naming consistency for kernel object initializer macros

[pabigot]

What is the policy for naming the initializer value macro for objects defined in kernel.h?

I see the following being used:

Object	KObj	Recommended	Deprecated
FIFO	no	Z_*	K_*
FUTEX_DATA*	yes	Z_*
LIFO	no	_K_*	K_*
MBOX	no	_K_*	K_*
MEM_SLAB	yes	_K_*	K_*
MSGQ	yes	_K_*	K_*
MUTEX	yes	_K_*	K_*
PIPE	yes	_K_*	K_*
POLL_EVENT	no	K_*
POLL_SIGNAL	yes	K_*
QUEUE	yes	_K_*	K_*
SEM	yes	Z_*	K_*
STACK	yes	_K_*	K_*
TIMER	yes	Z_*	K_*
WORK	no	Z_*	K_*

[*] FUTEX_DATA is the initialized object, FUTEX is the kernel object.

The selection between Z_*, _K_*, and K_* has no pattern I can immediately discern. This makes it difficult to figure out how to initialize a kernel object at compile-time (must go to the header and see which spelling is used for the type).

[andrewboie]

K_ is public.
Z_ is not.
_K_ needs to be changed to Z_, whoever did the naming conversion a couple years ago to rename variables with prefixed underscores to Z_ didn't finish the job.

[pabigot]

@andrewboie Thanks. I thought it might be that, but was surprised that I can't statically initialize semaphores and timers without using a non-public API.

[nashif]

but was surprised that I can't statically initialize semaphores and timers without using a non-public API.

You should be using K_SEM_DEFINE for that?

[pabigot]

You should be using K_SEM_DEFINE for that?

Thanks for the clue; I see what happened. This all started because I wanted to statically define a k_delayed_work instance, but there is no K_DELAYED_WORK_DEFINE() or K_DELAYED_WORK_INITIALIZER, so I have to do it with:

static k_delayed_work work = {
    .work = Z_WORK_INITIALIZER(work_handler),
};

Also I'd planned to have a semaphore inside another structure, for which the *_DEFINE() macros don't work.

Probably there should be an issue to finish the conversion of _K_* to Z_*, and backfill any missing *_DEFINE() macros, but that's not this one. Questions answered; thanks.