--- a/src/hotspot/share/runtime/thread.cpp	Fri May 18 15:35:32 2018 +0200
+++ b/src/hotspot/share/runtime/thread.cpp	Fri May 18 09:15:08 2018 -0700
@@ -1025,44 +1025,32 @@
 
 // Creates the initial ThreadGroup
 static Handle create_initial_thread_group(TRAPS) {
-  Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH);
-  InstanceKlass* ik = InstanceKlass::cast(k);
-
-  Handle system_instance = ik->allocate_instance_handle(CHECK_NH);
-  {
-    JavaValue result(T_VOID);
-    JavaCalls::call_special(&result,
-                            system_instance,
-                            ik,
-                            vmSymbols::object_initializer_name(),
+  Handle system_instance = JavaCalls::construct_new_instance(
+                            SystemDictionary::ThreadGroup_klass(),
                             vmSymbols::void_method_signature(),
                             CHECK_NH);
-  }
   Universe::set_system_thread_group(system_instance());
 
-  Handle main_instance = ik->allocate_instance_handle(CHECK_NH);
-  {
-    JavaValue result(T_VOID);
-    Handle string = java_lang_String::create_from_str("main", CHECK_NH);
-    JavaCalls::call_special(&result,
-                            main_instance,
-                            ik,
-                            vmSymbols::object_initializer_name(),
+  Handle string = java_lang_String::create_from_str("main", CHECK_NH);
+  Handle main_instance = JavaCalls::construct_new_instance(
+                            SystemDictionary::ThreadGroup_klass(),
                             vmSymbols::threadgroup_string_void_signature(),
                             system_instance,
                             string,
                             CHECK_NH);
-  }
   return main_instance;
 }
 
 // Creates the initial Thread
 static oop create_initial_thread(Handle thread_group, JavaThread* thread,
                                  TRAPS) {
-  Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL);
-  InstanceKlass* ik = InstanceKlass::cast(k);
+  InstanceKlass* ik = SystemDictionary::Thread_klass();
+  assert(ik->is_initialized(), "must be");
   instanceHandle thread_oop = ik->allocate_instance_handle(CHECK_NULL);
 
+  // Cannot use JavaCalls::construct_new_instance because the java.lang.Thread
+  // constructor calls Thread.current(), which must be set here for the
+  // initial thread.
   java_lang_Thread::set_thread(thread_oop(), thread);
   java_lang_Thread::set_priority(thread_oop(), NormPriority);
   thread->set_threadObj(thread_oop());
@@ -1170,10 +1158,13 @@
   assert(thread_group.not_null(), "thread group should be specified");
   assert(threadObj() == NULL, "should only create Java thread object once");
 
-  Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
-  InstanceKlass* ik = InstanceKlass::cast(k);
+  InstanceKlass* ik = SystemDictionary::Thread_klass();
+  assert(ik->is_initialized(), "must be");
   instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
 
+  // We are called from jni_AttachCurrentThread/jni_AttachCurrentThreadAsDaemon.
+  // We cannot use JavaCalls::construct_new_instance because the java.lang.Thread
+  // constructor calls Thread.current(), which must be set here.
   java_lang_Thread::set_thread(thread_oop(), this);
   java_lang_Thread::set_priority(thread_oop(), NormPriority);
   set_threadObj(thread_oop());
@@ -1187,8 +1178,8 @@
                             ik,
                             vmSymbols::object_initializer_name(),
                             vmSymbols::threadgroup_string_void_signature(),
-                            thread_group, // Argument 1
-                            name,         // Argument 2
+                            thread_group,
+                            name,
                             THREAD);
   } else {
     // Thread gets assigned name "Thread-nnn" and null target
@@ -1198,8 +1189,8 @@
                             ik,
                             vmSymbols::object_initializer_name(),
                             vmSymbols::threadgroup_runnable_void_signature(),
-                            thread_group, // Argument 1
-                            Handle(),     // Argument 2
+                            thread_group,
+                            Handle(),
                             THREAD);
   }