src/hotspot/share/classfile/dictionary.cpp

Concurrent class unloading

   }
 }
 
 
 void Dictionary::do_unloading() {
-  assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
+  MutexLockerEx m(SystemDictionary_lock);
+  assert(UseZGC || SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
 
   // The NULL class loader doesn't initiate loading classes from other class loaders
   if (loader_data() == ClassLoaderData::the_null_class_loader_data()) {
     return;
   }