src/hotspot/share/runtime/vmStructs.cpp

rev 56044 : imported patch 8230184.patch
rev 56046 : v2.00 -> v2.05 (CR5/v2.05/8-for-jdk13) patches combined into one; merge with 8229212.patch; merge with jdk-14+11; merge with 8230184.patch.
rev 56048 : Add OM_CACHE_LINE_SIZE so that ObjectMonitor cache line sizes can be experimented with independently of DEFAULT_CACHE_LINE_SIZE; for SPARC and X64 configs that use 128 for DEFAULT_CACHE_LINE_SIZE, we are experimenting with 64; move _previous_owner_tid and _allocation_state fields to share the cache line with ObjectMonitor::_header; put ObjectMonitor::_ref_count on its own cache line after _owner; add 'int* count_p' parameter to deflate_monitor_list() and deflate_monitor_list_using_JT() and push counter updates down to where the ObjectMonitors are actually removed from the in-use lists; monitors_iterate() async deflation check should use negative ref_count; add 'JavaThread* target' param to deflate_per_thread_idle_monitors_using_JT() add deflate_common_idle_monitors_using_JT() to make it clear which JavaThread* is the target of the work and which is the calling JavaThread* (self); g_free_list, g_om_in_use_list and g_om_in_use_count are now static to synchronizer.cpp (reduce scope); add more diagnostic info to some assert()'s; minor code cleanups and code motion; save_om_ptr() should detect a race with a deflating thread that is bailing out and cause a retry when the ref_count field is not positive; merge with jdk-14+11; add special GC support for TestHumongousClassLoader.java; merge with 8230184.patch.

*** 908,922 ****
    /************/                                                                                                                     \
                                                                                                                                       \
    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,      _waiters,                                      jint)                                  \
    volatile_nonstatic_field(ObjectMonitor,      _recursions,                                   intptr_t)                              \
-   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*)                  \
                                                                                                                                       \
    /*********************/                                                                                                            \
--- 908,922 ----
    /************/                                                                                                                     \
                                                                                                                                       \
    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 */    \
+   nonstatic_field(ObjectMonitor,               _next_om,                                      ObjectMonitor*)                        \
+   volatile_nonstatic_field(BasicLock,          _displaced_header,                             markWord)                              \
    volatile_nonstatic_field(ObjectMonitor,      _contentions,                                  jint)                                  \
    volatile_nonstatic_field(ObjectMonitor,      _waiters,                                      jint)                                  \
    volatile_nonstatic_field(ObjectMonitor,      _recursions,                                   intptr_t)                              \
    nonstatic_field(BasicObjectLock,             _lock,                                         BasicLock)                             \
    nonstatic_field(BasicObjectLock,             _obj,                                          oop)                                   \
    static_ptr_volatile_field(ObjectSynchronizer, g_block_list,                                 PaddedObjectMonitor*)                  \
                                                                                                                                       \
    /*********************/                                                                                                            \