Introduce disposable call-cache.

This patch contains several ideas:

(1) Disposable inline method cache (IMC) for race-free inline method cache
    * Making call-cache (CC) as a RVALUE (GC target object) and allocate new
      CC on cache miss.
    * This technique allows race-free access from parallel processing
      elements like RCU.
(2) Introduce per-Class method cache (pCMC)
    * Instead of fixed-size global method cache (GMC), pCMC allows flexible
      cache size.
    * Caching CCs reduces CC allocation and allow sharing CC's fast-path
      between same call-info (CI) call-sites.
(3) Invalidate an inline method cache by invalidating corresponding method
    entries (MEs)
    * Instead of using class serials, we set "invalidated" flag for method
      entry itself to represent cache invalidation.
    * Compare with using class serials, the impact of method modification
      (add/overwrite/delete) is small.
    * Updating class serials invalidate all method caches of the class and
      sub-classes.
    * Proposed approach only invalidate the method cache of only one ME.

See [Feature #16614] for more details.

1 files changed, 1 insertions, 0 deletions

diff --git a/ext/objspace/objspace.c b/ext/objspace/objspace.c
index 38d3d2fcff..dc1a0cb08f 100644
--- a/ext/objspace/objspace.c
+++ b/ext/objspace/objspace.c
@@ -638,6 +638,7 @@ count_imemo_objects(int argc, VALUE *argv, VALUE self)
         imemo_type_ids[9] = rb_intern("imemo_ast");
         imemo_type_ids[10] = rb_intern("imemo_parser_strterm");
         imemo_type_ids[11] = rb_intern("imemo_callinfo");
+        imemo_type_ids[12] = rb_intern("imemo_callcache");
     }
 
     rb_objspace_each_objects(count_imemo_objects_i, (void *)hash);