From owner-freebsd-toolchain@freebsd.org Mon Feb 11 14:41:27 2019 Return-Path: Delivered-To: freebsd-toolchain@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A5CD614D8DA3 for ; Mon, 11 Feb 2019 14:41:27 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 0A3976FFC2 for ; Mon, 11 Feb 2019 14:41:26 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id x1BEfIWl046824 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 11 Feb 2019 16:41:21 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua x1BEfIWl046824 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id x1BEfIot046823; Mon, 11 Feb 2019 16:41:18 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Mon, 11 Feb 2019 16:41:18 +0200 From: Konstantin Belousov To: Banta Plan Cc: "freebsd-toolchain@freebsd.org" Subject: Re: Problem with mutex.lock() Message-ID: <20190211144118.GZ24863@kib.kiev.ua> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.2 (2019-01-07) X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FROM, NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on tom.home X-BeenThere: freebsd-toolchain@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Maintenance of FreeBSD's integrated toolchain List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 11 Feb 2019 14:41:27 -0000 On Mon, Feb 11, 2019 at 02:04:38PM +0000, Banta Plan wrote: > I think you can reduce the problem to: > ## > int main() { > std::mutex m; > m.lock(); > m.lock(); > > return 0; > } > ## > > This should deadlock. Where is it specified that the program should deadlock ? The behaviour for this case is undefined. > But this will crash the program. Which is not disallowed by standard.