From nobody Tue Feb 10 16:44:04 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1650353521551334.40582195506465; Tue, 19 Apr 2022 00:32:01 -0700 (PDT) Received: from localhost ([::1]:34146 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ngiLA-0007rd-CV for importer@patchew.org; Tue, 19 Apr 2022 03:32:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33554) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nggmH-0001FT-Go for qemu-devel@nongnu.org; Tue, 19 Apr 2022 01:51:59 -0400 Received: from mail-wr1-x435.google.com ([2a00:1450:4864:20::435]:46606) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nggmF-0004Wd-7J for qemu-devel@nongnu.org; Tue, 19 Apr 2022 01:51:53 -0400 Received: by mail-wr1-x435.google.com with SMTP id i20so20892202wrb.13 for ; Mon, 18 Apr 2022 22:51:50 -0700 (PDT) Received: from avogadro.lan ([2001:b07:6468:f312:e3ec:5559:7c5c:1928]) by smtp.gmail.com with ESMTPSA id bg8-20020a05600c3c8800b0038e4c5967besm15763510wmb.3.2022.04.18.22.51.49 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Apr 2022 22:51:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:from:to:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=8NtQvGNLH0RJY6f1LX0AvyNBK6+G9tQlWq49FJBFkgQ=; b=Xd/dEqlDSat/wlf2f/E9HkvczgfFiXvVRF8cdJEdACaYpob+ZMZjKo2cIspDNdrPwW ro4ETOuhzq4xOjGd3mwt6EIeOUfehQtJ52d6nyeUDct0saCz7AR8EhRAANN5njmPB60C mqNQ8HIqpve12l4aPm46plDHp2zWOFEdOSbqq3XKoAvF8yYU12kLHHoX8JE9PGGzTdGL 6pXD02i94zUSb3UEL4tABVf8FpHiLOiC0yuBl1s+ePJHyN28J9m1edejqabnXuDqL1X0 SckZkCq5ghydHTfZnXvrGf3poFRbcn2V0uwiLKb4vpXEcVhy7uZx4KAL99Rstl1Mm6ZD /L7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:from:to:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=8NtQvGNLH0RJY6f1LX0AvyNBK6+G9tQlWq49FJBFkgQ=; b=wIiPYNfMWsyaYfcCtnc6g6mXZrM8DFP1qEhhONreVhWwuLvSK6d5tGLYcmuC0U+wYE aKdXH7RsL4BUZT6UiZ4wHak+cQU+yOhrXHHk0BnOBJ3vMxzMa5YrT81EV5vLFmtwSIXx LV0x7u4pv6vtbqXmCUNlgDnLahiPLyLcETylEsx+KtsPqEbgV5M4FZDeyqA3r60OiD9t paMAuM6Az9i182gYQvZ1BnV8Xd+OliE4gy1lBjXBvLeIkaz6wtFGlouQ0Js4tWt+lIwK FPFeZd+2nIWNHMy04GNOrLKweOf7RD6NUvDHKjyqatF7QRgBS5XiZp6ys4vc7i6QycYt 0CsA== X-Gm-Message-State: AOAM533R3Cq8GGonyXad61BxSQTGqT3LGNLMkcJqjQW9hdI0Bch+KFxT +WK0Nm8vG8mM+bTS+/d0T/KkQWOGyC0ypg== X-Google-Smtp-Source: ABdhPJx+pjX3Lc5yv4pW/fHnAci8J+wiRTOCNPIYq6rV2OeU/x9fjjO9zT5eaQpl1ca/qWkl4NKapw== X-Received: by 2002:a05:6000:1883:b0:205:c0cb:33c6 with SMTP id a3-20020a056000188300b00205c0cb33c6mr10808834wri.39.1650347509987; Mon, 18 Apr 2022 22:51:49 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 43/53] thread-posix: optimize qemu_sem_timedwait with zero timeout Date: Tue, 19 Apr 2022 07:50:59 +0200 Message-Id: <20220419055109.142788-44-pbonzini@redhat.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220419055109.142788-1-pbonzini@redhat.com> References: <20220419055109.142788-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a00:1450:4864:20::435; envelope-from=paolo.bonzini@gmail.com; helo=mail-wr1-x435.google.com X-Spam_score_int: -14 X-Spam_score: -1.5 X-Spam_bar: - X-Spam_report: (-1.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.249, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1650353523671100001 Content-Type: text/plain; charset="utf-8" In this case there is no need to call pthread_cond_timedwait; the function is just a trywait and waiting on the condition variable would always time out. Signed-off-by: Paolo Bonzini --- util/qemu-thread-posix.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c index 8505d8c60f..ac1d56e673 100644 --- a/util/qemu-thread-posix.c +++ b/util/qemu-thread-posix.c @@ -284,8 +284,12 @@ int qemu_sem_timedwait(QemuSemaphore *sem, int ms) compute_abs_deadline(&ts, ms); qemu_mutex_lock(&sem->mutex); while (sem->count =3D=3D 0) { - rc =3D qemu_cond_timedwait_ts(&sem->cond, &sem->mutex, &ts, - __FILE__, __LINE__); + if (ms =3D=3D 0) { + rc =3D false; + } else { + rc =3D qemu_cond_timedwait_ts(&sem->cond, &sem->mutex, &ts, + __FILE__, __LINE__); + } if (!rc) { /* timeout */ break; } --=20 2.35.1