src/hotspot/share/runtime/vmStructs.cpp

rev 59077 : 8153224.v2.09b.patch combined with 8153224.v2.10.patch; merge with jdk-15+21.
rev 59078 : eosterlund v2.10 CR: reorganize deflate_monitor_using_JT() to use "early exit" style; dcubed - clarify/fix/rearrange a few comments in deflate_monitor_using_JT(); eosterlund v2.10 CR: simplify install_displaced_markword_in_object() and save_om_ptr(); save_om_ptr()'s call to install_displaced_markword_in_object() can race with the deflater thread's clearing of the object field so handle that; fold 8153224.OMHandle_experiment into 8153224.v2.11.patch; merge with jdk-15+21.

@@ -92,10 +92,11 @@
 #include "runtime/os.hpp"
 #include "runtime/perfMemory.hpp"
 #include "runtime/serviceThread.hpp"
 #include "runtime/sharedRuntime.hpp"
 #include "runtime/stubRoutines.hpp"
+#include "runtime/synchronizer.hpp"
 #include "runtime/thread.inline.hpp"
 #include "runtime/threadSMR.hpp"
 #include "runtime/vframeArray.hpp"
 #include "runtime/vmStructs.hpp"
 #include "utilities/globalDefinitions.hpp"

@@ -897,18 +898,18 @@
   /************/                                                                                                                     \
                                                                                                                                      \
   volatile_nonstatic_field(ObjectMonitor,      _header,                                       markWord)                              \
   unchecked_nonstatic_field(ObjectMonitor,     _object,                                       sizeof(void *)) /* NOTE: no type */    \
   unchecked_nonstatic_field(ObjectMonitor,     _owner,                                        sizeof(void *)) /* NOTE: no type */    \
-  volatile_nonstatic_field(ObjectMonitor,      _contentions,                                  jint)                                  \
+  volatile_nonstatic_field(ObjectMonitor,      _next_om,                                      ObjectMonitor*)                        \
+  volatile_nonstatic_field(BasicLock,          _displaced_header,                             markWord)                              \
+  nonstatic_field(ObjectMonitor,               _contentions,                                  jint)                                  \
   volatile_nonstatic_field(ObjectMonitor,      _waiters,                                      jint)                                  \
   volatile_nonstatic_field(ObjectMonitor,      _recursions,                                   intx)                                  \
-  nonstatic_field(ObjectMonitor,               _next_om,                                      ObjectMonitor*)                        \
-  volatile_nonstatic_field(BasicLock,          _displaced_header,                             markWord)                              \
   nonstatic_field(BasicObjectLock,             _lock,                                         BasicLock)                             \
   nonstatic_field(BasicObjectLock,             _obj,                                          oop)                                   \
-  static_ptr_volatile_field(ObjectSynchronizer, g_block_list,                                 PaddedObjectMonitor*)                  \
+  static_field(ObjectSynchronizer,             g_block_list,                                  PaddedObjectMonitor*)                  \
                                                                                                                                      \
   /*********************/                                                                                                            \
   /* Matcher (C2 only) */                                                                                                            \
   /*********************/                                                                                                            \
                                                                                                                                      \