From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dmta1001.nifty.com (mta-snd01010.nifty.com [106.153.227.42]) by sourceware.org (Postfix) with ESMTPS id 744AB3858C01 for ; Thu, 24 Aug 2023 03:31:33 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 744AB3858C01 Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=nifty.ne.jp Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=nifty.ne.jp Received: from HP-Z230 by dmta1001.nifty.com with ESMTP id <20230824033131235.TRZQ.19115.HP-Z230@nifty.com> for ; Thu, 24 Aug 2023 12:31:31 +0900 Date: Thu, 24 Aug 2023 12:31:31 +0900 From: Takashi Yano To: cygwin@cygwin.com Subject: Re: scp stalls on uploading in cygwin 3.5 current master. Message-Id: <20230824123131.390b4471915c963425c77608@nifty.ne.jp> In-Reply-To: <20230824060502.c4798062cb19d4d35a5633ae@nifty.ne.jp> References: <20230824060502.c4798062cb19d4d35a5633ae@nifty.ne.jp> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.30; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-11.8 required=5.0 tests=BAYES_00,GIT_PATCH_0,KAM_DMARC_STATUS,NICE_REPLY_A,SPF_HELO_PASS,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Thu, 24 Aug 2023 06:05:02 +0900 Takashi Yano wrote: > Hi Corinna, > > After the commit dedbbd74d0a8, "scp file server:." stalls. > I confirmed this when the "server" is a Linux machine. > The problem does not occur if it is reverted. > > Could you please have a look? > > commit dedbbd74d0a8f3b7dfae6188321703a47bb8a2b3 > Author: Corinna Vinschen > Date: Tue Aug 1 14:22:55 2023 +0200 > > Cygwin: select: workaround FD_WRITE network event handling > > The FD_WRITE event is a false friend. It indicates ready to write > even if the next send fails with WSAEWOULDBLOCK. *After* the fact, > FD_WRITE will be cleared until sending is again possible, but that > is too late for a select/write loop. > > Workaround that by using the WinSock select function when peeking > at a socket and FD_WRITE gets indicated. WinSock select fortunately > indicates writability correctly. > > Fixes: 70e476d27be8 ("(peek_socket): Use event handling for peeking socket.") > Signed-off-by: Corinna Vinschen I'm not sure why at all, however, the following patch seems to solve the issue. diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc index 7b9473849..de5794c9f 100644 --- a/winsup/cygwin/select.cc +++ b/winsup/cygwin/select.cc @@ -1790,7 +1790,7 @@ peek_socket (select_record *me, bool) if (events & FD_WRITE) { wfd_set w = { 1, { fh->get_socket () } }; - TIMEVAL t = { 0 }; + TIMEVAL t = { .tv_sec = 0, .tv_usec = 1 }; if (_win32_select (0, NULL, &w, NULL, &t) == 0) events &= ~FD_WRITE; -- Takashi Yano