From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mellona.thatsmathematics.com (mellona.thatsmathematics.com [IPv6:2001:4801:7825:103:be76:4eff:fe10:2a2b]) by sourceware.org (Postfix) with ESMTPS id 904F03860763; Thu, 14 Dec 2023 23:30:10 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 904F03860763 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=thatsmathematics.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=thatsmathematics.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 904F03860763 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2001:4801:7825:103:be76:4eff:fe10:2a2b ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1702596612; cv=none; b=if1kaAGLpGJFFzO/wKGRL4W8QIV/S8hVbbkjkpyBjB0fvYJCeNrt2DIstzyN3e3vn4PrJ7Pct4YnAEhbP/HrcjpQt5u/BdyiZv3SzvZNJuDo65hp8N7Em4+iZMEHq9XdohqZKhC0aOyI4Zyuc3MMrv+j/psBZWzPrrYnPhxocIU= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1702596612; c=relaxed/simple; bh=/lwq7TA2Lw6pPsWxq0vYWZ5A4jcjvB7X1mtkcXuo/PA=; h=DKIM-Signature:Date:From:To:Subject:Message-ID:MIME-Version; b=rj5V0oOcidocHuFQThl9y3U3T+yOdsAy+6t73KMjcvtrS93jSmmh+W829wsBN28ymoQhXfJJ9I7JBVspPh3Qljnw0YYuxU3CLcAzvaEM7nsn6bAA1zNlpk0ms1RiDSJ8OPF3vgxQdwqCaBec3w7ylL8yhjpralwZ/CvvtXAfwKk= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=thatsmathematics.com; s=condor; t=1702596609; bh=/lwq7TA2Lw6pPsWxq0vYWZ5A4jcjvB7X1mtkcXuo/PA=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=1E5gUpqLHelcWb4rF/xYrjcntfopKtHB9KHBry8pIUmvPasTVKDIUJis6a8Sz+QZP Q/E3B/UFEN3AHofI5/ZUlRx6fJsd2OC7rC7vaqmC4THSl3oPSSTguzoS0ZNStYziOb Ifi7NfEm71cZ2yR+8cbJ5+SBMJH5CWoJTmkmWS/2SxbDPPG3mCGAIsArmwIJwVp7ce HIIShrb5wwBEC0nveYT0Ll+9+DD0jdg+rSPuMOZky+edJKcaG0mWe/wfE2yPSQQZjO sSuhQggTHOyfZ0LDAlwStvHnzGu9wNkLXTwpAb7yK22ZhWjaxyz2n9ko39tVYYSsg3 6AQmrqXGDjXvQ== Received: from moneta.lan (c-67-177-244-133.hsd1.co.comcast.net [67.177.244.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mellona.thatsmathematics.com (Postfix) with ESMTPSA id 3E7BC1E8A3A; Thu, 14 Dec 2023 23:30:09 +0000 (UTC) Date: Thu, 14 Dec 2023 16:30:07 -0700 (MST) From: Nate Eldredge To: Thomas Rodgers cc: Jonathan Wakely , Jonathan Wakely , gcc-patches , libstdc++ Subject: Re: [PATCH 1/2] libstdc++: Atomic wait/notify ABI stabilization In-Reply-To: Message-ID: <021f0c1a-3e37-9e3f-bb2b-09b57aca0144@thatsmathematics.com> References: <88357210-2f36-4711-1b2b-0b4185810e7c@thatsmathematics.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-1778804209-1702596609=:162999" X-Spam-Status: No, score=0.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_BARRACUDACENTRAL,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-1778804209-1702596609=:162999 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8BIT On Thu, 14 Dec 2023, Thomas Rodgers wrote: > I need to look at this a bit more (and not on my phone, at lunch). > Ultimately, C++26 expects to add predicate waits and returning a > ‘tri-state’ result isn’t something that’s been considered or likely to be > approved. Ok, then that seems to fit best with my second suggestion: the predicate should only test the value and do nothing else, and actually trying to decrement the semaphore is left up to the caller _M_acquire(), which must then retry __atomic_wait_address if the compare-exchange fails. -- Nate Eldredge nate@thatsmathematics.com --8323329-1778804209-1702596609=:162999--