Gilles Chanteperdrix wrote: > Jan Kiszka wrote: >> Gilles Chanteperdrix wrote: >>> Jan Kiszka wrote: >>>> Gilles Chanteperdrix wrote: >>>>> Ok for returning -EINTR, it is documented. Kernel-space is not so >>>>> different from user-space, rt_task_unblock could wake-up a kernel-space >>>>> task blocked in a call to rt_cond_wait. >>>>> >>>>> However, if the epilogue returns an error, we must return it. >>>>> >>>> OK for this. Pushed an update, but I also modified it further to avoid >>>> returning without the mutex lock unless that one is also failing. Maybe >>>> in-kernel POSIX requires the same fix, will check. >>> Still not OK. You should reacquire the mutex only if the error is 0, >>> -ETIMEDOUT or -EINTR. With any other error, we do not know if we can >>> call the epilogue safely. >> We _must_ reacquire the mutex - but, granted, we actually have to take >> care of invalid cond objects. Lot's of bugs... > > No. If the error is another error than 0, -ETIMEDOUT, or -EINTR, it > means that the error was detected prior to freeing the mutex. So, we do > not have to re-acquire the mutex. Quoting POSIX: > > "Except in the case of [ETIMEDOUT], all these error checks shall act as > if they were performed immediately at the beginning of processing for > the function and shall cause an error return, in effect, prior to > modifying the state of the mutex specified by mutex or the condition > variable specified by cond." > > POSIX does not talk about -EINTR, because it states that in this case, > we should return 0 to the application.
OK, but EIDRM was missing in your list. Will adjust both patches. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux _______________________________________________ Xenomai-core mailing list Xenomai-core@gna.org https://mail.gna.org/listinfo/xenomai-core
