From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 3331F383EC72 for ; Fri, 10 Jun 2022 10:45:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3331F383EC72 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1654857916; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=uGM3DvlO7RTRlqynVEqlcFFRSRAqysrKd8SB2QUmPt4=; b=J+mxkwBtkBIiiEyNtM6C8hhZf/sJqwH162Jbb53PM+/EyBjbgwzvsprF2VvqR4tc7aPmLo nFZv229reLKUchOWN/9vY+EnOzChjQLFS+NTSR0KmUPPSpUKRDRIgtisd5uu0WOOXaELIM STxT665MuFLhlw+XqXOtrjxL9AYvRMs= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-139-xA5rfmY5Mx2fANMZC3xnIw-1; Fri, 10 Jun 2022 06:45:15 -0400 X-MC-Unique: xA5rfmY5Mx2fANMZC3xnIw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5329D811E7A for ; Fri, 10 Jun 2022 10:45:15 +0000 (UTC) Received: from calimero.vinschen.de (unknown [10.39.192.34]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2504C2166B26 for ; Fri, 10 Jun 2022 10:45:15 +0000 (UTC) Received: by calimero.vinschen.de (Postfix, from userid 500) id 6073CA80970; Fri, 10 Jun 2022 12:45:13 +0200 (CEST) Date: Fri, 10 Jun 2022 12:45:13 +0200 From: Corinna Vinschen To: newlib@sourceware.org Subject: Re: [PATCH v2] Use global stdio streams for all configurations Message-ID: Reply-To: newlib@sourceware.org Mail-Followup-To: newlib@sourceware.org References: <20220608094357.12224-1-sebastian.huber@embedded-brains.de> MIME-Version: 1.0 In-Reply-To: <20220608094357.12224-1-sebastian.huber@embedded-brains.de> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vinschen@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-Spam-Status: No, score=-5.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: newlib@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Newlib mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Jun 2022 10:45:22 -0000 On Jun 8 11:43, Sebastian Huber wrote: > The _REENT_GLOBAL_STDIO_STREAMS was introduced by commit > 668a4c8722090fffd10869dbb15b879651c1370d in 2017. Since then it was enabled by > default for RTEMS. Recently, the option was enabled for Cygwin which > previously used an alternative implementation to use global stdio streams. > > In Newlib, the stdio streams are defined to thread-specific pointers > _reent::_stdin, _reent::_stdout and _reent::_stderr. If the option is disabled > (the default for most systems), then these pointers are initialized to > thread-specific FILE objects which use file descriptors 0, 1, and 2, > respectively. There are at least three problems with this: > > (1) The thread-specific FILE objects are closed by _reclaim_reent(). This > leads to problems with language run-time libraries that provide wrappers to > the C/POSIX stdio streams (for example C++ and Ada), since they use the > thread-specific FILE objects of the initialization thread. In case the > initialization thread is deleted, then they use freed memory. > > (2) Since thread-specific FILE objects are used with a common output device via > file descriptors 0, 1 and 2, the locking at FILE object level cannot ensure > atomicity of the output, e.g. a call to printf(). > > (3) There are resource managment issues, see: > > https://sourceware.org/pipermail/newlib/2022/019558.html > > https://bugs.linaro.org/show_bug.cgi?id=5841 > > This patch enables the _REENT_GLOBAL_STDIO_STREAMS behaviour for all Newlib > configurations and removes the option. This removes a couple of #ifdef blocks. > --- > v2: > > * Add missing ';' to _REENT_INIT_PTR_ZEROED(). > > * Rebase to Newlib master. > > newlib/README | 6 -- > newlib/configure.ac | 10 +-- > newlib/libc/include/sys/config.h | 7 -- > newlib/libc/include/sys/reent.h | 118 +++----------------------- > newlib/libc/reent/impure.c | 6 -- > newlib/libc/reent/reent.c | 20 ----- > newlib/libc/stdio/fcloseall.c | 4 - > newlib/libc/stdio/findfp.c | 53 +----------- > newlib/libc/stdio/local.h | 17 ---- > winsup/cygwin/include/cygwin/config.h | 1 - > 10 files changed, 14 insertions(+), 228 deletions(-) LGTM together with your "Fix __fp_lock_all() and __fp_unlock_all()" patch. Thx, Corinna