--- old/src/hotspot/share/gc/shared/concurrentGCThread.cpp	2019-03-27 14:17:37.583202603 +0100
+++ new/src/hotspot/share/gc/shared/concurrentGCThread.cpp	2019-03-27 14:17:37.244191513 +0100
@@ -30,7 +30,6 @@
 #include "runtime/os.hpp"
 
 ConcurrentGCThread::ConcurrentGCThread() :
-    _monitor(Monitor::leaf, "ConcurrentGCThread"),
     _should_terminate(false),
     _has_terminated(false) {}
 
@@ -51,7 +50,7 @@
   run_service();
 
   // Signal thread has terminated
-  MonitorLockerEx ml(&_monitor);
+  MonitorLockerEx ml(Terminator_lock);
   OrderAccess::release_store(&_has_terminated, true);
   ml.notify_all();
 }
@@ -66,7 +65,7 @@
   stop_service();
 
   // Wait for thread to terminate
-  MonitorLockerEx ml(&_monitor);
+  MonitorLockerEx ml(Terminator_lock);
   while (!_has_terminated) {
     ml.wait();
   }
--- old/src/hotspot/share/gc/shared/concurrentGCThread.hpp	2019-03-27 14:17:38.087219088 +0100
+++ new/src/hotspot/share/gc/shared/concurrentGCThread.hpp	2019-03-27 14:17:37.748208000 +0100
@@ -25,12 +25,10 @@
 #ifndef SHARE_GC_SHARED_CONCURRENTGCTHREAD_HPP
 #define SHARE_GC_SHARED_CONCURRENTGCTHREAD_HPP
 
-#include "runtime/mutex.hpp"
 #include "runtime/thread.hpp"
 
 class ConcurrentGCThread: public NamedThread {
 private:
-  Monitor       _monitor;
   volatile bool _should_terminate;
   volatile bool _has_terminated;
 
--- old/src/hotspot/share/runtime/thread.cpp	2019-03-27 14:17:38.570234888 +0100
+++ new/src/hotspot/share/runtime/thread.cpp	2019-03-27 14:17:38.223223537 +0100
@@ -1506,7 +1506,7 @@
   {
     MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
     _watcher_thread = NULL;
-    Terminator_lock->notify();
+    Terminator_lock->notify_all();
   }
 }