--- a/src/hotspot/os/windows/os_windows.hpp	Wed Aug 14 01:40:29 2019 +0000
+++ b/src/hotspot/os/windows/os_windows.hpp	Wed Aug 14 00:18:00 2019 -0400
@@ -187,18 +187,34 @@
 
 } ;
 
-// Platform specific implementation that underpins VM Monitor/Mutex class
-class PlatformMonitor : public CHeapObj<mtSynchronizer> {
+// Platform specific implementations that underpin VM Mutex/Monitor classes
+
+class PlatformMutex : public CHeapObj<mtSynchronizer> {
+  // Disable copying
+  PlatformMutex(const PlatformMutex&);
+  PlatformMutex& operator=(const PlatformMutex&);
+
+ protected:
+  CRITICAL_SECTION   _mutex; // Native mutex for locking
+
+ public:
+  PlatformMutex();
+  ~PlatformMutex();
+  void lock();
+  void unlock();
+  bool try_lock();
+};
+
+class PlatformMonitor : public PlatformMutex {
  private:
-  CRITICAL_SECTION   _mutex; // Native mutex for locking
   CONDITION_VARIABLE _cond;  // Native condition variable for blocking
+  // Disable copying
+  PlatformMonitor(const PlatformMonitor&);
+  PlatformMonitor& operator=(const PlatformMonitor&);
 
  public:
   PlatformMonitor();
   ~PlatformMonitor();
-  void lock();
-  void unlock();
-  bool try_lock();
   int wait(jlong millis);
   void notify();
   void notify_all();