8236851: Shenandoah: More details in Traversal GC event messages

Reviewed-by: shade

Author: rkennke

src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp

@@ -2805,7 +2805,7 @@ void ShenandoahHeap::entry_init_traversal() {
   ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
   ShenandoahGCPhase phase(ShenandoahPhaseTimings::init_traversal_gc);
 
-  static const char* msg = "Pause Init Traversal";
+  static const char* msg = init_traversal_event_message();
   GCTraceTime(Info, gc) time(msg, gc_timer());
   EventMark em("%s", msg);
 
@@ -2820,7 +2820,7 @@ void ShenandoahHeap::entry_final_traversal() {
   ShenandoahGCPhase total_phase(ShenandoahPhaseTimings::total_pause);
   ShenandoahGCPhase phase(ShenandoahPhaseTimings::final_traversal_gc);
 
-  static const char* msg = "Pause Final Traversal";
+  static const char* msg = final_traversal_event_message();
   GCTraceTime(Info, gc) time(msg, gc_timer());
   EventMark em("%s", msg);
 
@@ -2972,7 +2972,7 @@ void ShenandoahHeap::entry_preclean() {
 }
 
 void ShenandoahHeap::entry_traversal() {
-  static const char* msg = "Concurrent traversal";
+  static const char* msg = conc_traversal_event_message();
   GCTraceTime(Info, gc) time(msg, NULL, GCCause::_no_gc, true);
   EventMark em("%s", msg);
 
@@ -3141,6 +3141,51 @@ const char* ShenandoahHeap::conc_mark_event_message() const {
   }
 }
 
+const char* ShenandoahHeap::init_traversal_event_message() const {
+  bool proc_refs = process_references();
+  bool unload_cls = unload_classes();
+
+  if (proc_refs && unload_cls) {
+    return "Pause Init Traversal (process weakrefs) (unload classes)";
+  } else if (proc_refs) {
+    return "Pause Init Traversal (process weakrefs)";
+  } else if (unload_cls) {
+    return "Pause Init Traversal (unload classes)";
+  } else {
+    return "Pause Init Traversal";
+  }
+}
+
+const char* ShenandoahHeap::final_traversal_event_message() const {
+  bool proc_refs = process_references();
+  bool unload_cls = unload_classes();
+
+  if (proc_refs && unload_cls) {
+    return "Pause Final Traversal (process weakrefs) (unload classes)";
+  } else if (proc_refs) {
+    return "Pause Final Traversal (process weakrefs)";
+  } else if (unload_cls) {
+    return "Pause Final Traversal (unload classes)";
+  } else {
+    return "Pause Final Traversal";
+  }
+}
+
+const char* ShenandoahHeap::conc_traversal_event_message() const {
+  bool proc_refs = process_references();
+  bool unload_cls = unload_classes();
+
+  if (proc_refs && unload_cls) {
+    return "Concurrent Traversal (process weakrefs) (unload classes)";
+  } else if (proc_refs) {
+    return "Concurrent Traversal (process weakrefs)";
+  } else if (unload_cls) {
+    return "Concurrent Traversal (unload classes)";
+  } else {
+    return "Concurrent Traversal";
+  }
+}
+
 const char* ShenandoahHeap::degen_event_message(ShenandoahDegenPoint point) const {
   switch (point) {
     case _degenerated_unset:

src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp

@@ -438,6 +438,9 @@ class ShenandoahHeap : public CollectedHeap {
   const char* init_mark_event_message() const;
   const char* final_mark_event_message() const;
   const char* conc_mark_event_message() const;
+  const char* init_traversal_event_message() const;
+  const char* final_traversal_event_message() const;
+  const char* conc_traversal_event_message() const;
   const char* degen_event_message(ShenandoahDegenPoint point) const;
 
 // ---------- GC subsystems