src/hotspot/share/runtime/synchronizer.hpp

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.
rev 56049 : Merge the remainder of the lock-free monitor list changes from v2.06 with v2.06a and v2.06b after running the changes through the edit scripts; merge pieces from dcubed.monitor_deflate_conc.v2.06d in dcubed.monitor_deflate_conc.v2.06[ac]; merge pieces from dcubed.monitor_deflate_conc.v2.06e into dcubed.monitor_deflate_conc.v2.06c; merge with jdk-14+11; test work around for test/jdk/tools/jlink/multireleasejar/JLinkMultiReleaseJarTest.java should not been needed anymore.

@@ -42,14 +42,14 @@
 #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)
-  int per_thread_scavenged;  // per-thread scavenge total
+  volatile int n_in_use;              // currently associated with objects
+  volatile int n_in_circulation;      // extant
+  volatile int n_scavenged;           // reclaimed (global and per-thread)
+  volatile int per_thread_scavenged;  // per-thread scavenge total
   double per_thread_times;   // per-thread scavenge times
 };
 
 class ObjectSynchronizer : AllStatic {
   friend class VMStructs;

@@ -153,18 +153,18 @@
   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,
+  static int deflate_monitor_list(ObjectMonitor* volatile * list_p,
+                                  int volatile * 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,
+  static int deflate_monitor_list_using_JT(ObjectMonitor* volatile * list_p,
+                                           int volatile * 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,

@@ -197,15 +197,15 @@
                                                    outputStream * out,
                                                    int *error_cnt_p);
   static void chk_per_thread_free_list_and_count(JavaThread *jt,
                                                  outputStream * out,
                                                  int *error_cnt_p);
-  static void log_in_use_monitor_details(outputStream * out, bool on_exit);
+  static void log_in_use_monitor_details(outputStream * out);
   static int  log_monitor_list_counts(outputStream * out);
   static int  verify_objmon_isinpool(ObjectMonitor *addr) PRODUCT_RETURN0;
 
-  static void do_safepoint_work(DeflateMonitorCounters* _counters);
+  static void do_safepoint_work(DeflateMonitorCounters* counters);
 
  private:
   friend class SynchronizerTest;
 
   enum { _BLOCKSIZE = 128 };

@@ -213,14 +213,17 @@
   static PaddedObjectMonitor* volatile g_block_list;
   static volatile bool _is_async_deflation_requested;
   static volatile bool _is_special_deflation_requested;
   static jlong         _last_async_deflation_time_ns;
 
+  // Function to prepend new blocks to the appropriate lists:
+  static void prepend_block_to_lists(PaddedObjectMonitor* new_blk);
+
   // Process oops in all global used monitors (i.e. moribund thread's monitors)
   static void global_used_oops_do(OopClosure* f);
   // Process oops in monitors on the given list
-  static void list_oops_do(ObjectMonitor* list, OopClosure* f);
+  static void list_oops_do(ObjectMonitor* list, int count, OopClosure* f);
 
   // Support for SynchronizerTest access to GVars fields:
   static u_char* get_gvars_addr();
   static u_char* get_gvars_hc_sequence_addr();
   static size_t get_gvars_size();