--- /dev/null	2019-07-08 11:17:54.000000000 -0700
+++ new/src/hotspot/share/runtime/notificationThread.cpp	2019-07-08 11:17:53.000000000 -0700
@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "memory/universe.hpp"
+#include "runtime/interfaceSupport.inline.hpp"
+#include "runtime/javaCalls.hpp"
+#include "runtime/notificationThread.hpp"
+#include "services/diagnosticArgument.hpp"
+#include "services/diagnosticFramework.hpp"
+#include "services/gcNotifier.hpp"
+#include "services/lowMemoryDetector.hpp"
+
+NotificationThread* NotificationThread::_instance = NULL;
+
+void NotificationThread::initialize() {
+  EXCEPTION_MARK;
+
+  const char* name = "Notification Thread";
+  Handle string = java_lang_String::create_from_str(name, CHECK);
+
+  // Initialize thread_oop to put it into the system threadGroup
+  Handle thread_group (THREAD, Universe::system_thread_group());
+  Handle thread_oop = JavaCalls::construct_new_instance(
+                          SystemDictionary::Thread_klass(),
+                          vmSymbols::threadgroup_string_void_signature(),
+                          thread_group,
+                          string,
+                          CHECK);
+  
+  Klass* group = SystemDictionary::ThreadGroup_klass();
+  JavaValue result(T_VOID);
+  JavaCalls::call_special(&result,
+                          thread_group,
+                          group,
+                          vmSymbols::add_method_name(),
+                          vmSymbols::thread_void_signature(),
+                          thread_oop,
+                          THREAD);
+  {
+    MutexLocker mu(Threads_lock);
+    NotificationThread* thread =  new NotificationThread(&notification_thread_entry);
+
+    // At this point it may be possible that no osthread was created for the
+    // JavaThread due to lack of memory. We would have to throw an exception
+    // in that case. However, since this must work and we do not allow
+    // exceptions anyway, check and abort if this fails.
+    if (thread == NULL || thread->osthread() == NULL) {
+      vm_exit_during_initialization("java.lang.OutOfMemoryError",
+                                    os::native_thread_creation_failed_msg());
+    }
+
+    java_lang_Thread::set_thread(thread_oop(), thread);
+    java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
+    java_lang_Thread::set_daemon(thread_oop());
+    thread->set_threadObj(thread_oop());
+    _instance = thread;
+
+    Threads::add(thread);
+    Thread::start(thread);
+  }
+}
+
+
+
+void NotificationThread::notification_thread_entry(JavaThread* jt, TRAPS) {
+  while (true) {
+    bool sensors_changed = false;
+    bool has_dcmd_notification_event = false;
+    bool has_gc_notification_event = false;
+    {
+      // Need state transition ThreadBlockInVM so that this thread
+      // will be handled by safepoint correctly when this thread is
+      // notified at a safepoint.
+
+      ThreadBlockInVM tbivm(jt);
+
+      MonitorLocker ml(Notification_lock, Mutex::_no_safepoint_check_flag);
+      // Process all available work on each (outer) iteration, rather than
+      // only the first recognized bit of work, to avoid frequently true early
+      // tests from potentially starving later work.  Hence the use of
+      // arithmetic-or to combine results; we don't want short-circuiting.
+      while (((sensors_changed = LowMemoryDetector::has_pending_requests()) |
+              (has_dcmd_notification_event = DCmdFactory::has_pending_jmx_notification()) |
+              (has_gc_notification_event = GCNotifier::has_event()))
+             == 0) {
+        // Wait until notified that there is some work to do.
+        ml.wait();
+      }
+
+    }
+
+    if (sensors_changed) {
+      LowMemoryDetector::process_sensor_changes(jt);
+    }
+        
+    if(has_gc_notification_event) {
+      GCNotifier::sendNotification(CHECK);
+    }
+    
+    if(has_dcmd_notification_event) {
+      DCmdFactory::send_notification(CHECK);
+    }
+
+  }
+}
+