From patchwork Mon Feb 21 08:43:26 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 83786 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 37B1CB7132 for ; Mon, 21 Feb 2011 19:59:54 +1100 (EST) Received: from localhost ([127.0.0.1]:40235 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PrRcV-0000kI-5N for incoming@patchwork.ozlabs.org; Mon, 21 Feb 2011 03:59:51 -0500 Received: from [140.186.70.92] (port=49207 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PrRNA-0004gJ-F9 for qemu-devel@nongnu.org; Mon, 21 Feb 2011 03:44:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PrRN9-0000Kt-3x for qemu-devel@nongnu.org; Mon, 21 Feb 2011 03:44:00 -0500 Received: from mail-wy0-f173.google.com ([74.125.82.173]:61006) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PrRN8-0000I2-Uh for qemu-devel@nongnu.org; Mon, 21 Feb 2011 03:43:59 -0500 Received: by mail-wy0-f173.google.com with SMTP id 29so1150726wyb.4 for ; Mon, 21 Feb 2011 00:43:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:sender:from:to:subject:date:message-id:x-mailer :in-reply-to:references; bh=ey7Po4Acnjm9YxAAEMJtyfNA6n6JSHHSwbAch82ze/4=; b=RtNfsA/2714xidgon0fZwDa4gRJji188OpT/G8uSTWI5BISkCVY0MiSbsPQZHivOwh S3OI+HbXvR+1WdD/6t4kRKXF54I23lQJypFmnhcPdZwZi2naJ8ALAFUGkM60jHj2XURG /e9zlSWbfGFyCk/vYx2ybtg+InfHhyq3mkWmk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:from:to:subject:date:message-id:x-mailer:in-reply-to :references; b=AniK25h3lOieKDNEZ6Ldo48W5D3z4JRNW6Et/4yuvjB0RclJ9wmS7xBvQfZ7g7Y90x FTPJpsezmSepFZbcMAe1u7Xhn1nbPRObDDosk0GzTu57Fqeod/70dUd1y/nrT6QhaBaJ l4MMdMsPR8Og/Tx5819UrwRjNIWLo/uDbnEUw= Received: by 10.216.162.70 with SMTP id x48mr1898890wek.4.1298277838488; Mon, 21 Feb 2011 00:43:58 -0800 (PST) Received: from localhost.localdomain (93-34-149-100.ip50.fastwebnet.it [93.34.149.100]) by mx.google.com with ESMTPS id t5sm1945464wes.9.2011.02.21.00.43.57 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 21 Feb 2011 00:43:57 -0800 (PST) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Mon, 21 Feb 2011 09:43:26 +0100 Message-Id: <1298277820-8817-8-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.7.3.5 In-Reply-To: <1298277820-8817-1-git-send-email-pbonzini@redhat.com> References: <1298277820-8817-1-git-send-email-pbonzini@redhat.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-Received-From: 74.125.82.173 Subject: [Qemu-devel] [PATCH 07/21] add assertions on the owner of a QemuMutex X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org These are already present in the Win32 implementation, add them to the pthread wrappers as well. Signed-off-by: Paolo Bonzini --- qemu-thread-posix.c | 27 +++++++++++++++++++++++++-- qemu-thread-posix.h | 1 + 2 files changed, 26 insertions(+), 2 deletions(-) diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c index 28b3f80..2176f81 100644 --- a/qemu-thread-posix.c +++ b/qemu-thread-posix.c @@ -16,9 +16,12 @@ #include #include #include +#include #include #include "qemu-thread.h" +static pthread_t pthread_null; + static void error_exit(int err, const char *msg) { fprintf(stderr, "qemu: %s: %s\n", msg, strerror(err)); @@ -28,8 +31,13 @@ static void error_exit(int err, const char *msg) void qemu_mutex_init(QemuMutex *mutex) { int err; + pthread_mutexattr_t mutexattr; - err = pthread_mutex_init(&mutex->lock, NULL); + mutex->owner = pthread_null; + pthread_mutexattr_init(&mutexattr); + pthread_mutexattr_settype(&mutexattr, PTHREAD_MUTEX_ERRORCHECK); + err = pthread_mutex_init(&mutex->lock, &mutexattr); + pthread_mutexattr_destroy(&mutexattr); if (err) error_exit(err, __func__); } @@ -48,13 +56,20 @@ void qemu_mutex_lock(QemuMutex *mutex) int err; err = pthread_mutex_lock(&mutex->lock); + mutex->owner = pthread_self(); if (err) error_exit(err, __func__); } int qemu_mutex_trylock(QemuMutex *mutex) { - return pthread_mutex_trylock(&mutex->lock); + int err; + err = pthread_mutex_trylock(&mutex->lock); + if (err == 0) { + mutex->owner = pthread_self(); + } + + return !!err; } static void timespec_add_ms(struct timespec *ts, uint64_t msecs) @@ -85,6 +100,11 @@ void qemu_mutex_unlock(QemuMutex *mutex) { int err; + /* An EDEADLOCK would arrive after we reset the owner. So this + assert is for ease of debugging (it lets you see what is the + actual owner. */ + assert(pthread_equal(mutex->owner, pthread_self())); + mutex->owner = pthread_null; err = pthread_mutex_unlock(&mutex->lock); if (err) error_exit(err, __func__); @@ -130,7 +150,10 @@ void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex) { int err; + assert(pthread_equal(mutex->owner, pthread_self())); + mutex->owner = pthread_null; err = pthread_cond_wait(&cond->cond, &mutex->lock); + mutex->owner = pthread_self(); if (err) error_exit(err, __func__); } diff --git a/qemu-thread-posix.h b/qemu-thread-posix.h index 7af371c..11978db 100644 --- a/qemu-thread-posix.h +++ b/qemu-thread-posix.h @@ -4,6 +4,7 @@ struct QemuMutex { pthread_mutex_t lock; + pthread_t owner; }; struct QemuCond {