From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 726423858D3C for ; Fri, 11 Mar 2022 13:58:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 726423858D3C Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-458-uGV_PhobM2SCGpjCIEh7Bw-1; Fri, 11 Mar 2022 08:58:55 -0500 X-MC-Unique: uGV_PhobM2SCGpjCIEh7Bw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D721DFC80; Fri, 11 Mar 2022 13:58:54 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.88]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0974A7A3F3; Fri, 11 Mar 2022 13:58:53 +0000 (UTC) From: Florian Weimer To: David Mozes Cc: "libc-help@sourceware.org" Subject: Re: rwlock different behavior on glibc 2.28 then on previous versions References: Date: Fri, 11 Mar 2022 14:58:51 +0100 In-Reply-To: (David Mozes's message of "Mon, 7 Mar 2022 20:13:26 +0000") Message-ID: <87czis1tgk.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-5.9 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H5, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-help@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-help mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Mar 2022 13:58:58 -0000 * David Mozes: > On the previous version of Glibc (before the commit) We could release > write lock with different thread as the one that owned the lock (If we > like) . Sorry, this misuse of the API has always been undefined according to POSIX (=E2=80=9CResults are undefined if the read-write lock rwlock is not = held by the calling thread.=E2=80=9D). > This is help very much for async program that has a many threads that > communicate with some target. And we like to define a call back > function instead of blocking on aio thread that send the data in order > to release the rwlock.this improves the performance dramatically . Could you use a different synchronization object (perhaps a condition variable)? Thanks, Florian