8378806: Genshen: Add scope of collection to end of cycle message in JMX notification

Reviewed-by: kdnilsen, xpeng

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

@@ -40,6 +40,22 @@
 
 ShenandoahPhaseTimings::Phase ShenandoahTimingsTracker::_current_phase = ShenandoahPhaseTimings::_invalid_phase;
 
+const char* ShenandoahGCSession::cycle_end_message(ShenandoahGenerationType type) {
+  switch (type) {
+    case NON_GEN:
+      return "end of GC cycle";
+    case GLOBAL:
+      return "end of Global GC cycle";
+    case YOUNG:
+      return "end of Young GC cycle";
+    case OLD:
+      return "end of Old GC cycle";
+    default:
+      ShouldNotReachHere();
+      return "end of GC cycle";
+  }
+}
+
 ShenandoahGCSession::ShenandoahGCSession(GCCause::Cause cause, ShenandoahGeneration* generation) :
   _heap(ShenandoahHeap::heap()),
   _generation(generation),
@@ -54,7 +70,7 @@ ShenandoahGCSession::ShenandoahGCSession(GCCause::Cause cause, ShenandoahGenerat
   _heap->trace_heap_before_gc(_tracer);
 
   _trace_cycle.initialize(_heap->cycle_memory_manager(), cause,
-          "end of GC cycle",
+          cycle_end_message(_generation->type()),
           /* allMemoryPoolsAffected */    true,
           /* recordGCBeginTime = */       true,
           /* recordPreGCUsage = */        true,

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

@@ -67,6 +67,8 @@ private:
   GCTracer* const _tracer;
 
   TraceMemoryManagerStats _trace_cycle;
+
+  static const char* cycle_end_message(ShenandoahGenerationType type);
 public:
   ShenandoahGCSession(GCCause::Cause cause, ShenandoahGeneration* generation);
   ~ShenandoahGCSession();

test/hotspot/jtreg/gc/shenandoah/mxbeans/TestCycleEndMessage.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+/*
+ * @test
+ * @summary Check that GC cycle end message contains generation name
+ * @library /test/lib /
+ * @requires vm.gc.Shenandoah
+ *
+ * @run main/othervm -Xmx128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions
+ *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=generational
+ *      TestCycleEndMessage
+ */
+
+import java.lang.management.GarbageCollectorMXBean;
+import java.lang.management.ManagementFactory;
+import java.util.concurrent.atomic.AtomicBoolean;
+import javax.management.Notification;
+import javax.management.NotificationEmitter;
+import javax.management.NotificationListener;
+import javax.management.openmbean.CompositeData;
+
+import com.sun.management.GarbageCollectionNotificationInfo;
+
+public class TestCycleEndMessage {
+
+    public static void main(String[] args) throws Exception {
+        final AtomicBoolean foundGenerationInCycle = new AtomicBoolean(false);
+
+        NotificationListener listener = new NotificationListener() {
+            @Override
+            public void handleNotification(Notification n, Object o) {
+                if (n.getType().equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION)) {
+                    GarbageCollectionNotificationInfo info = GarbageCollectionNotificationInfo.from((CompositeData) n.getUserData());
+
+                    String name = info.getGcName();
+                    String action = info.getGcAction();
+
+                    System.out.println("Received: " + name + " / " + action);
+
+                    if (name.equals("Shenandoah Cycles") &&
+                        (action.contains("Global") || action.contains("Young") || action.contains("Old"))) {
+                        foundGenerationInCycle.set(true);
+                    }
+                }
+            }
+        };
+
+        for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
+            ((NotificationEmitter) bean).addNotificationListener(listener, null, null);
+        }
+
+        System.gc();
+        Thread.sleep(2000);
+
+        if (!foundGenerationInCycle.get()) {
+            throw new IllegalStateException("Expected to find generation name (Global/Young/Old) in Shenandoah Cycles action message");
+        }
+
+        System.out.println("Test passed: Found generation name in cycle end message");
+    }
+}

test/hotspot/jtreg/gc/stringdedup/TestStringDeduplicationTools.java

@@ -129,7 +129,8 @@ class TestStringDeduplicationTools {
                 GarbageCollectionNotificationInfo info = GarbageCollectionNotificationInfo.from((CompositeData) n.getUserData());
                 // Shenandoah and Z GC also report GC pauses, skip them
                 if (info.getGcName().startsWith("Shenandoah")) {
-                    if ("end of GC cycle".equals(info.getGcAction())) {
+                    String action = info.getGcAction();
+                    if (action != null && action.contains("GC cycle")) {
                         gcCount++;
                     }
                 } else if (info.getGcName().startsWith("ZGC")) {