From: SASADA Koichi <ko1@...>
Date: 2013-05-20T18:39:57+09:00
Subject: [ruby-core:55085] Re: [ruby-trunk - Feature #8426][Open] Implement class hierarchy method caching

(2013/05/20 18:21), Charlie Somerville wrote:
> funny_falcon explained this well. It's significantly faster in this case
> when compared to st_table.

Thanks guys, I understand. Maybe it is used to implement weak reference
from super class to sub classes, right?

>> It will help debugging.
> I think this is a reasonable proposal. I'll add it. 

Thanks.

>> # minor comment: `sa_' prefix is too short :P
> What would you suggest? Ruby already exports symbols with short
> prefixes, eg. st_. 

I prefer `st_' related name. But not strong opinion.

One more:

    if (LIKELY(GET_METHOD_STATE_VERSION() == ci->vmstat &&
        RCLASS_EXT(klass)->seq == ci->seq &&
        klass == ci->klass)) {

should be:

    if (LIKELY(GET_METHOD_STATE_VERSION() == ci->vmstat &&
        klass == ci->klass &&
        RCLASS_EXT(klass)->seq == ci->seq) {

...?
why you use vmstat?

     if (klass == ci->klass &&
         RCLASS_EXT(klass)->seq == ci->seq) {

is not enough?

Ah, you only use for re-def BasicObject, Object and Kernel.

+  if (klass == rb_cBasicObject || klass == rb_cObject || klass ==
rb_mKernel) {
+      INC_METHOD_STATE_VERSION();
+  } else {

Is it huge performance bottleneck? I think branch on inline cache should
be removed.

-- 
// SASADA Koichi at atdot dot net