src/share/vm/interpreter/interpreterRuntime.cpp

*** 1191,1203 ****
--- 1191,1212 ----
      } else {
        // set handler
        method->set_signature_handler(_handlers->at(handler_index));
      }
    }
+ #ifdef ASSERT
+   {
+     // '_handlers' and '_fingerprints' are 'GrowableArray's and are NOT synchronized
+     // in any way if accessed from multiple threads. To avoid races with another
+     // thread which may change the arrays in the above, mutex protected block, we
+     // have to protect this read access here with the same mutex as well!
+     MutexLocker mu(SignatureHandlerLibrary_lock);
      assert(method->signature_handler() == Interpreter::slow_signature_handler() ||
             _handlers->find(method->signature_handler()) == _fingerprints->find(Fingerprinter(method).fingerprint()),
             "sanity check");
+   }
+ #endif
  }
  
  
  BufferBlob*              SignatureHandlerLibrary::_handler_blob = NULL;
  address                  SignatureHandlerLibrary::_handler      = NULL;