8357910: LoaderConstraintsTest.java fails when run with TEST_THREAD_FACTORY=Virtual

test/hotspot/jtreg/ProblemList-Virtual.txt

@@ -99,7 +99,6 @@ gc/arguments/TestNewSizeThreadIncrease.java 0000000 generic-all
 gc/g1/TestSkipRebuildRemsetPhase.java 0000000 generic-all
 runtime/classFileParserBug/TestEmptyBootstrapMethodsAttr.java 8346442 generic-all
 runtime/ErrorHandling/MachCodeFramesInErrorFile.java 0000000 generic-all
-runtime/logging/LoaderConstraintsTest.java 8346442 generic-all
 runtime/Thread/AsyncExceptionOnMonitorEnter.java 0000000 generic-all
 runtime/Thread/StopAtExit.java 0000000 generic-all
 runtime/handshake/HandshakeWalkStackTest.java 0000000 generic-all

test/hotspot/jtreg/runtime/logging/LoaderConstraintsTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2025, Oracle and/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
@@ -38,6 +38,7 @@
 import jdk.test.lib.process.OutputAnalyzer;
 import java.lang.ref.WeakReference;
 import java.lang.reflect.Method;
+import java.lang.reflect.Constructor;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -49,22 +50,25 @@ public class LoaderConstraintsTest {
     private static ProcessBuilder pb;
     private static class ClassUnloadTestMain {
         public static void main(String... args) throws Exception {
-            String className = "test.Empty";
             ClassLoader cl = ClassUnloadCommon.newClassLoader();
-            Class<?> c = cl.loadClass(className);
-            cl = null; c = null;
-            ClassUnloadCommon.triggerUnloading();
+            Class<?> c = cl.loadClass("test.Empty");
+            // Causes class test.Empty to be linked, which triggers the
+            // constraint on class String due to override of toString().
+            Constructor<?> constructor = c.getDeclaredConstructor();
         }
     }
 
     // Use the same command-line heap size setting as ../ClassUnload/UnloadTest.java
     static ProcessBuilder exec(String... args) throws Exception {
+        String classPath = System.getProperty("test.class.path", ".");
+
         List<String> argsList = new ArrayList<>();
         Collections.addAll(argsList, args);
         Collections.addAll(argsList, "-Xmn8m");
         Collections.addAll(argsList, "-Xbootclasspath/a:.");
         Collections.addAll(argsList, "-XX:+UnlockDiagnosticVMOptions");
         Collections.addAll(argsList, "-XX:+WhiteBoxAPI");
+        Collections.addAll(argsList, "-Dtest.class.path=" + classPath);
         Collections.addAll(argsList, ClassUnloadTestMain.class.getName());
         return ProcessTools.createLimitedTestJavaProcessBuilder(argsList);
     }
@@ -75,13 +79,12 @@ public static void main(String... args) throws Exception {
         pb = exec("-Xlog:class+loader+constraints=info");
         out = new OutputAnalyzer(pb.start());
         out.shouldHaveExitValue(0);
-        out.shouldContain("[class,loader,constraints] adding new constraint for name: java/lang/Class, loader[0]: 'app', loader[1]: 'bootstrap'");
+        out.stdoutShouldMatch("\\[class,loader,constraints\\] adding new constraint for name: java/lang/String, loader\\[0\\]: 'ClassUnloadCommonClassLoader' @[\\da-f]+, loader\\[1\\]: 'bootstrap'");
 
         // -Xlog:class+loader+constraints=off
         pb = exec("-Xlog:class+loader+constraints=off");
         out = new OutputAnalyzer(pb.start());
         out.shouldHaveExitValue(0);
         out.shouldNotContain("[class,loader,constraints]");
-
     }
 }