--- old/src/hotspot/share/runtime/objectMonitor.hpp	2019-05-02 15:04:26.038393078 -0400
+++ new/src/hotspot/share/runtime/objectMonitor.hpp	2019-05-02 15:04:25.586393094 -0400
@@ -168,13 +168,15 @@
 
   volatile jint  _contentions;      // Number of active contentions in enter(). It is used by is_busy()
                                     // along with other fields to determine if an ObjectMonitor can be
-                                    // deflated. See ObjectSynchronizer::deflate_monitor().
+                                    // deflated. See ObjectSynchronizer::deflate_monitor() and
+                                    // ObjectSynchronizer::deflate_monitor_using_JT().
  protected:
   ObjectWaiter * volatile _WaitSet; // LL of threads wait()ing on the monitor
   volatile jint  _waiters;          // number of waiting threads
  private:
   volatile int _WaitSetLock;        // protects Wait Queue - simple spinlock
-  volatile jint _ref_count;         // ref count for ObjectMonitor*
+  volatile jint _ref_count;         // ref count for ObjectMonitor* and used by the async deflation
+                                    // protocol. See ObjectSynchronizer::deflate_monitor_using_JT().
   typedef enum {
     Free = 0,  // Free must be 0 for monitor to be free after memset(..,0,..).
     New,
@@ -249,16 +251,13 @@
     return _contentions|_waiters|intptr_t(_owner)|intptr_t(_cxq)|intptr_t(_EntryList);
   }
 
-  // Version of is_busy() that accounts for special values in
-  // _contentions and _owner when AsyncDeflateIdleMonitors is enabled.
+  // Version of is_busy() that accounts for the special value in
+  // _owner when AsyncDeflateIdleMonitors is enabled.
   intptr_t is_busy_async() const {
-    intptr_t ret_code = _waiters | intptr_t(_cxq) | intptr_t(_EntryList);
+    intptr_t ret_code = _contentions | _waiters | intptr_t(_cxq) | intptr_t(_EntryList);
     if (!AsyncDeflateIdleMonitors) {
-      ret_code |= _contentions | intptr_t(_owner);
+      ret_code |= intptr_t(_owner);
     } else {
-      if (_contentions > 0) {
-        ret_code |= _contentions;
-      }
       if (_owner != DEFLATER_MARKER) {
         ret_code |= intptr_t(_owner);
       }
@@ -326,7 +325,7 @@
   void      clear();
   void      clear_using_JT();
 
-  bool      enter(TRAPS);  // Returns false if monitor is being async deflated and caller should retry locking the object.
+  void      enter(TRAPS);
   void      exit(bool not_suspended, TRAPS);
   void      wait(jlong millis, bool interruptable, TRAPS);
   void      notify(TRAPS);
@@ -334,7 +333,7 @@
 
 // Use the following at your own risk
   intptr_t  complete_exit(TRAPS);
-  bool      reenter(intptr_t recursions, TRAPS);  // Returns false if monitor is being async deflated and caller should retry locking the object.
+  void      reenter(intptr_t recursions, TRAPS);
 
  private:
   void      AddWaiter(ObjectWaiter * waiter);