From patchwork Wed Mar 17 12:16:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 1454626 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=ff/BMM0y; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4F0q3x2Vc6z9sTD for ; Wed, 17 Mar 2021 23:20:13 +1100 (AEDT) Received: from localhost ([::1]:54082 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lMV9n-0005O6-94 for incoming@patchwork.ozlabs.org; Wed, 17 Mar 2021 08:20:11 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57258) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMV6a-0002HR-BF; Wed, 17 Mar 2021 08:16:52 -0400 Received: from mail-ej1-x629.google.com ([2a00:1450:4864:20::629]:34835) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lMV6X-0007jm-Gd; Wed, 17 Mar 2021 08:16:51 -0400 Received: by mail-ej1-x629.google.com with SMTP id dx17so2243256ejb.2; Wed, 17 Mar 2021 05:16:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=smfqshe5rWL1zIyiqGH7+GywYlbeI5eZY7MNQuJ+Muk=; b=ff/BMM0yYL2KOKRLefc27F7D0Mg4L1QZPERQBm/dtapY0VMiYI0hn8Xjc+TdPLhRIW 5RiA0p9hSgyS3JJ1B6EGuPlLLlBv6ZmXwf/rb6xPYeFiBRvuAEiNVSjyPXxKk6KTjCxa /iGRTp8+XZxtDsq6fhjmS8tstboUW32x4zK42c/qhZpO8UgifgYhpoLIq5ax4LtnLJHS kCnCmymwPoNG0UKSlONMEe1BBNLHkgNDJA+Ur/katxy7SwgtlbKZera61shzGx7QSaTv RCKeUYA5d3K94S+ooCiMOYhtgTrVaN23zlwcQHHYUPTHKV3qW9DH6fS+BsyOHHrCee0a kCEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=smfqshe5rWL1zIyiqGH7+GywYlbeI5eZY7MNQuJ+Muk=; b=JtJxirP36pG8I8MLqgsfMz2tplblMdQU4Hbe2VkITvT2MOikSOTaHpfZLgZa94MNkS dlnjEAkPsmSpIHJiraewnY1kjc57oB/eJJLMeog1jsWDIHiKcl4fvGITmk9FJEYfaRoA bYFUplU0uopAcySQLn0G2JKEzR/BveFCAS2urdhwL/DodE1Zrz8oPEEuESgU6i0XBo4Z HJYeTalFNXT8Nrm/PYikD7h4/+IlZSG4TxZ67RowCUQ6ABqF3aqq0Qtt6X/7ug6Nst0R MGbIP2JdPQ1f+S7WR30r8zpikExDd4ODsbEP9GBox0tf2gJgiuMqIwKikCYzDWUXZEm+ CSKQ== X-Gm-Message-State: AOAM533ywveV2+xvK6A+LIw+U7d8JstS/1HchdbsLu4++F0g4K1icgRE 0q0FKIx0tmHQ92XlmDBywdrfE0xKoIw= X-Google-Smtp-Source: ABdhPJy7aglDZLedtVIG91Ey87ZuCH5kokcUgj7oB25TmAXtsyFhd6gCrPrhsSg6xP8oq0USxWW8mA== X-Received: by 2002:a17:906:5611:: with SMTP id f17mr35491731ejq.208.1615983407836; Wed, 17 Mar 2021 05:16:47 -0700 (PDT) Received: from avogadro.lan ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id gq25sm11520996ejb.85.2021.03.17.05.16.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Mar 2021 05:16:47 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PATCH 6/6] test-coroutine: Add rwlock downgrade test Date: Wed, 17 Mar 2021 13:16:41 +0100 Message-Id: <20210317121641.215714-7-pbonzini@redhat.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210317121641.215714-1-pbonzini@redhat.com> References: <20210317121641.215714-1-pbonzini@redhat.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::629; envelope-from=paolo.bonzini@gmail.com; helo=mail-ej1-x629.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=0.25, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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: david.edmondson@oracle.com, kwolf@redhat.com, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 failed: (c3_done) Bail out! ERROR:../tests/test-coroutine.c:369:test_co_rwlock_downgrade: assertion failed: (c3_done) ...as a result of the c3 coroutine failing to run to completion. Signed-off-by: David Edmondson Message-Id: <20210309144015.557477-5-david.edmondson@oracle.com> Signed-off-by: Paolo Bonzini --- 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); } +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 = 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 = true; +} + +static void coroutine_fn rwlock_rdlock(void *opaque) +{ + qemu_co_rwlock_rdlock(&rwlock); + + qemu_co_rwlock_unlock(&rwlock); + *(bool *)opaque = true; +} + +static void coroutine_fn rwlock_wrlock(void *opaque) +{ + qemu_co_rwlock_wrlock(&rwlock); + + qemu_co_rwlock_unlock(&rwlock); + *(bool *)opaque = 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 = false; + bool c2_done = false; + bool c3_done = false; + bool c4_done = false; + Coroutine *c1, *c2, *c3, *c4; + + qemu_co_rwlock_init(&rwlock); + + c1 = qemu_coroutine_create(rwlock_rdlock_yield, &c1_done); + c2 = qemu_coroutine_create(rwlock_wrlock_downgrade, &c2_done); + c3 = qemu_coroutine_create(rwlock_rdlock, &c3_done); + c4 = 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_downgrade); if (g_test_perf()) { g_test_add_func("/perf/lifecycle", perf_lifecycle); g_test_add_func("/perf/nesting", perf_nesting);