From patchwork Fri Apr 25 06:58:23 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Yingliang X-Patchwork-Id: 676 Return-Path: X-Original-To: siddhesh@wilcox.dreamhost.com Delivered-To: siddhesh@wilcox.dreamhost.com Received: from homiemail-mx23.g.dreamhost.com (mx2.sub5.homie.mail.dreamhost.com [208.113.200.128]) by wilcox.dreamhost.com (Postfix) with ESMTP id 020283604D1 for ; Fri, 25 Apr 2014 00:00:00 -0700 (PDT) Received: by homiemail-mx23.g.dreamhost.com (Postfix, from userid 14307373) id A9C0B630292A8; Fri, 25 Apr 2014 00:00:00 -0700 (PDT) X-Original-To: glibc@patchwork.siddhesh.in Delivered-To: x14307373@homiemail-mx23.g.dreamhost.com Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by homiemail-mx23.g.dreamhost.com (Postfix) with ESMTPS id 8644963031C5F for ; Fri, 25 Apr 2014 00:00:00 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:message-id:date:from:mime-version:to:cc :subject:content-type:content-transfer-encoding; q=dns; s= default; b=Bnhry7zWyT3N3V0kd4Zqb9ky2fQyPObc7kTD5LviSGKiKdzho7ZJe eJvLer15guseliS0dBf1fVCpuo9FEhbMxOwLdviJCAy0vtB2BSf8QHQU++jl8S5/ sLDc8k0m+zPB/vvzfk8XMTCaPVf5+D0GyQ/iNGEFBPIajC+flIVQ1Q= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:message-id:date:from:mime-version:to:cc :subject:content-type:content-transfer-encoding; s=default; bh=r YGb+WqhjGwv0220rBbapxibJSY=; b=DaudeK4Q+KiWGmI+SvpkK6dHSxTG4u03n Acri5tM8ZYnlomjPeEwpzID2yL96DGzr6rPVeZNJdiYjg311l5ZLVs4eLNF+ZZZj J548VHo4RV8bGprK2EFLp+kymfUU/Pghft35At5YQ5Aub2YuVwcIUhPzK2PN+FJj uYmZe5Mhto= Received: (qmail 23300 invoked by alias); 25 Apr 2014 06:59:58 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 23280 invoked by uid 89); 25 Apr 2014 06:59:57 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, RP_MATCHES_RCVD, SPF_PASS autolearn=ham version=3.3.2 X-Spam-User: qpsmtpd, 2 recipients X-HELO: szxga03-in.huawei.com Message-ID: <535A078F.3050003@huawei.com> Date: Fri, 25 Apr 2014 14:58:23 +0800 From: Yang Yingliang User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: CC: , Subject: shared data protection failed in pthread_cond_timedwait X-CFilter-Loop: Reflected X-DH-Original-To: glibc@patchwork.siddhesh.in Hi, I have 22 threads wait in pthread_cond_timedwait. When they are all woke up, I found there are more than one threads can access shared data in pthread_cond_timedwait. I added print messages as follow code: I tested on Linux arma15el 3.10.37+ #2 SMP Fri Apr 25 11:23:25 CST 2014 armv7l GNU/Linux. Here is the result: start do sub :45, lock:1 0xb6d9a460 end do sub :43, lock:1 0xb6d9a460 start do sub :43, lock:1 0xb6d9e460 end do sub :41, lock:2 0xb6d9e460 start do sub :43, lock:2 0xb6dbe460 //two threads both access the shared data start do sub :41, lock:1 0xb6daa460 end do sub :39, lock:2 0xb6daa460 start do sub :39, lock:2 0xb6de6460 end do sub :37, lock:2 0xb6de6460 start do sub :37, lock:2 0xb6db6460 end do sub :35, lock:2 0xb6db6460 start do sub :35, lock:2 0xb6dc2460 end do sub :33, lock:2 0xb6dc2460 end do sub :37, lock:2 0xb6dbe460 start do sub :33, lock:2 0xb6dc6460 end do sub :31, lock:0 0xb6dc6460 start do sub :31, lock:2 0xb6dae460 end do sub :29, lock:2 0xb6dae460 start do sub :29, lock:2 0xb6db2460 end do sub :27, lock:2 0xb6db2460 start do sub :27, lock:2 0xb6dba460 end do sub :25, lock:2 0xb6dba460 start do sub :25, lock:2 0xb6da2460 end do sub :23, lock:2 0xb6da2460 Is lll_lock (cond->__data.__lock, pshared) failed? pshared is LLL_SHARED. --- libc/nptl/pthread_cond_timedwait.c +++ libc/nptl/pthread_cond_timedwait.c @@ -34,6 +34,7 @@ #else # include #endif +#include /* Cleanup handler, defined in pthread_cond_wait.c. */ extern void __condvar_cleanup (void *arg) @@ -235,7 +239,9 @@ bc_out: +printf("start do sub :%d, lock:%d %p\n", cond->__data.__nwaiters, cond->__data.__lock, pthread_self()); cond->__data.__nwaiters -= 1 << COND_NWAITERS_SHIFT; +printf("end do sub :%d, lock:%d %p\n", cond->__data.__nwaiters, cond->__data.__lock, pthread_self()); /* If pthread_cond_destroy was called on this variable already, notify the pthread_cond_destroy caller all waiters have left