would be +difficult to roll back things we may have cached from rolled-back +modifications). +--- + lib/database.cc | 32 +++++++++++++++++--------------- + lib/notmuch.h | 9 ++++++++- + 2 files changed, 25 insertions(+), 16 deletions(-) + +diff --git a/lib/database.cc b/lib/database.cc +index a3a7cd3..a47a71d 100644 +--- a/lib/database.cc ++++ b/lib/database.cc +@@ -903,28 +903,30 @@ notmuch_database_close (notmuch_database_t *notmuch) + { + notmuch_status_t status = NOTMUCH_STATUS_SUCCESS; + +- try { +- if (notmuch->xapian_db != NULL && +- notmuch->mode == NOTMUCH_DATABASE_MODE_READ_WRITE) +- (static_cast (notmuch->xapian_db))->flush (); +- } catch (const Xapian::Error &error) { +- status = NOTMUCH_STATUS_XAPIAN_EXCEPTION; +- if (! notmuch->exception_reported) { +- fprintf (stderr, "Error: A Xapian exception occurred flushing database: %s\n", +- error.get_msg().c_str()); +- } +- } +- + /* 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. */ + if (notmuch->xapian_db != NULL) { + try { ++ /* If there's an outstanding transaction, it's unclear if ++ * closing the Xapian database commits everything up to ++ * that transaction, or may discard committed (but ++ * unflushed) transactions. To be certain, explicitly ++ * cancel any outstanding transaction before closing. */ ++ if (notmuch->mode == NOTMUCH_DATABASE_MODE_READ_WRITE && ++ notmuch->atomic_nesting) ++ (static_cast (notmuch->xapian_db)) ++ ->cancel_transaction (); ++ ++ /* Close the database. This implicitly flushes ++ * outstanding changes. */ + notmuch->xapian_db->close(); + } catch (const Xapian::Error &error) { +- /* don't clobber previous error status */ +- if (status == NOTMUCH_STATUS_SUCCESS) +- status = NOTMUCH_STATUS_XAPIAN_EXCEPTION; ++ status = NOTMUCH_STATUS_XAPIAN_EXCEPTION; ++ if (! notmuch->exception_reported) { ++ fprintf (stderr, "Error: A Xapian exception occurred closing database: %s\n", ++ error.get_msg().c_str()); ++ } + } + } + +diff --git a/lib/notmuch.h b/lib/notmuch.h +index fe2340b..dae0416 100644 +--- a/lib/notmuch.h ++++ b/lib/notmuch.h +@@ -281,7 +281,7 @@ notmuch_database_open (const char *path, + notmuch_database_t **database); + + /** +- * Close the given notmuch database. ++ * Commit changes and close the given notmuch database. + * + * After notmuch_database_close has been called, calls to other + * functions on objects derived from this database may either behave +@@ -292,6 +292,13 @@ notmuch_database_open (const char *path, + * notmuch_database_close can be called multiple times. Later calls + * have no effect. + * ++ * For writable databases, notmuch_database_close commits all changes ++ * to disk before closing the database. If the caller is currently in ++ * an atomic section (there was a notmuch_database_begin_atomic ++ * without a matching notmuch_database_end_atomic), this will discard ++ * changes made in that atomic section (but still commit changes made ++ * prior to entering the atomic section). ++ * + * Return value: + * + * NOTMUCH_STATUS_SUCCESS: Successfully closed the database. +-- +2.1.0 +