8354234: Remove friends for ObjectMonitor

Reviewed-by: aboldtch, dholmes

Author: coleenp

src/hotspot/share/runtime/objectMonitor.hpp

@@ -148,9 +148,6 @@ class ObjectWaiter : public CHeapObj<mtThread> {
 #define OM_CACHE_LINE_SIZE DEFAULT_CACHE_LINE_SIZE
 
 class ObjectMonitor : public CHeapObj<mtObjectMonitor> {
-  friend class LightweightSynchronizer;
-  friend class ObjectSynchronizer;
-  friend class ObjectWaiter;
   friend class VMStructs;
   JVMCI_ONLY(friend class JVMCIVMStructs;)
 
@@ -424,13 +421,12 @@ class ObjectMonitor : public CHeapObj<mtObjectMonitor> {
   bool      short_fixed_spin(JavaThread* current, int spin_count, bool adapt);
   void      exit_epilog(JavaThread* current, ObjectWaiter* Wakee);
 
+ public:
   // Deflation support
   bool      deflate_monitor(Thread* current);
- private:
   void      install_displaced_markword_in_object(const oop obj);
 
   // JFR support
-public:
   static bool is_jfr_excluded(const Klass* monitor_klass);
 };
 

src/hotspot/share/runtime/synchronizer.cpp

@@ -423,7 +423,8 @@ bool ObjectSynchronizer::quick_enter_legacy(oop obj, BasicLock* lock, JavaThread
     // Case: TLE inimical operations such as nested/recursive synchronization
 
     if (m->has_owner(current)) {
-      m->_recursions++;
+      int recursions = m->recursions();
+      m->set_recursions(++recursions);
       current->inc_held_monitor_count();
       return true;
     }
@@ -440,7 +441,7 @@ bool ObjectSynchronizer::quick_enter_legacy(oop obj, BasicLock* lock, JavaThread
     lock->set_displaced_header(markWord::unused_mark());
 
     if (!m->has_owner() && m->try_set_owner(current)) {
-      assert(m->_recursions == 0, "invariant");
+      assert(m->recursions() == 0, "invariant");
       current->inc_held_monitor_count();
       return true;
     }