Backport 06ebb170bac3879dc1e378b48b1c7ef006070c86

Author: duke

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

@@ -332,6 +332,8 @@ void ShenandoahGenerationalControlThread::run_service() {
     }
   }
 
+  set_gc_mode(stopped);
+
   // Wait for the actual stop(), can't leave run_service() earlier.
   while (!should_terminate()) {
     os::naked_short_sleep(ShenandoahControlIntervalMin);
@@ -827,6 +829,7 @@ const char* ShenandoahGenerationalControlThread::gc_mode_name(ShenandoahGenerati
     case stw_full:          return "full";
     case servicing_old:     return "old";
     case bootstrapping_old: return "bootstrap";
+    case stopped:           return "stopped";
     default:                return "unknown";
   }
 }

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

@@ -48,7 +48,8 @@ class ShenandoahGenerationalControlThread: public ShenandoahController {
     stw_degenerated,
     stw_full,
     bootstrapping_old,
-    servicing_old
+    servicing_old,
+    stopped
   } GCMode;
 
 private: