From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx.kolabnow.com (mx.kolabnow.com [95.128.36.41]) by sourceware.org (Postfix) with ESMTPS id 068F7396E854 for ; Wed, 2 Jun 2021 15:03:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 068F7396E854 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=appliantology.com Authentication-Results: sourceware.org; spf=none smtp.mailfrom=appliantology.com Received: from localhost (unknown [127.0.0.1]) by ext-mx-out003.mykolab.com (Postfix) with ESMTP id 22A1D40DC3; Wed, 2 Jun 2021 17:03:55 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kolabnow.com; h= message-id:references:in-reply-to:subject:subject:from:from:date :date:content-transfer-encoding:content-type:content-type :mime-version:received:received:received; s=dkim20160331; t= 1622646231; x=1624460632; bh=sp+/JHEMsB0PcQPA7Px4uOw0Yzd7DejF8cW aZ7JOoNc=; b=AqT0e94vl31JcpR93IerbkMMWhN5YQPcHA692AjmTBy+vvYtqJS 1GyBIjbgm33mVFImn81tIiEPw1phTgElAY0TKkGWkUuJy3EMITlNcaD75FRUbA44 uef+i0Xi5rF4kz8lHrYPL+WOPykQk8C7r4qVr2NFC8V1/8jMQ2FlwQ0c1dxPs0M3 r85Z4QIH3ulM6679gjT5OqIHDKrisrLUURu0iIEdQR6Z14ApTt8uBmNQdO7qWLOe lEAGP9ql7Lc0aT7Fx8YCe/mdzxGg0XqR1bI6DZEdqp1OM2T9PaanxgXoft4gd13T zCyulN1U6/fxDBheG4wlyvgkkdCaR+sVIuVQcV5WD6yvQPOf/UFtiC6kOHBwB+J2 wVWgE2bFrMJthKwyN/2/we56q0jux1k+LyZ64lbpa8ROmOYvz+EeAcTAifr/Gw+S fkDK83ma3XrFmDhshhL1wqnKrtI44m5SwZaOMOK9QgF7TiIkMEiXz9X8+ifKpWfu Us6hpuqOiF2+MQyGxnn9N3Yf1vVkQsVL/atm4YTQVGCnS2IPCZcTcF3Gu0D2WKlJ cW0aora1FgmBOHHmaGwCxCZixDrtBDohyjSZEWt+2m+fpTt3MFSRfgZxmpMEV6Ql JA0SbQK/YmY+GZ6UrcR/F+IugwsJbgOhdw8+XdrLllcfyUQZAJ5Ro5dU= X-Virus-Scanned: amavisd-new at mykolab.com X-Spam-Score: -1.899 X-Spam-Level: X-Spam-Status: No, score=-5.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.2 Received: from mx.kolabnow.com ([127.0.0.1]) by localhost (ext-mx-out003.mykolab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id VgEBoSrFJeKI; Wed, 2 Jun 2021 17:03:51 +0200 (CEST) Received: from int-mx001.mykolab.com (unknown [10.9.13.1]) by ext-mx-out003.mykolab.com (Postfix) with ESMTPS id 0722840294; Wed, 2 Jun 2021 17:03:50 +0200 (CEST) Received: from int-subm002.mykolab.com (unknown [10.9.37.2]) by int-mx001.mykolab.com (Postfix) with ESMTPS id 09E035B6; Wed, 2 Jun 2021 17:03:49 +0200 (CEST) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 02 Jun 2021 08:03:47 -0700 From: Thomas Rodgers To: Mikhail Matrosov Cc: Jonathan Wakely , libstdc++ Subject: Re: std::atomic_shared_ptr In-Reply-To: References: <6e2006356de7157302748c8cf7a9dc48@appliantology.com> Message-ID: X-Sender: rodgert@appliantology.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Jun 2021 15:04:07 -0000 On 2021-06-02 07:37, Mikhail Matrosov wrote: >> Probably not, because it would require ABI-breaking changes to > std::shared_ptr, which is out of the question. > > Could you please elaborate on that? I can see how folly uses > std::shared_ptr directly: > > https://github.com/facebook/folly/blob/master/folly/concurrency/AtomicSharedPtr.h#L76 > https://github.com/facebook/folly/blob/master/folly/concurrency/detail/AtomicSharedPtr-detail.h#L45 > > ----- > Best regards, Mikhail Matrosov I've yet to be convinced that this type warrants the extra complexity doing so would entail, and if I did decide to incur that level of complexity, I would likely go a different route (see comments in folly re: corner cases). Either way, GCC12 won't commit to any ABI for this, GCC13 might, and the details can change between the two releases.