Re: [PATCH 06/18] libmultipath: use shared_ptr for checker classes

On Tue, May 05, 2026 at 05:43:20PM +0200, Martin Wilck wrote:
> Utilize the share_ptr code for tracking the refcount of checker classes.
> 
> Signed-off-by: Martin Wilck <[email protected]>
> ---
>  libmultipath/checkers.c | 98 +++++++++--------------------------------
>  libmultipath/checkers.h |  2 -
>  2 files changed, 20 insertions(+), 80 deletions(-)
> 
> diff --git a/libmultipath/checkers.c b/libmultipath/checkers.c
> index 8f18ca6..a3b9cc8 100644
> --- a/libmultipath/checkers.c
> +++ b/libmultipath/checkers.c
[...]
> @@ -163,8 +143,7 @@ static struct checker_class *add_checker_class(const char *name)
>  		goto out;
>  
>  	c->mp_init = (int (*)(struct checker *)) dlsym(c->handle, "libcheck_mp_init");
> -	c->reset = (void (*)(void)) dlsym(c->handle, "libcheck_reset");
> -	c->thread = (void *(*)(void*)) dlsym(c->handle, "libcheck_thread");
> +	c->reset = (void (*)(void))dlsym(c->handle, "libcheck_reset");

Nitpick. Dropped a space here.

>  	c->pending = (int (*)(struct checker *)) dlsym(c->handle, "libcheck_pending");
>  	c->need_wait = (bool (*)(struct checker *)) dlsym(c->handle, "libcheck_need_wait");
>  	/* These 5 functions can be NULL. call dlerror() to clear out any
[...]
> @@ -371,43 +350,6 @@ bad_id:
>  	return generic_msg[CHECKER_MSGID_NONE];
>  }

Removing the checker thread stuff is more of a cleanup from d1ebd977. It
should probably either be it's own cleanup patch, or it should at least
get mentioned in the commit message.
  
> -static void checker_cleanup_thread(void *arg)
> -{
> -	struct checker_class *cls = arg;
> -
> -	free_checker_class(cls);
> -	rcu_unregister_thread();
> -}
> -
> -static void *checker_thread_entry(void *arg)
> -{
> -	struct checker_context *ctx = arg;
> -	void *rv;
> -
> -	rcu_register_thread();
> -	pthread_cleanup_push(checker_cleanup_thread, ctx->cls);
> -	rv = ctx->cls->thread(ctx);
> -	pthread_cleanup_pop(1);
> -	return rv;
> -}
> -

Also, start_checker_thread() is stil declared in libmultipath/checkers.h,
along with a comment.

-Ben

> -int start_checker_thread(pthread_t *thread, const pthread_attr_t *attr,
> -			 struct checker_context *ctx)
> -{
> -	int rv;
> -
> -	assert(ctx && ctx->cls && ctx->cls->thread);
> -	/* Take a ref here, lest the class be freed before the thread starts */
> -	(void)checker_class_ref(ctx->cls);
> -	rv = pthread_create(thread, attr, checker_thread_entry, ctx);
> -	if (rv != 0) {
> -		condlog(1, "failed to start checker thread for %s: %m",
> -			ctx->cls->name);
> -		checker_class_unref(ctx->cls);
> -	}
> -	return rv;
> -}
> -
>  void checker_clear_message (struct checker *c)
>  {
>  	if (!c)