Refactor `vm_lookup_cc` to allow lock-free lookups in `RClass.cc_tbl`

In multi-ractor mode, the `cc_tbl` mutations use the RCU pattern,
which allow lock-less reads.

Based on the assumption that invalidations and misses should be
increasingly rare as the process ages, locking on modification
isn't a big concern.

1 files changed, 0 insertions, 35 deletions

diff --git a/imemo.c b/imemo.c
index a7d0b84c56..7298d78d65 100644
--- a/imemo.c
+++ b/imemo.c
@@ -515,41 +515,6 @@ rb_free_const_table(struct rb_id_table *tbl)
     rb_id_table_free(tbl);
 }
 
-// alive: if false, target pointers can be freed already.
-static void
-vm_ccs_free(struct rb_class_cc_entries *ccs, int alive, VALUE klass)
-{
-    if (ccs->entries) {
-        for (int i=0; i<ccs->len; i++) {
-            const struct rb_callcache *cc = ccs->entries[i].cc;
-            if (!alive) {
-                // ccs can be free'ed.
-                if (rb_gc_pointer_to_heap_p((VALUE)cc) &&
-                    !rb_objspace_garbage_object_p((VALUE)cc) &&
-                    IMEMO_TYPE_P(cc, imemo_callcache) &&
-                    cc->klass == klass) {
-                    // OK. maybe target cc.
-                }
-                else {
-                    continue;
-                }
-            }
-
-            VM_ASSERT(!vm_cc_super_p(cc) && !vm_cc_refinement_p(cc));
-            vm_cc_invalidate(cc);
-        }
-        ruby_xfree(ccs->entries);
-    }
-    ruby_xfree(ccs);
-}
-
-void
-rb_vm_ccs_free(struct rb_class_cc_entries *ccs)
-{
-    RB_DEBUG_COUNTER_INC(ccs_free);
-    vm_ccs_free(ccs, true, Qundef);
-}
-
 static inline void
 imemo_fields_free(struct rb_fields *fields)
 {