From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4B8BC277.4010108@domain.hid> Date: Mon, 01 Mar 2010 14:34:47 +0100 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <4B881E9D.1050101@domain.hid> <4B88203F.2020907@domain.hid> <4B8903E1.3020805@domain.hid> <4B8B7540.609@domain.hid> <4B8B84BC.90300@domain.hid> <4B8B971D.5080807@domain.hid> <4B8B98F5.10602@domain.hid> <4B8BA361.1040807@domain.hid> In-Reply-To: <4B8BA361.1040807@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-core] [Xenomai-git] Jan Kiszka : RTDM+POSIX: Avoid leaking binding objects on errors List-Id: Xenomai life and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Xenomai core Jan Kiszka wrote: > Gilles Chanteperdrix wrote: >> Jan Kiszka wrote: >>> Gilles Chanteperdrix wrote: >>>> Jan Kiszka wrote: >>>>> Jan Kiszka wrote: >>>>>> Jan Kiszka wrote: >>>>>>> Gilles Chanteperdrix wrote: >>>>>>>> GIT version control wrote: >>>>>>>>> diff --git a/ksrc/skins/posix/mq.c b/ksrc/skins/posix/mq.c >>>>>>>>> index 11f47c0..a896031 100644 >>>>>>>>> --- a/ksrc/skins/posix/mq.c >>>>>>>>> +++ b/ksrc/skins/posix/mq.c >>>>>>>>> @@ -1283,6 +1283,7 @@ int pse51_mq_select_bind(mqd_t fd, struct xnselector *selector, >>>>>>>>> return 0; >>>>>>>>> >>>>>>>>> unlock_and_error: >>>>>>>>> + xnfree(binding): >>>>>>>>> xnlock_put_irqrestore(&nklock, s); >>>>>>>>> return err; >>>>>>>>> } >>>>>>>> Ok. Will pull. But I really need to fix that. >>>>>>>> >>>>>>> Ack - now that I see it myself. >>>>>>> >>>>>> I fixed this in my branch and added another patch to transform EIDRM >>>>>> into EBADF when selecting a (half-)deleted RTDM device. Please merge. >>>>>> >>>>> Wait! When the sync object behind some file descriptor is deleted but >>>>> the descriptor itself is still existing, we rather have to return that >>>>> fd signaled from select() instead of letting the call fail. I beed to >>>>> look into this again. >>>> It looks to me like a transitory state, we can wait for the sync object >>>> to be deleted to have the fd destructor signaled. It should not be long. >>> That's not an issue of waiting for this. See e.g. TCP: peer closes >>> connection -> internal sync objects will be destroyed (to make >>> read/write fail). But the fd will remain valid until the local side >>> closes it as well. >> It looks to me like this is going to complicate things a lot, and will >> be a source of regressions. Why can we not have sync objects be >> destroyed when the fd is really destroyed and use a status bit of some >> kind to signal read/write that the fd was closed by peer? > > It is way easier and more consistent to unblock reader and writers via > destroying the sync object than to signal it and add tests for specific > states to detect that. Keep in mind that this pattern is in use even > without select support. Diverging from it just to add select awareness > to some driver would be a step back. Ok. As you wish. But in that case, please provide a unit test case which we can run on all architectures to validate your modifications. We will not put this test case in xenomai repository but will create a repository for test cases later on. -- Gilles.