From 21f448d6ef707335d6e5fe0888030aaa0fa3208f Mon Sep 17 00:00:00 2001
From: "Daniel D. Daugherty" <daniel.daugherty@oracle.com>
Date: Sat, 14 Nov 2020 10:26:18 -0500
Subject: [PATCH] 8244679: JVM/TI GetCurrentContendedMonitor/contmon001 failed
 due to "(IsSameObject#3) unexpected monitor object: 0x000000562336DBA8"

---
 .../jvmti/GetCurrentContendedMonitor/contmon001.java   | 10 ++++++++++
 .../jvmti/GetCurrentContendedMonitor/contmon002.java   |  8 ++++++++
 2 files changed, 18 insertions(+)

diff --git a/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetCurrentContendedMonitor/contmon001.java b/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetCurrentContendedMonitor/contmon001.java
index 320190d05c8..6440983ab9a 100644
--- a/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetCurrentContendedMonitor/contmon001.java
+++ b/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetCurrentContendedMonitor/contmon001.java
@@ -42,6 +42,7 @@ public class contmon001 {
         }
     }
 
+    public static Wicket dummyBarrier;
     public static Wicket startingBarrier;
     public static Wicket waitingBarrier;
     static Object lockFld = new Object();
@@ -75,10 +76,15 @@ public class contmon001 {
             out.println("Check #1 done");
 
         contmon001a thr = new contmon001a();
+        dummyBarrier = new Wicket();
         startingBarrier = new Wicket();
         waitingBarrier = new Wicket();
 
         thr.start();
+        if (true || DEBUG_MODE)
+            out.println("\nWaiting for auxiliary thread using dummy to load classes...");
+        dummyBarrier.waitFor();
+
         if (DEBUG_MODE)
             out.println("\nWaiting for auxiliary thread ...");
         startingBarrier.waitFor();
@@ -130,6 +136,10 @@ class contmon001a extends Thread {
     private volatile boolean flag = true;
 
     public void run() {
+        if (true || contmon001.DEBUG_MODE)
+            contmon001.out.println("\nnotifying main thread using dummy to load classes...");
+        contmon001.dummyBarrier.unlock();
+
         if (contmon001.DEBUG_MODE)
             contmon001.out.println("check #2: verifying a contended monitor of current auxiliary thread ...");
         contmon001.checkMon(2, currentThread(), null);
diff --git a/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetCurrentContendedMonitor/contmon002.java b/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetCurrentContendedMonitor/contmon002.java
index 3b9296d7083..de459bbe4dc 100644
--- a/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetCurrentContendedMonitor/contmon002.java
+++ b/test/hotspot/jtreg/vmTestbase/nsk/jvmti/GetCurrentContendedMonitor/contmon002.java
@@ -42,6 +42,7 @@ public class contmon002 {
         }
     }
 
+    public static Wicket dummyBarrier;
     public static Wicket startingBarrier;
 
     public static void main(String[] args) {
@@ -54,8 +55,12 @@ public class contmon002 {
         checkMon(1, Thread.currentThread());
 
         contmon002a thr = new contmon002a();
+        dummyBarrier = new Wicket();
         startingBarrier = new Wicket();
         thr.start();
+        System.out.println("\nWaiting for auxiliary thread using dummy to load classes...");
+        dummyBarrier.waitFor();
+
         startingBarrier.waitFor();
         checkMon(2, thr);
         thr.letItGo();
@@ -89,6 +94,9 @@ class contmon002a extends Thread {
     }
 
     public void run() {
+        System.out.println("\nnotifying main thread using dummy to load classes...");
+        contmon002.dummyBarrier.unlock();
+
         meth();
     }
 
-- 
2.28.0