DKIM-Filter: OpenDKIM Filter v2.11.0 delorie.com 44U90Y6E2029181 Authentication-Results: delorie.com; dkim=pass (1024-bit key, unprotected) header.d=cygwin.com header.i=@cygwin.com header.a=rsa-sha256 header.s=default header.b=qdN8j+VK X-Recipient: archive-cygwin@delorie.com DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2D86F3858417 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com; s=default; t=1717059632; bh=SZUVBHZBLg6uXAOXo7XspCMfKP34imXO2BSljxO+v0E=; h=Date:Subject:To:References:In-Reply-To:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=qdN8j+VKrZbhneqXoOvbCR3zA06wSGo2zUskWGXVYv77D06JUiNHjdy0hbN1mmKsG hCXbdTiObjFVA+wJbY5OSEe3MqOzX/Ak1rzRwSeSPczdaG4PU9lcBNyCEmQW2boszQ QNdUr2i9/pqaLyIwo8lnWkm2vAIP1oRC6J5VHeMY= X-Original-To: cygwin@cygwin.com Delivered-To: cygwin@cygwin.com DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org DD35C3858D20 ARC-Filter: OpenARC Filter v1.0.0 sourceware.org DD35C3858D20 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1717059605; cv=none; b=VFEY31gZwQVAoG7EB9mwbxzLIcpfPaUkzxOsbYYPIYXo29HB7I/3pIanApngdu7u/jHWGYI5fZ47fgBX8i4y2chALuTrrakpNKdAEmDAuWaDs8GeZZN58e6T0gxXiBwSHhF1/lZH0UXypIjj5m1VgKFkY2pqZZ1rm0zx1iGLA6A= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1717059605; c=relaxed/simple; bh=jNJBE5eWSN3ipV2YYtdp44bpWLifXHppAVFGOer5Alk=; h=DKIM-Signature:Message-ID:Date:MIME-Version:Subject:To:From; b=gn4HJgUQmQZ7J5u6irOraIl/0Yr9eLxrRYNwNO/BCZrq9uVwv4i3cGWt64n8oA/t4sdy//1kAdx+HEhrts02Ydrd+HqViliRedcqZJsQJQDgCPYbY32zMnYaaT7f4TdNlhWUQxKjffcTqGAONUcarPBS7hHiOBrxDxUwnAQM7rM= ARC-Authentication-Results: i=1; server2.sourceware.org X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717059602; x=1717664402; h=content-transfer-encoding:in-reply-to:from:content-language :references:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=tMvfmLdWOQKCpGVNyPVII3zRjx352A6NdRs944krOjQ=; b=fw3BstOoizqXa8kT7SwPE8+25MATgWRL0UpJ+obE2dTf5tOETUInfi99ivfBb/4cT7 qC4rwJX4E5f4hK6e9ykk1xTyOizAX9a0jxK5cdlplg3QYmYaVP24BvGFqTy9XVB2IeE3 EndqwWb1HEEbmIrz25Ee7IxILsa1WcbU3LjJ1A0QDuMd/JtRsv6+8Ih/z6MVAfd1+Ivq aOJJ6MtXiEyJw7fBT9R3vgytolm5zwHhdK4i4TwmofCCs08iJ+wH+Ra4wn3YerCuHY77 gK8ba/WZXqObGF92lCGHvWs7taNVBA5ueSkIM0UIJgFXGnBTyn369Znsme2hfMGeucs4 kCLw== X-Forwarded-Encrypted: i=1; AJvYcCX87Zvj21YIR/0ImmwbUmb46zW7rELSOvLhCxMmIpnfPP58PuZjkUnCj3BRsiKL+ADwWnxCBFX8T2QWU/kIho6mqQ== X-Gm-Message-State: AOJu0YxH3n3SkA0ixtJL6kUyupgniZwMNM0KvdEBtIRCFrw93rklAmLQ 6tSLs4MqEHUYfbwFrHuK4On/RUokCS7xhhLK+lZ8vUyPbUgM9H35 X-Google-Smtp-Source: AGHT+IG+rx6NOTkJrlkBD1WbrIL/OXsurQk81IwmiZWqiC5b10FZtm+u6V4deXMsph2HjUi/CTCjjg== X-Received: by 2002:a5d:58fa:0:b0:354:fb1a:25f5 with SMTP id ffacd0b85a97d-35dc00c9a4cmr1108247f8f.52.1717059602327; Thu, 30 May 2024 02:00:02 -0700 (PDT) Message-ID: <3eeb5e89-b225-4d68-b290-94dd3b9a3594@gmail.com> Date: Thu, 30 May 2024 10:59:59 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] Cygwin: pthread: Fix a race issue introduced by the commit 2c5433e5da82 To: Bruno Haible , Takashi Yano , cygwin@cygwin.com References: <20240530050538.53724-1-takashi.yano@nifty.ne.jp> <0126a98a-3bdc-4303-a0d2-09f4c7009392@gmail.com> <1721092.SVj2RUA3Z2@nimes> Content-Language: en-GB In-Reply-To: <1721092.SVj2RUA3Z2@nimes> X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, KAM_NUMSUBJECT, RCVD_IN_DNSWL_NONE, 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 X-BeenThere: cygwin@cygwin.com X-Mailman-Version: 2.1.30 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Noel Grandin via Cygwin Reply-To: Noel Grandin Content-Type: text/plain; charset="utf-8"; Format="flowed" Errors-To: cygwin-bounces+archive-cygwin=delorie.com@cygwin.com Sender: "Cygwin" Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by delorie.com id 44U90Y6E2029181 On 5/30/2024 10:47 AM, Bruno Haible wrote: > > SRW locks are spin-locks. Since they are only pointer-sized, > ReleaseSRWLockExclusive cannot notify other threads — unlike CRITICAL_SECTION. > Therefore, AcquireSRWLockExclusive must busy-loop when the lock is already > held. > No, they only spin briefly, before calling into the OS to sleep - see the article about their internals here: https://learn.microsoft.com/en-us/archive/msdn-magazine/2012/november/windows-with-c-the-evolution-of-synchronization-in-windows-and-c#slim-readerwriter-lock Alternatively, Windows already has an API for init-once i.e. https://learn.microsoft.com/en-us/windows/win32/sync/one-time-initialization -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple