From patchwork Mon Mar 16 11:09:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 11440215 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5047613B1 for ; Mon, 16 Mar 2020 11:26:21 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 1FD1620719 for ; Mon, 16 Mar 2020 11:26:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Ws3/mY/v" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1FD1620719 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:37248 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jDnsx-0000Px-RB for patchwork-qemu-devel@patchwork.kernel.org; Mon, 16 Mar 2020 07:26:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42428) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jDndy-0002q0-6b for qemu-devel@nongnu.org; Mon, 16 Mar 2020 07:10:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jDndw-0004lt-Mm for qemu-devel@nongnu.org; Mon, 16 Mar 2020 07:10:50 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:46550 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jDndw-0004iq-Gy for qemu-devel@nongnu.org; Mon, 16 Mar 2020 07:10:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584357048; 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=8jcU/HCwQAmCeBKP7ipq7laiBGMA1+e7a1zl9eXhO+4=; b=Ws3/mY/v8iRWqOe9Y4l6TcL29PRb5IcQaufxbsI+10ovTtdfyCiv/MALwcybEef7cy3NO3 1rVlGwhGBHfriS3of2VVUU3acj9+pJf6uoXPfq1+otyJQMnwisL2GQ2kn5ijHb1GzWD/oh WdOUvtYrxzy7/p6RjQCZWw3pHA3Khv4= 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-160-Cdc2hFlXOZCg45S3M_k8Uw-1; Mon, 16 Mar 2020 07:10:46 -0400 X-MC-Unique: Cdc2hFlXOZCg45S3M_k8Uw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AD4D6101FC6A; Mon, 16 Mar 2020 11:10:45 +0000 (UTC) Received: from localhost (unknown [10.36.119.36]) by smtp.corp.redhat.com (Postfix) with ESMTP id EA5E71036B54; Mon, 16 Mar 2020 11:10:15 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: [PATCH v2 1/2] lockable: add lock guards Date: Mon, 16 Mar 2020 11:09:56 +0000 Message-Id: <20200316110957.449700-2-stefanha@redhat.com> In-Reply-To: <20200316110957.449700-1-stefanha@redhat.com> References: <20200316110957.449700-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 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: Paolo Bonzini , =?utf-8?q?Alex_Benn=C3=A9e?= , Markus Armbruster , Stefan Hajnoczi , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" This patch introduces two lock guard macros that automatically unlock a lock object (QemuMutex and others): void f(void) { QEMU_LOCK_GUARD(&mutex); if (!may_fail()) { return; /* automatically unlocks mutex */ } ... } and: WITH_QEMU_LOCK_GUARD(&mutex) { if (!may_fail()) { return; /* automatically unlocks mutex */ } } /* automatically unlocks mutex here */ ... Convert qemu-timer.c functions that benefit from these macros as an example. Manual qemu_mutex_lock/unlock() callers are left unmodified in cases where clarity would not improve by switching to the macros. Many other QemuMutex users remain in the codebase that might benefit from lock guards. Over time they can be converted, if that is desirable. Signed-off-by: Stefan Hajnoczi --- include/qemu/lockable.h | 65 +++++++++++++++++++++++++++++++++++++++++ util/qemu-timer.c | 23 +++++++-------- 2 files changed, 76 insertions(+), 12 deletions(-) diff --git a/include/qemu/lockable.h b/include/qemu/lockable.h index 84ea794bcf..2b52c7c1e5 100644 --- a/include/qemu/lockable.h +++ b/include/qemu/lockable.h @@ -93,4 +93,69 @@ static inline void qemu_lockable_unlock(QemuLockable *x) x->unlock(x->object); } +static inline QemuLockable *qemu_lockable_auto_lock(QemuLockable *x) +{ + qemu_lockable_lock(x); + return x; +} + +static inline void qemu_lockable_auto_unlock(QemuLockable *x) +{ + if (x) { + qemu_lockable_unlock(x); + } +} + +G_DEFINE_AUTOPTR_CLEANUP_FUNC(QemuLockable, qemu_lockable_auto_unlock) + +#define WITH_QEMU_LOCK_GUARD_(x, var) \ + for (g_autoptr(QemuLockable) var = \ + qemu_lockable_auto_lock(QEMU_MAKE_LOCKABLE((x))); \ + var; \ + qemu_lockable_auto_unlock(var), var = NULL) + +/** + * WITH_QEMU_LOCK_GUARD - Lock a lock object for scope + * + * @x: a lock object (currently one of QemuMutex, CoMutex, QemuSpin). + * + * This macro defines a lock scope such that entering the scope takes the lock + * and leaving the scope releases the lock. Return statements are allowed + * within the scope and release the lock. Break and continue statements leave + * the scope early and release the lock. + * + * WITH_QEMU_LOCK_GUARD(&mutex) { + * ... + * if (error) { + * return; <-- mutex is automatically unlocked + * } + * + * if (early_exit) { + * break; <-- leave this scope early + * } + * ... + * } + */ +#define WITH_QEMU_LOCK_GUARD(x) \ + WITH_QEMU_LOCK_GUARD_((x), qemu_lockable_auto##__COUNTER__) + +/** + * QEMU_LOCK_GUARD - Lock an object until the end of the scope + * + * @x: a lock object (currently one of QemuMutex, CoMutex, QemuSpin). + * + * This macro takes a lock until the end of the scope. Return statements + * release the lock. + * + * ... <-- mutex not locked + * QEMU_LOCK_GUARD(&mutex); <-- mutex locked from here onwards + * ... + * if (error) { + * return; <-- mutex is automatically unlocked + * } + */ +#define QEMU_LOCK_GUARD(x) \ + g_autoptr(QemuLockable) qemu_lockable_auto##__COUNTER__ = \ + qemu_lockable_auto_lock(QEMU_MAKE_LOCKABLE((x))) + #endif diff --git a/util/qemu-timer.c b/util/qemu-timer.c index ef52d28d37..d548d3c1ad 100644 --- a/util/qemu-timer.c +++ b/util/qemu-timer.c @@ -25,6 +25,7 @@ #include "qemu/osdep.h" #include "qemu/main-loop.h" #include "qemu/timer.h" +#include "qemu/lockable.h" #include "sysemu/replay.h" #include "sysemu/cpus.h" @@ -186,13 +187,12 @@ bool timerlist_expired(QEMUTimerList *timer_list) return false; } - qemu_mutex_lock(&timer_list->active_timers_lock); - if (!timer_list->active_timers) { - qemu_mutex_unlock(&timer_list->active_timers_lock); - return false; + WITH_QEMU_LOCK_GUARD(&timer_list->active_timers_lock) { + if (!timer_list->active_timers) { + return false; + } + expire_time = timer_list->active_timers->expire_time; } - expire_time = timer_list->active_timers->expire_time; - qemu_mutex_unlock(&timer_list->active_timers_lock); return expire_time <= qemu_clock_get_ns(timer_list->clock->type); } @@ -225,13 +225,12 @@ int64_t timerlist_deadline_ns(QEMUTimerList *timer_list) * value but ->notify_cb() is called when the deadline changes. Therefore * the caller should notice the change and there is no race condition. */ - qemu_mutex_lock(&timer_list->active_timers_lock); - if (!timer_list->active_timers) { - qemu_mutex_unlock(&timer_list->active_timers_lock); - return -1; + WITH_QEMU_LOCK_GUARD(&timer_list->active_timers_lock) { + if (!timer_list->active_timers) { + return -1; + } + expire_time = timer_list->active_timers->expire_time; } - expire_time = timer_list->active_timers->expire_time; - qemu_mutex_unlock(&timer_list->active_timers_lock); delta = expire_time - qemu_clock_get_ns(timer_list->clock->type); From patchwork Mon Mar 16 11:09:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 11440277 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1D86113B1 for ; Mon, 16 Mar 2020 12:00:08 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id E44E420658 for ; Mon, 16 Mar 2020 12:00:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="UtaDc8IG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E44E420658 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:37568 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jDoPe-0004GN-G2 for patchwork-qemu-devel@patchwork.kernel.org; Mon, 16 Mar 2020 08:00:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42505) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jDne0-0002tb-RR for qemu-devel@nongnu.org; Mon, 16 Mar 2020 07:10:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jDndz-0005Mc-DQ for qemu-devel@nongnu.org; Mon, 16 Mar 2020 07:10:52 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:57672 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jDndz-0005CS-5L for qemu-devel@nongnu.org; Mon, 16 Mar 2020 07:10:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584357050; 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=XgE+vdHZP8+R7ZEnD4oIE/yB0B6AtgFjwBdfiemBG0c=; b=UtaDc8IGZAs9cBWmp2Zy7T2PJ1uU0aNgs+FLllHPlrauveRN0PpDQqBkqx3ZzNbrPXKDfS 7e5n65UpyiUWBbXMoTEcpRKwV6Id+W9ySLRv59jWkqcLcW/ULYoKLQKAii9Ij1VkQjVt83 0Xsa76VrEcQXDSRC4gaZDYfsCoXSvmY= 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-316-I_bLVJ0gPdeQwc2FAwTqeQ-1; Mon, 16 Mar 2020 07:10:48 -0400 X-MC-Unique: I_bLVJ0gPdeQwc2FAwTqeQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0699518FE881; Mon, 16 Mar 2020 11:10:48 +0000 (UTC) Received: from localhost (unknown [10.36.119.36]) by smtp.corp.redhat.com (Postfix) with ESMTP id DA733610DC; Mon, 16 Mar 2020 11:10:46 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: [PATCH v2 2/2] lockable: add QemuRecMutex support Date: Mon, 16 Mar 2020 11:09:57 +0000 Message-Id: <20200316110957.449700-3-stefanha@redhat.com> In-Reply-To: <20200316110957.449700-1-stefanha@redhat.com> References: <20200316110957.449700-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.61 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: Paolo Bonzini , =?utf-8?q?Alex_Benn=C3=A9e?= , Markus Armbruster , Stefan Hajnoczi , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" The polymorphic locking macros don't support QemuRecMutex yet. Add it so that lock guards can be used with QemuRecMutex. Convert TCG plugins functions that benefit from these macros. Manual qemu_rec_mutex_lock/unlock() callers are left unmodified in cases where clarity would not improve by switching to the macros. Signed-off-by: Stefan Hajnoczi --- include/qemu/lockable.h | 2 ++ plugins/core.c | 7 +++---- plugins/loader.c | 16 ++++++++-------- 3 files changed, 13 insertions(+), 12 deletions(-) diff --git a/include/qemu/lockable.h b/include/qemu/lockable.h index 2b52c7c1e5..44b3f4be72 100644 --- a/include/qemu/lockable.h +++ b/include/qemu/lockable.h @@ -50,6 +50,7 @@ qemu_make_lockable(void *x, QemuLockable *lockable) #define QEMU_LOCK_FUNC(x) ((QemuLockUnlockFunc *) \ QEMU_GENERIC(x, \ (QemuMutex *, qemu_mutex_lock), \ + (QemuRecMutex *, qemu_rec_mutex_lock), \ (CoMutex *, qemu_co_mutex_lock), \ (QemuSpin *, qemu_spin_lock), \ unknown_lock_type)) @@ -57,6 +58,7 @@ qemu_make_lockable(void *x, QemuLockable *lockable) #define QEMU_UNLOCK_FUNC(x) ((QemuLockUnlockFunc *) \ QEMU_GENERIC(x, \ (QemuMutex *, qemu_mutex_unlock), \ + (QemuRecMutex *, qemu_rec_mutex_unlock), \ (CoMutex *, qemu_co_mutex_unlock), \ (QemuSpin *, qemu_spin_unlock), \ unknown_lock_type)) diff --git a/plugins/core.c b/plugins/core.c index ed863011ba..51bfc94787 100644 --- a/plugins/core.c +++ b/plugins/core.c @@ -15,6 +15,7 @@ #include "qemu/error-report.h" #include "qemu/config-file.h" #include "qapi/error.h" +#include "qemu/lockable.h" #include "qemu/option.h" #include "qemu/rcu_queue.h" #include "qemu/xxhash.h" @@ -150,11 +151,11 @@ do_plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev, { struct qemu_plugin_ctx *ctx; - qemu_rec_mutex_lock(&plugin.lock); + QEMU_LOCK_GUARD(&plugin.lock); ctx = plugin_id_to_ctx_locked(id); /* if the plugin is on its way out, ignore this request */ if (unlikely(ctx->uninstalling)) { - goto out_unlock; + return; } if (func) { struct qemu_plugin_cb *cb = ctx->callbacks[ev]; @@ -178,8 +179,6 @@ do_plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev, } else { plugin_unregister_cb__locked(ctx, ev); } - out_unlock: - qemu_rec_mutex_unlock(&plugin.lock); } void plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev, diff --git a/plugins/loader.c b/plugins/loader.c index 15fc7e5515..685d334e1a 100644 --- a/plugins/loader.c +++ b/plugins/loader.c @@ -19,6 +19,7 @@ #include "qemu/error-report.h" #include "qemu/config-file.h" #include "qapi/error.h" +#include "qemu/lockable.h" #include "qemu/option.h" #include "qemu/rcu_queue.h" #include "qemu/qht.h" @@ -367,15 +368,14 @@ void plugin_reset_uninstall(qemu_plugin_id_t id, struct qemu_plugin_reset_data *data; struct qemu_plugin_ctx *ctx; - qemu_rec_mutex_lock(&plugin.lock); - ctx = plugin_id_to_ctx_locked(id); - if (ctx->uninstalling || (reset && ctx->resetting)) { - qemu_rec_mutex_unlock(&plugin.lock); - return; + WITH_QEMU_LOCK_GUARD(&plugin.lock) { + ctx = plugin_id_to_ctx_locked(id); + if (ctx->uninstalling || (reset && ctx->resetting)) { + return; + } + ctx->resetting = reset; + ctx->uninstalling = !reset; } - ctx->resetting = reset; - ctx->uninstalling = !reset; - qemu_rec_mutex_unlock(&plugin.lock); data = g_new(struct qemu_plugin_reset_data, 1); data->ctx = ctx;