From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.droids-corp.org (zoll.droids-corp.org [94.23.50.67]) by dpdk.org (Postfix) with ESMTP id 8DD081B5C5 for ; Tue, 26 Jun 2018 15:21:28 +0200 (CEST) Received: from rsa59-2-82-233-193-189.fbx.proxad.net ([82.233.193.189] helo=droids-corp.org) by mail.droids-corp.org with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1fXnut-0004RZ-AO; Tue, 26 Jun 2018 15:21:57 +0200 Received: by droids-corp.org (sSMTP sendmail emulation); Tue, 26 Jun 2018 15:21:22 +0200 Date: Tue, 26 Jun 2018 15:21:21 +0200 From: Olivier Matz To: Adrien Mazarguil Cc: dev@dpdk.org, Keith Wiles , Jingjing Wu , Thomas Monjalon , Ferruh Yigit , Jim Thompson , Anatoly Burakov Message-ID: <20180626132121.6qm3m3mx2ubkxyn3@platinum> References: <20180417152016.5163-1-adrien.mazarguil@6wind.com> <20180419151155.5680-1-adrien.mazarguil@6wind.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180419151155.5680-1-adrien.mazarguil@6wind.com> User-Agent: NeoMutt/20170113 (1.7.2) Subject: Re: [dpdk-dev] [PATCH v2] cmdline: rework as a wrapper to libedit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 Jun 2018 13:21:28 -0000 Hi Adrien, Better late than never, please find below some comments about your patch. On Thu, Apr 19, 2018 at 05:13:53PM +0200, Adrien Mazarguil wrote: > Disclaimer: this patch must not be confused with the CLI library [1] > (work in progress) that will eventually supersede librte_cmdline itself > with a different API. > > Rather, it modifies librte_cmdline to delegate all the heavy lifting > (terminal and history handling), strips unused features and re-implements > what remains of its public API as a wrapper to the editline library (also > known as libedit) [2], a well-known, BSD-licensed and widely available > library used by many projects which does everything needed and more [3]. > > This approach was chosen because converting librte_cmdline as a wrapper to > a more capable library was easier and faster than addressing its > shortcomings and results in much less code to maintain in DPDK. > > It also provides a drop-in solution for applications that rely on > librte_cmdline. They benefit from greatly improved command line handling > without a meaningful impact on their code base. > > The main motivation behind this patch is testpmd's flow (rte_flow) command, > which requires support for dynamic tokens and very long lines that must be > broken down when displayed. This is not supported by librte_cmdline's > limited terminal handling capabilities, resulting in a rather frustrating > user experience. > > It had to be addressed given the importance of testpmd as one of the > primary tool used by PMD developers. > > This rework results in the following changes: > > - Removed circular buffer management interface for command history > (cmdline_cirbuf.c), command history being handled by libedit. > - Removed raw command-line interpreter (cmdline_rdline.c). > - Removed raw terminal handler (cmdline_vt100.c). > - Removed all test/example code for the above. > - Re-implemented high level interactive and non-interactive command-line > handlers (cmdline.c and cmdline_socket.c) on top of libedit using its > native interface, not its readline compatibility layer. > - Made struct cmdline opaque so that applications relying on librte_cmdline > do not need to include any libedit headers. > - Applications do not need to include cmdline_rdline.h anymore. > - Terminal resizing is now automatically handled. > - New external dependency for applications relying on librte_cmdline. > - Major version bump due to the ABI impact of these changes. > > [1] http://dpdk.org/browse/draft/dpdk-draft-cli/ > [2] http://thrysoee.dk/editline/ > [3] http://netbsd.gw.com/cgi-bin/man-cgi?editline++NetBSD-current > > Signed-off-by: Adrien Mazarguil > Cc: Olivier Matz > Cc: Keith Wiles > Cc: Jingjing Wu > Cc: Thomas Monjalon > Cc: Ferruh Yigit > Cc: Jim Thompson > Cc: Anatoly Burakov > > -- > > v2 changes: > > - Replaced an instance of snprintf() with rte_strlcpy() [5]. > - Rebased patch. > > [5] http://dpdk.org/ml/archives/dev/2018-April/097721.html > > v1 changes: > > No fundamental change since the original RFC [4], except it's been rebased > several times and Meson build support was added in the meantime. Commit log > was also shortened a bit. > > I'm re-sending this because I think it's useful, at least to me (duh). As > the maintainer of rte_flow, I spend most of my time typing flow commands in > testpmd and libedit makes that a pleasant experience. > > Try it out! And don't hesitate to send your acked-by line to get this in > time for 18.05 :) > > [4] http://dpdk.org/ml/archives/dev/2017-November/081605.html Re-saying what I said the first time: I think this is a very good improvement, removing lots of dpdk code that is better implemented in well-known libraries. The compilation with shared libraries fail. Please try for instance: ./devtools/test-build.sh -j4 x86_64-native-linuxapp-clang+shared+debug I suggest to add in lib/librte_cmdline/Makefile: LDLIBS += $(shell pkg-config --libs libedit) I also think something should be added in /doc/guides/linux_gsg/sys_reqs.rst to highlight the new build dependency. I noticed a bad behavior change (in addition to many good ones): ctrl-c now quits the application, and this was not the case before. I often use ctrl-c to delete the line I'm currently editing. Please see at the end a proposition to restore this feature. Finally, the patch removes some functions, so it should be announced with a deprecation notice. [...] > diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c > index 0b442c3a6..6b4d9dbfd 100644 > --- a/app/test-pmd/cmdline.c > +++ b/app/test-pmd/cmdline.c > @@ -48,7 +48,6 @@ > #include > #include > > -#include > #include > #include > #include FYI, after rebase, same hunk is also required in examples/vhost_crypto/main.c [...] > diff --git a/lib/librte_cmdline/cmdline.c b/lib/librte_cmdline/cmdline.c > index 591b78b0f..1c45cd9ff 100644 > --- a/lib/librte_cmdline/cmdline.c > +++ b/lib/librte_cmdline/cmdline.c > @@ -4,79 +4,183 @@ > * All rights reserved. > */ > > +#include > +#include histedit.h would be better after system includes. [...] > @@ -207,48 +317,49 @@ cmdline_poll(struct cmdline *cl) > { > struct pollfd pfd; > int status; > - ssize_t read_status; > - char c; > + int read_status; > + int flags; > > if (!cl) > return -EINVAL; > - else if (cl->rdl.status == RDLINE_EXITED) > + else if (cl->error) > + return RDLINE_ERROR; > + else if (cl->eof) > return RDLINE_EXITED; > > - pfd.fd = cl->s_in; > + pfd.fd = fileno(cl->f_in); > pfd.events = POLLIN; > pfd.revents = 0; > > status = poll(&pfd, 1, 0); > if (status < 0) > - return status; > - else if (status > 0) { > - c = -1; > - read_status = read(cl->s_in, &c, 1); > - if (read_status < 0) > - return read_status; > - > - status = cmdline_in(cl, &c, 1); > - if (status < 0 && cl->rdl.status != RDLINE_EXITED) > - return status; > - } > - > - return cl->rdl.status; > + return RDLINE_ERROR; > + if (!status) > + return RDLINE_RUNNING; > + flags = fcntl(pfd.fd, F_GETFL); > + if (!(flags & O_NONBLOCK)) > + fcntl(pfd.fd, F_SETFL, flags | O_NONBLOCK); We just checked that fd is readable, what is the purpose of adding the O_NONBLOCK flag? > + if (!el_gets(cl->el, &read_status) && read_status == -1) > + cl->error = 1; Either from documentation or libedit code, I don't think it is possible that read_status is set to -1. Am I missing something? > + if (!(flags & O_NONBLOCK)) > + fcntl(pfd.fd, F_SETFL, flags); > + return cl->error ? RDLINE_ERROR : > + cl->eof ? RDLINE_EXITED : > + RDLINE_RUNNING; > } > > void > cmdline_interact(struct cmdline *cl) > { > - char c; > - > if (!cl) > return; > > - c = -1; > - while (1) { > - if (read(cl->s_in, &c, 1) <= 0) > - break; > - if (cmdline_in(cl, &c, 1) < 0) > - break; > + while (!cl->error && !cl->eof) { > + int read_status; > + > + if (el_gets(cl->el, &read_status)) > + continue; > + if (read_status == -1) > + cl->error = 1; Same comment here about read_status. Thanks Olivier