New APIs and ts.h vs experimental.h

[Leif Hedstrom <zw...@apache.org>]

Hi all,

This has been discussed a few times, but I don't think we agreed on a 
standard or "best practices". As you all know, we have made a promise 
("contract") to not break APIs or ABIs within major releases. This implies 
that once an API goes into ts/ts.h, we can't change the prototype (we can 
change/fix the implementation though, of course).

We have an experimental API include file, ts/experimental.h, where we have a 
bunch of APIs which has not been considered stable or frozen. I have in the 
past moved a number of APIs from this file to ts/ts.h. There are still quite 
a few APIs in this file, some which I think can be promoted, some which I 
have serious concerns about (such as the second CacheVC API, it's just wrong :).

Here's the question / thought: When we add new APIs to the core, should they 
go into ts/ts.h or ts/experimental.h ? Both has pros and cons, as usual, the 
strength of ts/experimental.h is that it allows us to modify prototypes of 
new APIs without breaking the guaranteed API / ABI contract that we have for 
ts/ts.h.

What do you all think?

-- Leif

Re: New APIs and ts.h vs experimental.h

[James Peach <ja...@me.com>]

On Feb 14, 2013, at 9:17 AM, Leif Hedstrom <zw...@apache.org> wrote:

> Hi all,
> 
> This has been discussed a few times, but I don't think we agreed on a standard or "best practices". As you all know, we have made a promise ("contract") to not break APIs or ABIs within major releases. This implies that once an API goes into ts/ts.h, we can't change the prototype (we can change/fix the implementation though, of course).
> 
> We have an experimental API include file, ts/experimental.h, where we have a bunch of APIs which has not been considered stable or frozen. I have in the past moved a number of APIs from this file to ts/ts.h. There are still quite a few APIs in this file, some which I think can be promoted, some which I have serious concerns about (such as the second CacheVC API, it's just wrong :).
> 
> Here's the question / thought: When we add new APIs to the core, should they go into ts/ts.h or ts/experimental.h ? Both has pros and cons, as usual, the strength of ts/experimental.h is that it allows us to modify prototypes of new APIs without breaking the guaranteed API / ABI contract that we have for ts/ts.h.
> 
> What do you all think?

I've been guilty of adding a number of APIs directly to ts.h. As I've stated in the past I would like to see a more formal API review process. I'm fine with pushing APIs through experimental.h, but I don't want that to be a substitute for a formal API review, and I would like to see an additional process for promoting APIs from experimental to stable (eg. we review all experimental APIs at the start of a new release cycle)

J