Re: [dpdk-dev] [PATCH 1/3] ring: remove experimental tag for ring reset API

["Kinsella, Ray" <mdr@ashroe.eu>]

On 03/07/2020 19:46, Honnappa Nagarahalli wrote:
> <snip>
> 
>>
>> On 03/07/2020 11:26, Feifei Wang wrote:
>>> Remove the experimental tag for rte_ring_reset API that have been
>>> around for 4 releases.
>>>
>>> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
>>> Reviewed-by: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
>>> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
>>> ---
>>>  lib/librte_ring/rte_ring.h           | 3 ---
>>>  lib/librte_ring/rte_ring_version.map | 4 +---
>>>  2 files changed, 1 insertion(+), 6 deletions(-)
>>>
>>> diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h
>>> index f67141482..7181c33b4 100644
>>> --- a/lib/librte_ring/rte_ring.h
>>> +++ b/lib/librte_ring/rte_ring.h
>>> @@ -663,15 +663,12 @@ rte_ring_dequeue(struct rte_ring *r, void **obj_p)
>>>   *
>>>   * This function flush all the elements in a ring
>>>   *
>>> - * @b EXPERIMENTAL: this API may change without prior notice
>>> - *
>>>   * @warning
>>>   * Make sure the ring is not in use while calling this function.
>>>   *
>>>   * @param r
>>>   *   A pointer to the ring structure.
>>>   */
>>> -__rte_experimental
>>>  void
>>>  rte_ring_reset(struct rte_ring *r);
>>>
>>> diff --git a/lib/librte_ring/rte_ring_version.map
>>> b/lib/librte_ring/rte_ring_version.map
>>> index e88c143cf..aec6f3820 100644
>>> --- a/lib/librte_ring/rte_ring_version.map
>>> +++ b/lib/librte_ring/rte_ring_version.map
>>> @@ -8,6 +8,7 @@ DPDK_20.0 {
>>>  	rte_ring_init;
>>>  	rte_ring_list_dump;
>>>  	rte_ring_lookup;
>>> +	rte_ring_reset;
>>>
>>>  	local: *;
>>>  };
>>> @@ -15,9 +16,6 @@ DPDK_20.0 {
>>>  EXPERIMENTAL {
>>>  	global:
>>>
>>> -	# added in 19.08
>>> -	rte_ring_reset;
>>> -
>>>  	# added in 20.02
>>>  	rte_ring_create_elem;
>>>  	rte_ring_get_memsize_elem;
>>
>> So strictly speaking, rte_ring_reset is part of the DPDK_21 ABI, not the v20.0
>> ABI.
> Thanks Ray for clarifying this.
> 
>>
>> The way to solve is to add it the DPDK_21 ABI in the map file.
>> And then use the VERSION_SYMBOL_EXPERIMENTAL to alias to experimental
>> if necessary.
> Is using VERSION_SYMBOL_EXPERIMENTAL a must? 

Purely at the discretion of the contributor and maintainer. 
If it has been around for a while, applications are using it and changing the symbol will break them.

You may choose to provide the alias or not. 

> The documentation also seems to be vague. It says " The macro is used when a symbol matures to become part of the stable ABI, to provide an alias to experimental for some time". What does 'some time' mean?

"Some time" is a bit vague alright, should be "until the next major ABI version" - I will fix. 

> 
>>
>> https://doc.dpdk.org/guides/contributing/abi_versioning.html#versioning-
>> macros