From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:36649) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QzUjI-0001rW-Bb for qemu-devel@nongnu.org; Fri, 02 Sep 2011 10:28:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QzUjH-0004sg-30 for qemu-devel@nongnu.org; Fri, 02 Sep 2011 10:28:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:24361) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QzUjG-0004sL-Oz for qemu-devel@nongnu.org; Fri, 02 Sep 2011 10:28:23 -0400 Date: Fri, 2 Sep 2011 11:28:18 -0300 From: Luiz Capitulino Message-ID: <20110902112818.13bddde0@doriath> In-Reply-To: <4E5FF20B.5030504@web.de> References: <1314900738-30164-1-git-send-email-lcapitulino@redhat.com> <1314900738-30164-4-git-send-email-lcapitulino@redhat.com> <4E5FCF61.4040404@siemens.com> <20110901153917.112c5428@doriath> <4E5FF20B.5030504@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 3/8] RunState: Add additional states List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: "kwolf@redhat.com" , "amit.shah@redhat.com" , "aliguori@us.ibm.com" , "qemu-devel@nongnu.org" , "armbru@redhat.com" On Thu, 01 Sep 2011 22:58:51 +0200 Jan Kiszka wrote: > On 2011-09-01 20:39, Luiz Capitulino wrote: > > On Thu, 01 Sep 2011 20:30:57 +0200 > > Jan Kiszka wrote: > > > >> On 2011-09-01 20:12, Luiz Capitulino wrote: > >>> Currently, only vm_start() and vm_stop() change the VM state. > >>> That's, the state is only changed when starting or stopping the VM. > >>> > >>> This commit adds the runstate_set() function, which makes it possible > >>> to also do state transitions when the VM is stopped or running. > >>> > >>> Additional states are also added and the current state is stored. > >>> > >>> Signed-off-by: Luiz Capitulino > >>> --- > >>> cpus.c | 1 + > >>> migration.c | 8 +++++++- > >>> sysemu.h | 10 +++++++++- > >>> vl.c | 20 ++++++++++++++++++++ > >>> 4 files changed, 37 insertions(+), 2 deletions(-) > >>> > >> > >> ... > >> > >>> diff --git a/vl.c b/vl.c > >>> index f0b56a4..59f71fc 100644 > >>> --- a/vl.c > >>> +++ b/vl.c > >>> @@ -321,6 +321,22 @@ static int default_driver_check(QemuOpts *opts, void *opaque) > >>> } > >>> > >>> /***********************************************************/ > >>> +/* QEMU state */ > >>> + > >>> +static RunState current_run_state = RSTATE_NO_STATE; > >>> + > >>> +bool runstate_check(RunState state) > >>> +{ > >>> + return current_run_state == state; > >>> +} > >>> + > >>> +void runstate_set(RunState state) > >>> +{ > >>> + assert(state < RSTATE_MAX); > >>> + current_run_state = state; > >> > >> I still think this should check for valid state transitions instead of > >> blindly accepting what the caller passes in. > > > > I thought your comment where more like a future enhancement than > > a request for change. > > I think we want this now to document at a central place which > transitions are valid and which not. State machines without such checks > break sooner or later, subtly. Ok, I'll do it. Do you have any suggestion on the preferred way to document it? Should I use english or try some ascii art? > > > > > What to do if the transition is invalid? abort()? > > Yes. > > Jan >