From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <vdavydov.dev@gmail.com>
Date: Sun, 9 Dec 2018 14:16:37 +0300
From: Vladimir Davydov <vdavydov.dev@gmail.com>
Subject: Re: [tarantool-patches] Re: [PATCH 1/1] netbox: fix wait_connected
 ignorance
Message-ID: <20181209111637.5imhtm7q5zsdi4hh@esperanza>
References: <c20a920cf9fd4294ab5ac062c4e1a95746419ba2.1544022329.git.v.shpilevoy@tarantool.org>
 <20181206174619.aw6ege2sm72yleao@esperanza>
 <76987bec-c41f-4bf7-30ad-8835357fb9d5@tarantool.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <76987bec-c41f-4bf7-30ad-8835357fb9d5@tarantool.org>
To: Vladislav Shpilevoy <v.shpilevoy@tarantool.org>
Cc: tarantool-patches@freelists.org
List-ID: <tarantool-patches.dev.tarantool.org>

On Fri, Dec 07, 2018 at 01:45:16AM +0300, Vladislav Shpilevoy wrote:
> On 06/12/2018 20:46, Vladimir Davydov wrote:
> > On Wed, Dec 05, 2018 at 06:06:39PM +0300, Vladislav Shpilevoy wrote:
> > > diff --git a/src/box/lua/net_box.lua b/src/box/lua/net_box.lua
> > > index fd6ebf9de..d54b3e7d9 100644
> > > --- a/src/box/lua/net_box.lua
> > > +++ b/src/box/lua/net_box.lua
> > > @@ -419,21 +419,21 @@ local function create_transport(host, port, user, password, callback,
> > >       local function start()
> > >           if state ~= 'initial' then return not is_final_state[state] end
> > > -        if not connection and not callback('reconnect_timeout') then
> > > -            set_state('error', E_NO_CONNECTION)
> > > -            return
> > > -        end
> > >           fiber.create(function()
> > >               local ok, err
> > >               worker_fiber = fiber_self()
> > >               fiber.name(string.format('%s:%s (net.box)', host, port), {truncate=true})
> > > -            -- It is possible, if the first connection attempt had
> > > -            -- been failed, but reconnect timeout is set. In such
> > > -            -- a case the worker must be run, and immediately
> > > -            -- start reconnecting.
> > >               if not connection then
> > > -                set_state('error_reconnect', E_NO_CONNECTION, greeting)
> > > -                goto do_reconnect
> > > +                local tm = callback('fetch_connect_timeout')
> > > +                connection, greeting = establish_connection(host, port, tm)
> > 
> > This code is very similar to the reconnect code below. You probably
> > didn't reuse it for a reason, but still, may be we could do something
> > like this?> diff --git a/src/box/lua/net_box.lua
> > b/src/box/lua/net_box.lua
> > index d54b3e7d..f342889a 100644
> > --- a/src/box/lua/net_box.lua
> > +++ b/src/box/lua/net_box.lua
> > @@ -424,16 +424,7 @@ local function create_transport(host, port, user, password, callback,
> >               worker_fiber = fiber_self()
> >               fiber.name(string.format('%s:%s (net.box)', host, port), {truncate=true})
> >               if not connection then
> > -                local tm = callback('fetch_connect_timeout')
> > -                connection, greeting = establish_connection(host, port, tm)
> > -                if not connection then
> > -                    if not callback('reconnect_timeout') then
> > -                        set_state('error', E_NO_CONNECTION, greeting)
> > -                        return
> > -                    end
> > -                    set_state('error_reconnect', E_NO_CONNECTION, greeting)
> > -                    goto do_reconnect
> > -                end
> > +                goto do_connect
> >               end
> >       ::handle_connection::
> >               ok, err = pcall(protocol_sm)
> > @@ -448,6 +439,7 @@ local function create_transport(host, port, user, password, callback,
> >               local timeout = callback('reconnect_timeout')
> >               while timeout and state == 'error_reconnect' do
> >                   fiber.sleep(timeout)
> > +    ::do_connect::
> >                   timeout = callback('reconnect_timeout')
> >                   if not timeout or state ~= 'error_reconnect' then
> >                       break
> > 
> Yes, we can, but there are a few problems:
> 
> 1. In Lua labels have visibility scope. So to put do_connect inside
> while I need to replace while with another explicit goto.
> 
> 2. In the first attempt to connect I set error as set_state('error')
> instead of set_state('error_reconnect') - it is important, because
> the latter logs an error.
> 
> But nonetheless I've solved these problems. This makes diff 3 lines
> shorter, but I am not sure that such a small shortening is worth
> making code less clear. It is up to you.

Thanks, the new version looks more straighforward to me, actually.
Pushed to 2.1 and 1.10.