Hi Richard, On Wed, 2022-03-30 at 22:16 +0200, Richard Weinberger via Xenomai wrote: > Starting with Xenomai 3, RT_MUTEX is based on libcobalt's pthread mutex > implementation. > POSIX requires that pthread_mutex_lock() shall not return EINTR, > this requirement breaks rt_task_unblock() if a RT_TASK blocks on > a RT_MUTEX. >
I can't say much about the alchemy skin. Never used that myself. Have you checked the history if such a change was / could be intentional? CCing Jan... The following comments are more or less implementation details... > To restore the functionality provide a new function, > pthread_mutex_lock_eintr_np(). > It can get interrupted and will return EINTR to the caller. > > Signed-off-by: Richard Weinberger <[email protected]> > --- > include/cobalt/pthread.h | 2 ++ > lib/alchemy/mutex.c | 2 +- > lib/cobalt/mutex.c | 14 ++++++++++++-- > 3 files changed, 15 insertions(+), 3 deletions(-) > > diff --git a/include/cobalt/pthread.h b/include/cobalt/pthread.h > index 3e9bd47053bc..2994c2467219 100644 > --- a/include/cobalt/pthread.h > +++ b/include/cobalt/pthread.h > @@ -62,6 +62,8 @@ COBALT_DECL(int, pthread_mutex_destroy(pthread_mutex_t > *mutex)); > > COBALT_DECL(int, pthread_mutex_lock(pthread_mutex_t *mutex)); > > +COBALT_DECL(int, pthread_mutex_lock_eintr_np(pthread_mutex_t *mutex)); > + COBALT_DECL should only be necessary for functions that live in the libc namespace and that need to be "intercepted" / affected by wrapping at linker level. Your function looks libcobalt specific and as such should probably not live in the pthread_mutex_ namespace and generating the wrappers seems unnecessary. > COBALT_DECL(int, pthread_mutex_timedlock(pthread_mutex_t *mutex, > const struct timespec *to)); > > diff --git a/lib/alchemy/mutex.c b/lib/alchemy/mutex.c > index f8933858647a..bb97395142aa 100644 > --- a/lib/alchemy/mutex.c > +++ b/lib/alchemy/mutex.c > @@ -327,7 +327,7 @@ int rt_mutex_acquire_timed(RT_MUTEX *mutex, > > /* Slow path. */ > if (abs_timeout == NULL) { > - ret = -__RT(pthread_mutex_lock(&mcb->lock)); > + ret = -__RT(pthread_mutex_lock_eintr_np(&mcb->lock)); > goto done; > } > > diff --git a/lib/cobalt/mutex.c b/lib/cobalt/mutex.c > index 73e45a1c4396..2ef02a175c13 100644 > --- a/lib/cobalt/mutex.c > +++ b/lib/cobalt/mutex.c > @@ -314,7 +314,7 @@ COBALT_IMPL(int, pthread_mutex_destroy, (pthread_mutex_t > *mutex)) > * > * @apitags{xthread-only, switch-primary} > */ > -COBALT_IMPL(int, pthread_mutex_lock, (pthread_mutex_t *mutex)) > +static int __pthread_mutex_lock(pthread_mutex_t *mutex, bool want_eintr) > { > struct cobalt_mutex_shadow *_mutex = > &((union cobalt_mutex_union *)mutex)->shadow_mutex; > @@ -373,7 +373,7 @@ slow_path: > > do > ret = XENOMAI_SYSCALL1(sc_cobalt_mutex_lock, _mutex); > - while (ret == -EINTR); > + while (ret == -EINTR && !want_eintr); > > if (ret == 0) > _mutex->lockcnt = 1; > @@ -392,6 +392,16 @@ protect: > goto fast_path; > } > > +COBALT_IMPL(int, pthread_mutex_lock, (pthread_mutex_t *mutex)) > +{ > + return __pthread_mutex_lock(mutex, false); > +} > + > +COBALT_IMPL(int, pthread_mutex_lock_eintr_np, (pthread_mutex_t *mutex)) > +{ > + return __pthread_mutex_lock(mutex, true); > +} Same as above. Looks libcobalt specific and the wrapping part seems unnecessary. > + > /** > * Attempt, during a bounded time, to lock a mutex. > *
