global call-cache cache table for rb_funcall*

rb_funcall* (rb_funcall(), rb_funcallv(), ...) functions invokes
Ruby's method with given receiver. Ruby 2.7 introduced inline method
cache with static memory area. However, Ruby 3.0 reimplemented the
method cache data structures and the inline cache was removed.

Without inline cache, rb_funcall* searched methods everytime.
Most of cases per-Class Method Cache (pCMC) will be helped but
pCMC requires VM-wide locking and it hurts performance on
multi-Ractor execution, especially all Ractors calls methods
with rb_funcall*.

This patch introduced Global Call-Cache Cache Table (gccct) for
rb_funcall*. Call-Cache was introduced from Ruby 3.0 to manage
method cache entry atomically and gccct enables method-caching
without VM-wide locking. This table solves the performance issue
on multi-ractor execution.
[Bug #17497]

Ruby-level method invocation does not use gccct because it has
inline-method-cache and the table size is limited. Basically
rb_funcall* is not used frequently, so 1023 entries can be enough.
We will revisit the table size if it is not enough.

1 files changed, 12 insertions, 0 deletions

diff --git a/vm.c b/vm.c
index 5beb6d0df4..2899433182 100644
--- a/vm.c
+++ b/vm.c
@@ -2588,6 +2588,18 @@ rb_vm_mark(void *ptr)
 	rb_gc_mark_values(RUBY_NSIG, vm->trap_list.cmd);
 
         rb_id_table_foreach_values(vm->negative_cme_table, vm_mark_negative_cme, NULL);
+        for (i=0; i<VM_GLOBAL_CC_CACHE_TABLE_SIZE; i++) {
+            const struct rb_callcache *cc = vm->global_cc_cache_table[i];
+
+            if (cc != NULL) {
+                if (!vm_cc_invalidated_p(cc)) {
+                    rb_gc_mark((VALUE)cc);
+                }
+                else {
+                    vm->global_cc_cache_table[i] = NULL;
+                }
+            }
+        }
 
         mjit_mark();
     }