context_pmc3 branch and backward compatibility.

[Allison Randal]

Vasily Chekalkin wrote:
> Hello.
> 
> In context_pmc3 branch I converted direct using of Parrot_Context* to 
> Context PMC. Unfortunately it will break any HLL which depend on current 
> Parrot_Context struct.
> 
> So, question is "Does deprecation policy cover this situation and we 
> have to live with refcounted Context which causes memory leaks, 
> segfaults and eat kittens for breakfast until next deprecation cycle"?

Yes, it means it has to wait. Which gives you plenty of time to add a 
deprecation notice, and think about a sane migration strategy for the 
users. And, to do performance testing, to see if the change will help or 
hurt us.

> BTW, there is only 2 tests failing in parrot's testsuite. And after 
> tweaking rakudo's sources it passing make spectest.

And plenty of time to fix those two failing tests.

> Ah. And yes, branch is ready for code review.

And plenty of time for code review, and any fixes based on the code review.

It's possible that you might merge some of the changes into trunk before 
  2.0, if you can split out a subset that preserves the existing 
behavior. (I haven't looked at the code yet, so can't say for sure if 
that would work here.)

Allison