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src/hotspot/share/runtime/synchronizer.hpp

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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.

@@ -33,11 +33,17 @@
 
 class ObjectMonitor;
 class ObjectMonitorHandle;
 class ThreadsList;
 
-typedef PaddedEnd<ObjectMonitor, DEFAULT_CACHE_LINE_SIZE> PaddedObjectMonitor;
+#ifndef OM_CACHE_LINE_SIZE
+// Use DEFAULT_CACHE_LINE_SIZE if not already specified for
+// the current build platform.
+#define OM_CACHE_LINE_SIZE DEFAULT_CACHE_LINE_SIZE
+#endif
+
+typedef PaddedEnd<ObjectMonitor, OM_CACHE_LINE_SIZE> PaddedObjectMonitor;
 
 struct DeflateMonitorCounters {
   int n_in_use;              // currently associated with objects
   int n_in_circulation;      // extant
   int n_scavenged;           // reclaimed (global and per-thread)

@@ -140,23 +146,25 @@
   // GC: we current use aggressive monitor deflation policy
   // Basically we deflate all monitors that are not busy.
   // An adaptive profile-based deflation policy could be used if needed
   static void deflate_idle_monitors(DeflateMonitorCounters* counters);
   static void deflate_global_idle_monitors_using_JT();
-  static void deflate_per_thread_idle_monitors_using_JT();
-  static void deflate_common_idle_monitors_using_JT(bool is_global, JavaThread* self);
+  static void deflate_per_thread_idle_monitors_using_JT(JavaThread* target);
+  static void deflate_common_idle_monitors_using_JT(bool is_global, JavaThread* target);
   static void deflate_thread_local_monitors(Thread* thread, DeflateMonitorCounters* counters);
   static void prepare_deflate_idle_monitors(DeflateMonitorCounters* counters);
   static void finish_deflate_idle_monitors(DeflateMonitorCounters* counters);
 
   // For a given monitor list: global or per-thread, deflate idle monitors
   static int deflate_monitor_list(ObjectMonitor** list_p,
+                                  int* count_p,
                                   ObjectMonitor** free_head_p,
                                   ObjectMonitor** free_tail_p);
   // For a given in-use monitor list: global or per-thread, deflate idle
   // monitors using a JavaThread.
   static int deflate_monitor_list_using_JT(ObjectMonitor** list_p,
+                                           int* count_p,
                                            ObjectMonitor** free_head_p,
                                            ObjectMonitor** free_tail_p,
                                            ObjectMonitor** saved_mid_in_use_p);
   static bool deflate_monitor(ObjectMonitor* mid, oop obj,
                               ObjectMonitor** free_head_p,

@@ -201,17 +209,10 @@
   friend class SynchronizerTest;
 
   enum { _BLOCKSIZE = 128 };
   // global list of blocks of monitors
   static PaddedObjectMonitor* volatile g_block_list;
-  // global monitor free list
-  static ObjectMonitor* volatile g_free_list;
-  // global monitor in-use list, for moribund threads,
-  // monitors they inflated need to be scanned for deflation
-  static ObjectMonitor* volatile g_om_in_use_list;
-  // count of entries in g_om_in_use_list
-  static int g_om_in_use_count;
   static volatile bool _is_async_deflation_requested;
   static volatile bool _is_special_deflation_requested;
   static jlong         _last_async_deflation_time_ns;
 
   // Process oops in all global used monitors (i.e. moribund thread's monitors)
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