From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sfi-mx-2.v28.ch3.sourceforge.com ([172.29.28.122] helo=mx.sourceforge.net) by 235xhf1.ch3.sourceforge.com with esmtp (Exim 4.69) (envelope-from ) id 1M61VW-0005Oe-L7 for ltp-list@lists.sourceforge.net; Mon, 18 May 2009 11:59:50 +0000 Received: from e31.co.us.ibm.com ([32.97.110.149]) by 72vjzd1.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.69) id 1M61VS-0006Zn-3a for ltp-list@lists.sourceforge.net; Mon, 18 May 2009 11:59:50 +0000 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e31.co.us.ibm.com (8.13.1/8.13.1) with ESMTP id n4IBtqac024551 for ; Mon, 18 May 2009 05:55:52 -0600 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n4IBxikf078512 for ; Mon, 18 May 2009 05:59:44 -0600 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n4IBxhrZ025362 for ; Mon, 18 May 2009 05:59:43 -0600 From: Subrata Modak In-Reply-To: <20090515134519.GA21654@us.ibm.com> References: <4A0D13F2.8030804@cn.fujitsu.com> <20090515134519.GA21654@us.ibm.com> Date: Mon, 18 May 2009 17:29:38 +0530 Message-Id: <1242647979.5161.12.camel@subratamodak.linux.ibm.com> Mime-Version: 1.0 Subject: Re: [LTP] [PATCH] Synchronization between two processes Reply-To: subrata@linux.vnet.ibm.com List-Id: Linux Test Project General Discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-list-bounces@lists.sourceforge.net To: "Serge E. Hallyn" , Gui Xiaohua Cc: ltp-list@lists.sourceforge.net On Fri, 2009-05-15 at 08:45 -0500, Serge E. Hallyn wrote: > Quoting Gui Xiaohua (guixh@cn.fujitsu.com): > > The child-process wait SIGUSR1 which would be sended by parent-process, > > if the child-process execute sigtimedwait() after parent-process send > > the signal, it would never receive the SIGUSR1 from parent-process. > > I cann't make sure the SIGUSR1 be sended after child-process execute > > sigtimedwait() with 100 percent, and i try my best. > > Well, in theory I suppose this could happen, but you'd have to have > a pretty bad scheduler if the parent can do a strcmp(buf, "c:go") > between the pipe read and signal send, while the child goes straight > from pipe write to sigtimedwait. > > Have you seen this signal be missed? If not, then I'd rather assume > things are reasonable. If you have seen this happen, then why not > instead set up a SIGUSR1 handler in the child before doing the pipe > write, then just sleep for 3 seconds instead of doing sigtimedwait? Thanks Serge. Gui, Are you planning any further patch(s) for this ? Regards-- Subrata > > > Signed-off-by: Gui Xiaohua > > --- testcases/kernel/containers/pidns/pidns12-old.c 2009-05-14 17:00:20.000000000 +0800 > > +++ testcases/kernel/containers/pidns/pidns12.c 2009-05-15 15:15:22.000000000 +0800 > > @@ -109,7 +109,7 @@ int child_fn(void *arg) > > } > > > > /* Set timeout for sigtimedwait */ > > - timeout.tv_sec = 3; > > + timeout.tv_sec = 10; > > timeout.tv_nsec = 0; > > > > /* Set mask to wait for SIGUSR1 signal */ > > @@ -182,6 +182,9 @@ int main(int argc, char *argv[]) > > cleanup(); > > } > > > > + /*Try best to make sure the SIGUSR1 be sended after child-process execute sigtimedwait*/ > > + sleep(5); > > + > > /* Send SIGUSR1 to container init */ > > if (kill(cpid, SIGUSR1) == -1) { > > tst_resm(TBROK, "parent: kill() failed(%s).", strerror(errno)); > > > > > > ------------------------------------------------------------------------------ > > Crystal Reports - New Free Runtime and 30 Day Trial > > Check out the new simplified licensing option that enables > > unlimited royalty-free distribution of the report engine > > for externally facing server and web deployment. > > http://p.sf.net/sfu/businessobjects > > _______________________________________________ > > Ltp-list mailing list > > Ltp-list@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/ltp-list > > ------------------------------------------------------------------------------ > Crystal Reports - New Free Runtime and 30 Day Trial > Check out the new simplified licensing option that enables > unlimited royalty-free distribution of the report engine > for externally facing server and web deployment. > http://p.sf.net/sfu/businessobjects > _______________________________________________ > Ltp-list mailing list > Ltp-list@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/ltp-list ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Ltp-list mailing list Ltp-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ltp-list