Investigate & fix issues around usage_count and deoptimization_count

runtime/vm/class_finalizer.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/class_finalizer.h"
 
 #include "vm/code_generator.h"
 #include "vm/flags.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
@@ skipping 17 matching lines @@
       GrowableObjectArray::Handle(object_store->pending_classes());
   return classes.Length() == 0;
 }
 
 
 // Removes optimized code once we load more classes, since CHA based
 // optimizations may have become invalid.
 // Only methods which owner classes where subclasses can be invalid.
 // TODO(srdjan): Be even more precise by recording the exact CHA optimization.
 static void RemoveCHAOptimizedCode(
+    const Class& subclass,
     const GrowableArray<intptr_t>& added_subclass_to_cids) {
   ASSERT(FLAG_use_cha_deopt);
-  if (added_subclass_to_cids.is_empty()) return;
+  if (added_subclass_to_cids.is_empty()) {
+    return;
+  }
   // Switch all functions' code to unoptimized.
   const ClassTable& class_table = *Isolate::Current()->class_table();
   Class& cls = Class::Handle();
   for (intptr_t i = 0; i < added_subclass_to_cids.length(); i++) {
     intptr_t cid = added_subclass_to_cids[i];
     cls = class_table.At(cid);
     ASSERT(!cls.IsNull());
-    cls.DisableCHAOptimizedCode();
+    cls.DisableCHAOptimizedCode(subclass);
   }
 }
 
 
 void AddSuperType(const AbstractType& type,
                   GrowableArray<intptr_t>* finalized_super_classes) {
   ASSERT(type.HasResolvedTypeClass());
   ASSERT(!type.IsDynamicType());
   if (type.IsObjectType()) {
     return;
@@ skipping 2346 matching lines @@
   // Resolve and finalize all member types.
   ResolveAndFinalizeMemberTypes(cls);
   // Run additional checks after all types are finalized.
   if (cls.is_const()) {
     CheckForLegalConstClass(cls);
   }
   if (FLAG_use_cha_deopt) {
     GrowableArray<intptr_t> cids;
     CollectFinalizedSuperClasses(cls, &cids);
     CollectImmediateSuperInterfaces(cls, &cids);
-    RemoveCHAOptimizedCode(cids);
+    RemoveCHAOptimizedCode(cls, cids);
   }
   if (cls.is_enum_class()) {
     AllocateEnumValues(cls);
   }
 }
 
 
 // Allocate instances for each enumeration value, and populate the
 // static field 'values'.
 // By allocating the instances programmatically, we save an implicit final
@@ skipping 794 matching lines @@
   ASSERT(fields_array.Length() == ByteBuffer::NumberOfFields());
   field ^= fields_array.At(0);
   ASSERT(field.Offset() == ByteBuffer::data_offset());
   name ^= field.name();
   expected_name ^= String::New("_data");
   ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name));
 #endif
 }
 
 }  // namespace dart