From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4B8D07D7.4040108@domain.hid> Date: Tue, 02 Mar 2010 13:43:03 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <4B8D0359.4070504@domain.hid> <4B8D0466.7040403@domain.hid> <4B8D0542.1020904@domain.hid> <4B8D05B3.1020202@domain.hid> In-Reply-To: <4B8D05B3.1020202@domain.hid> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-core] [Xenomai-git] Jan Kiszka : Native: Fix return code of in-kernel rt_cond_wait[_until] List-Id: Xenomai life and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gilles Chanteperdrix Cc: Xenomai core Gilles Chanteperdrix wrote: > Gilles Chanteperdrix wrote: >> Jan Kiszka wrote: >>> Gilles Chanteperdrix wrote: >>>> GIT version control wrote: >>>>> Module: xenomai-jki >>>>> Branch: for-upstream >>>>> Commit: f1dfda551b6997f74141986759932e2723a9f024 >>>>> URL: http://git.xenomai.org/?p=xenomai-jki.git;a=commit;h=f1dfda551b6997f74141986759932e2723a9f024 >>>>> >>>>> Author: Jan Kiszka >>>>> Date: Tue Mar 2 13:17:35 2010 +0100 >>>>> >>>>> Native: Fix return code of in-kernel rt_cond_wait[_until] >>>>> >>>>> In rt_cond_wait_inner, do not let rt_cond_wait_epilogue overwrite the >>>>> primary error code of rt_cond_wait_prologue. This restores the in-kernel >>>>> semantics of rt_cond_wait[_until] that were valid before 97323b3287. >>>>> >>>>> Signed-off-by: Jan Kiszka >>>>> >>>>> --- >>>>> >>>>> ksrc/skins/native/cond.c | 8 ++++---- >>>>> 1 files changed, 4 insertions(+), 4 deletions(-) >>>>> >>>>> diff --git a/ksrc/skins/native/cond.c b/ksrc/skins/native/cond.c >>>>> index 10727d1..2dc0069 100644 >>>>> --- a/ksrc/skins/native/cond.c >>>>> +++ b/ksrc/skins/native/cond.c >>>>> @@ -472,10 +472,10 @@ static int rt_cond_wait_inner(RT_COND *cond, RT_MUTEX *mutex, >>>>> err = rt_cond_wait_prologue(cond, mutex, &lockcnt, >>>>> timeout_mode, timeout); >>>>> >>>>> - if(!err || err == -ETIMEDOUT || err == -EINTR) >>>>> - do { >>>>> - err = rt_cond_wait_epilogue(mutex, lockcnt); >>>>> - } while (err == -EINTR); >>>>> + if (!err || err == -ETIMEDOUT || err == -EINTR) { >>>>> + while (rt_cond_wait_epilogue(mutex, lockcnt) == -EINTR) >>>>> + ; /* empty */ >>>>> + } >>>> Not ok. If rt_cond_wait_epilogue returns an error other than -EINTR, we >>>> want this error to be returned. >>> As I said: This is what we used to do in 2.4 (and early 2.5-rc), and due >>> to the absence of spec on this topic, I would vote for restoring old >>> behavior. >> if rt_cond_wait_epilogue returns an error other than -EINTR, there is an >> error to be signaled, so, it should be returned to the user, not 0 or >> -ETIMEDOUT which would let the user think that he got the mutex back, >> whereas the mutex is probably not properly locked. > > And if prologue returned -EINTR, and epilogue ran successfully, we do > not want to return -EINTR to the user either. We surely want as the cond_wait did NOT succeed in that case. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux