On 30.03.22 22:16, 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.
>
> 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(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));
This won't build for mercury, will it?
Jan
> 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);
> +}
> +
> /**
> * Attempt, during a bounded time, to lock a mutex.
> *
--
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