Set vtable in class object to null after linking.

This is follow-up work of embedding imt and vtable for
faster interface/virtual call dispatching.
Once vtable becomes embedded, the original vtable is nulled.

Change-Id: I307696657d1e283654169dbecb8f7815c42bbabc

1 files changed, 9 insertions, 1 deletions

diff --git a/runtime/mirror/class.cc b/runtime/mirror/class.cc
index 189c537..a218b1c 100644
--- a/runtime/mirror/class.cc
+++ b/runtime/mirror/class.cc
@@ -827,10 +827,18 @@ void Class::PopulateEmbeddedImtAndVTable() SHARED_LOCKS_REQUIRED(Locks::mutator_
   }
 
   table = GetVTableDuringLinking();
-  CHECK(table != nullptr);
+  CHECK(table != nullptr) << PrettyClass(this);
+  SetEmbeddedVTableLength(table->GetLength());
   for (int32_t i = 0; i < table->GetLength(); i++) {
     SetEmbeddedVTableEntry(i, table->Get(i));
   }
+
+  SetImTable(nullptr);
+  // Keep java.lang.Object class's vtable around for since it's easier
+  // to be reused by array classes during their linking.
+  if (!IsObjectClass()) {
+    SetVTable(nullptr);
+  }
 }
 
 // The pre-fence visitor for Class::CopyOf().