From nobody Tue Apr 15 02:15:18 2025 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 ARC-Seal: i=1; a=rsa-sha256; t=1617184761; cv=none; d=zohomail.com; s=zohoarc; b=fz0ux/RK2gKRR1bPVQIQuDNWZyaA8BjX4vzXiazXzW2s9BL0Kqu+nw/miQdN4/7USp5ouXQdL+32Tk+t6/4ON0dnlXytFlgP55ESQCRqnCoDBj2cB+KKHr2TA20vvUSP9ZItnlr3NeVZQdlm1/IC9/gCaBgnYTTCNPDeDvZkQZw= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1617184761; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=wckQYKVlGLePyac3Ud9XANvFrgZCkQVjzf9UPTUYLHk=; b=BCzKHWoJU5ElwZilQzSP6rZWHzREUFD5SLqo+NOOFxWOTQxXqnAcJGX4H+rItbWTAn+YgxcmOOMQxjVyxujqucKi52y3CDHX0hFIPLZETfv1BjeDH7eOYmou/TZAyDELUG+XSL8HNvHJv8Yn8MsABQJdpAjFnQJM2LwQ0zD1Bhc= ARC-Authentication-Results: i=1; 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 header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 161718476196155.069633637013794; Wed, 31 Mar 2021 02:59:21 -0700 (PDT) Received: from localhost ([::1]:45410 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lRXdA-00089l-TJ for importer@patchew.org; Wed, 31 Mar 2021 05:59:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51708) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lRXVw-0008Tg-0f for qemu-devel@nongnu.org; Wed, 31 Mar 2021 05:51:52 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:27588) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lRXVu-0001Ot-7f for qemu-devel@nongnu.org; Wed, 31 Mar 2021 05:51:51 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-104-WdlnYraKMISURIwIxb2UXg-1; Wed, 31 Mar 2021 05:51:47 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 07BF98018AC; Wed, 31 Mar 2021 09:51:46 +0000 (UTC) Received: from localhost (ovpn-115-85.ams2.redhat.com [10.36.115.85]) by smtp.corp.redhat.com (Postfix) with ESMTP id A254B4F3C6; Wed, 31 Mar 2021 09:51:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617184309; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wckQYKVlGLePyac3Ud9XANvFrgZCkQVjzf9UPTUYLHk=; b=BSyY8CLJQZXhJgcpENkgvtx62EzGMstiqVOnXMT0bNfUrPSPqPAas96qMmXdZd3qDfZzGI 7k2cFADLELJ34fO4KR9qzq4uqvuZ2nUYUIdfEqnupjhE0hoFAZT9N8sFLnPV0xzkmvApmr YXcsUHk1e6MZyiF9NIWmpZXHG6y6Kw4= X-MC-Unique: WdlnYraKMISURIwIxb2UXg-1 From: Stefan Hajnoczi To: Peter Maydell , qemu-devel@nongnu.org Subject: [PULL for-6.0 6/6] test-coroutine: Add rwlock downgrade test Date: Wed, 31 Mar 2021 10:50:59 +0100 Message-Id: <20210331095059.303996-7-stefanha@redhat.com> In-Reply-To: <20210331095059.303996-1-stefanha@redhat.com> References: <20210331095059.303996-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=stefanha@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com 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=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, MIME_BASE64_TEXT=1.741, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, Juan Quintela , David Edmondson , Stefan Weil , "Michael S. Tsirkin" , "Dr. David Alan Gilbert" , Max Reitz , John Snow , Stefan Hajnoczi , Paolo Bonzini , Eduardo Habkost Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" From: David Edmondson Test that downgrading an rwlock does not result in a failure to schedule coroutines queued on the rwlock. The diagram associated with test_co_rwlock_downgrade() describes the intended behaviour, but what was observed previously corresponds to: | c1 | c2 | c3 | c4 | |--------+------------+------------+----------| | rdlock | | | | | yield | | | | | | wrlock | | | | | | | | | | | rdlock | | | | | | | | | | | wrlock | | | | | | | unlock | | | | | yield | | | | | | | | | | | downgrade | | | | | ... | | | | | unlock | | | | | | | | | | | | | This results in a failure... ERROR:../tests/test-coroutine.c:369:test_co_rwlock_downgrade: assertion fai= led: (c3_done) Bail out! ERROR:../tests/test-coroutine.c:369:test_co_rwlock_downgrade: ass= ertion failed: (c3_done) ...as a result of the c3 coroutine failing to run to completion. Signed-off-by: David Edmondson Signed-off-by: Paolo Bonzini Message-id: 20210325112941.365238-7-pbonzini@redhat.com Message-Id: <20210309144015.557477-5-david.edmondson@oracle.com> Signed-off-by: Paolo Bonzini Signed-off-by: Stefan Hajnoczi --- tests/unit/test-coroutine.c | 99 +++++++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) diff --git a/tests/unit/test-coroutine.c b/tests/unit/test-coroutine.c index 6e6f51d480..aa77a3bcb3 100644 --- a/tests/unit/test-coroutine.c +++ b/tests/unit/test-coroutine.c @@ -325,6 +325,104 @@ static void test_co_rwlock_upgrade(void) g_assert(c2_done); } =20 +static void coroutine_fn rwlock_rdlock_yield(void *opaque) +{ + qemu_co_rwlock_rdlock(&rwlock); + qemu_coroutine_yield(); + + qemu_co_rwlock_unlock(&rwlock); + qemu_coroutine_yield(); + + *(bool *)opaque =3D true; +} + +static void coroutine_fn rwlock_wrlock_downgrade(void *opaque) +{ + qemu_co_rwlock_wrlock(&rwlock); + + qemu_co_rwlock_downgrade(&rwlock); + qemu_co_rwlock_unlock(&rwlock); + *(bool *)opaque =3D true; +} + +static void coroutine_fn rwlock_rdlock(void *opaque) +{ + qemu_co_rwlock_rdlock(&rwlock); + + qemu_co_rwlock_unlock(&rwlock); + *(bool *)opaque =3D true; +} + +static void coroutine_fn rwlock_wrlock(void *opaque) +{ + qemu_co_rwlock_wrlock(&rwlock); + + qemu_co_rwlock_unlock(&rwlock); + *(bool *)opaque =3D true; +} + +/* + * Check that downgrading a reader-writer lock does not cause a hang. + * + * Four coroutines are used to produce a situation where there are + * both reader and writer hopefuls waiting to acquire an rwlock that + * is held by a reader. + * + * The correct sequence of operations we aim to provoke can be + * represented as: + * + * | c1 | c2 | c3 | c4 | + * |--------+------------+------------+------------| + * | rdlock | | | | + * | yield | | | | + * | | wrlock | | | + * | | | | | + * | | | rdlock | | + * | | | | | + * | | | | wrlock | + * | | | | | + * | unlock | | | | + * | yield | | | | + * | | | | | + * | | downgrade | | | + * | | | | | + * | | | unlock | | + * | | ... | | | + * | | unlock | | | + * | | | | | + * | | | | unlock | + */ +static void test_co_rwlock_downgrade(void) +{ + bool c1_done =3D false; + bool c2_done =3D false; + bool c3_done =3D false; + bool c4_done =3D false; + Coroutine *c1, *c2, *c3, *c4; + + qemu_co_rwlock_init(&rwlock); + + c1 =3D qemu_coroutine_create(rwlock_rdlock_yield, &c1_done); + c2 =3D qemu_coroutine_create(rwlock_wrlock_downgrade, &c2_done); + c3 =3D qemu_coroutine_create(rwlock_rdlock, &c3_done); + c4 =3D qemu_coroutine_create(rwlock_wrlock, &c4_done); + + qemu_coroutine_enter(c1); + qemu_coroutine_enter(c2); + qemu_coroutine_enter(c3); + qemu_coroutine_enter(c4); + + qemu_coroutine_enter(c1); + + g_assert(c2_done); + g_assert(c3_done); + g_assert(c4_done); + + qemu_coroutine_enter(c1); + + g_assert(c1_done); +} + /* * Check that creation, enter, and return work */ @@ -563,6 +661,7 @@ int main(int argc, char **argv) g_test_add_func("/locking/co-mutex", test_co_mutex); g_test_add_func("/locking/co-mutex/lockable", test_co_mutex_lockable); g_test_add_func("/locking/co-rwlock/upgrade", test_co_rwlock_upgrade); + g_test_add_func("/locking/co-rwlock/downgrade", test_co_rwlock_downgra= de); if (g_test_perf()) { g_test_add_func("/perf/lifecycle", perf_lifecycle); g_test_add_func("/perf/nesting", perf_nesting); --=20 2.30.2