* class.c (class_alloc): remove mc_tbl

* gc.c (obj_free): ditto

* internal.h (struct rb_classext_struct): ditto

* method.h (rb_method_entry): remove ent param

* vm_method.c: restore the global method cache. Per class cache tables
  turned out to be far too slow.

  [ruby-core:57289] [Bug #8930]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43027 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,18 @@
+Tue Sep 24 14:01:00 2013  Charlie Somerville  <charliesome@ruby-lang.org>
+
+	* class.c (class_alloc): remove mc_tbl
+
+	* gc.c (obj_free): ditto
+
+	* internal.h (struct rb_classext_struct): ditto
+
+	* method.h (rb_method_entry): remove ent param
+
+	* vm_method.c: restore the global method cache. Per class cache tables
+	  turned out to be far too slow.
+
+	  [ruby-core:57289] [Bug #8930]
+
 Tue Sep 24 12:51:07 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/win32/lib/win32/registry.rb (Win32::Registry::API): need

class.c

@@ -165,7 +165,6 @@ class_alloc(VALUE flags, VALUE klass)
     RCLASS_EXT(obj)->parent_subclasses = NULL;
     RCLASS_EXT(obj)->module_subclasses = NULL;
     RCLASS_EXT(obj)->seq = rb_next_class_sequence();
-    RCLASS_EXT(obj)->mc_tbl = NULL;
 
     RCLASS_REFINED_CLASS(obj) = Qnil;
     RCLASS_EXT(obj)->allocator = 0;

gc.c

@@ -1261,10 +1261,6 @@ obj_free(rb_objspace_t *objspace, VALUE obj)
 	    }
 	    RCLASS_EXT(obj)->subclasses = NULL;
 	}
-	if (RCLASS_EXT(obj)->mc_tbl) {
-	    rb_free_mc_table(RCLASS_EXT(obj)->mc_tbl);
-	    RCLASS_EXT(obj)->mc_tbl = NULL;
-	}
 	rb_class_remove_from_module_subclasses(obj);
 	rb_class_remove_from_super_subclasses(obj);
 	if (RANY(obj)->as.klass.ptr)

internal.h

@@ -266,7 +266,6 @@ struct rb_classext_struct {
     VALUE super;
     struct st_table *iv_tbl;
     struct st_table *const_tbl;
-    struct st_table *mc_tbl;
     rb_subclass_entry_t *subclasses;
     rb_subclass_entry_t **parent_subclasses;
     /**

method.h

@@ -122,7 +122,7 @@ rb_method_entry_t *rb_method_entry_with_refinements(VALUE klass, ID id,
 rb_method_entry_t *rb_method_entry_without_refinements(VALUE klass, ID id,
 						       VALUE *defined_class_ptr);
 
-rb_method_entry_t *rb_method_entry_get_without_cache(VALUE klass, ID id, VALUE *define_class_ptr, method_cache_entry_t *ent);
+rb_method_entry_t *rb_method_entry_get_without_cache(VALUE klass, ID id, VALUE *define_class_ptr);
 rb_method_entry_t *rb_method_entry_set(VALUE klass, ID mid, const rb_method_entry_t *, rb_method_flag_t noex);
 
 int rb_method_entry_arity(const rb_method_entry_t *me);

vm_method.c

@@ -2,6 +2,10 @@
  * This file is included by vm.c
  */
 
+#define GLOBAL_METHOD_CACHE_SIZE 0x800
+#define GLOBAL_METHOD_CACHE_MASK 0x7ff
+#define GLOBAL_METHOD_CACHE_KEY(c,m) ((((c)>>3)^(m))&GLOBAL_METHOD_CACHE_MASK)
+#define GLOBAL_METHOD_CACHE(c,m) (global_method_cache + GLOBAL_METHOD_CACHE_KEY(c,m))
 #include "method.h"
 
 #define NOEX_NOREDEF 0
@@ -20,6 +24,15 @@ static void rb_vm_check_redefinition_opt_method(const rb_method_entry_t *me, VAL
 #define singleton_undefined idSingleton_method_undefined
 #define attached            id__attached__
 
+struct cache_entry {
+    vm_state_version_t vm_state;
+    vm_state_version_t seq;
+    ID mid;
+    rb_method_entry_t* me;
+    VALUE defined_class;
+};
+
+static struct cache_entry global_method_cache[GLOBAL_METHOD_CACHE_SIZE];
 #define ruby_running (GET_VM()->running)
 /* int ruby_running = 0; */
 
@@ -520,26 +533,25 @@ rb_method_entry_at(VALUE klass, ID id)
  */
 rb_method_entry_t *
 rb_method_entry_get_without_cache(VALUE klass, ID id,
-				  VALUE *defined_class_ptr,
-				  method_cache_entry_t *ent)
+				  VALUE *defined_class_ptr)
 {
     VALUE defined_class;
     rb_method_entry_t *me = search_method(klass, id, &defined_class);
 
     if (ruby_running) {
+	struct cache_entry *ent;
+	ent = GLOBAL_METHOD_CACHE(klass, id);
 	ent->seq = RCLASS_EXT(klass)->seq;
 	ent->vm_state = GET_VM_STATE_VERSION();
+	ent->defined_class = defined_class;
+	ent->mid = id;
 
 	if (UNDEFINED_METHOD_ENTRY_P(me)) {
-	    ent->mid = id;
 	    ent->me = 0;
-	    ent->defined_class = defined_class;
 	    me = 0;
 	}
 	else {
-	    ent->mid = id;
 	    ent->me = me;
-	    ent->defined_class = defined_class;
 	}
     }
 
@@ -555,7 +567,7 @@ verify_method_cache(VALUE klass, ID id, VALUE defined_class, rb_method_entry_t *
     VALUE actual_defined_class;
     method_cache_entry_t ent;
     rb_method_entry_t *actual_me =
-	rb_method_entry_get_without_cache(klass, id, &actual_defined_class, &ent);
+	rb_method_entry_get_without_cache(klass, id, &actual_defined_class);
 
     if (me != actual_me || defined_class != actual_defined_class) {
 	rb_bug("method cache verification failed");
@@ -567,19 +579,10 @@ rb_method_entry_t *
 rb_method_entry(VALUE klass, ID id, VALUE *defined_class_ptr)
 {
 #if OPT_GLOBAL_METHOD_CACHE
-    method_cache_entry_t *ent;
-
-    if (RCLASS_EXT(klass)->mc_tbl == NULL) {
-	RCLASS_EXT(klass)->mc_tbl = st_init_numtable();
-    }
-
-    if (!st_lookup(RCLASS_EXT(klass)->mc_tbl, (st_index_t)id, (st_data_t *)&ent)) {
-	ent = calloc(1, sizeof(*ent));
-	st_insert(RCLASS_EXT(klass)->mc_tbl, (st_index_t)id, (st_data_t)ent);
-    }
-
-    if (ent->seq == RCLASS_EXT(klass)->seq &&
-	ent->vm_state == GET_VM_STATE_VERSION() &&
+    struct cache_entry *ent;
+    ent = GLOBAL_METHOD_CACHE(klass, id);
+    if (ent->vm_state == GET_VM_STATE_VERSION() &&
+	ent->seq == RCLASS_EXT(klass)->seq &&
 	ent->mid == id) {
 	if (defined_class_ptr)
 	    *defined_class_ptr = ent->defined_class;
@@ -593,7 +596,7 @@ rb_method_entry(VALUE klass, ID id, VALUE *defined_class_ptr)
     method_cache_entry_t* ent = &ent_;
 #endif
 
-    return rb_method_entry_get_without_cache(klass, id, defined_class_ptr, ent);
+    return rb_method_entry_get_without_cache(klass, id, defined_class_ptr);
 }
 
 static rb_method_entry_t *