[6411] Java 21: virtual threads for sampler execution + API migration

build-logic/build-parameters/build.gradle.kts

@@ -38,7 +38,7 @@ buildParameters {
         description.set("Collect test coverage")
     }
     integer("targetJavaVersion") {
-        defaultValue.set(17)
+        defaultValue.set(21)
         mandatory.set(true)
         description.set("Java version for source and target compatibility")
     }

src/components/src/main/java/org/apache/jmeter/visualizers/backend/influxdb/HttpMetricsSender.java

@@ -17,6 +17,7 @@
 
 package org.apache.jmeter.visualizers.backend.influxdb;
 
+import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
@@ -120,7 +121,7 @@ public void setup(String influxdbUrl, String influxDBToken) throws Exception {
                 .disableCookieManagement()
                 .disableConnectionState()
                 .build();
-        url = new URL(influxdbUrl);
+        url = URI.create(influxdbUrl).toURL();
         token = influxDBToken;
         httpRequest = createRequest(url, token);
         httpClient.start();

src/components/src/test/java/org/apache/jmeter/assertions/ResponseAssertionTest.java

@@ -25,6 +25,7 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.net.MalformedURLException;
+import java.net.URI;
 import java.net.URL;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -55,7 +56,7 @@ public void setUp() throws MalformedURLException {
         jmctx.setVariables(vars);
         jmctx.setPreviousResult(sample);
         sample.setResponseData("response Data\nline 2\n\nEOF", null);
-        sample.setURL(new URL("http://localhost/Sampler/Data/"));
+        sample.setURL(URI.create("http://localhost/Sampler/Data/").toURL());
         sample.setResponseCode("401");
         sample.setResponseHeaders("X-Header: abcd");
         sample.setRequestHeaders("X-reqHeader: cdef");

src/components/src/test/java/org/apache/jmeter/extractor/TestRegexExtractor.java

@@ -24,6 +24,7 @@
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import java.net.URI;
 import java.net.URL;
 
 import org.apache.jmeter.samplers.SampleResult;
@@ -314,7 +315,7 @@ public void testVariableExtraction8() throws Exception {
         assertTrue(extractor.useUrl(), "useURL should be true");
         extractor.process();
         assertNull(vars.get("regVal"));
-        result.setURL(new URL("http://jakarta.apache.org/index.html?abcd"));
+        result.setURL(URI.create("http://jakarta.apache.org/index.html?abcd").toURL());
         extractor.process();
         assertEquals("index", vars.get("regVal"));
     }

src/core/src/main/java/org/apache/jmeter/JMeter.java

@@ -382,7 +382,7 @@ public void start(String[] args) {
 
             Thread.setDefaultUncaughtExceptionHandler(
                     (Thread t, Throwable e) -> {
-                    if (!(e instanceof ThreadDeath)) {
+                    if (!(e instanceof VirtualMachineError)) {
                         log.error("Uncaught exception in thread {}", t, e);
                         System.err.println("Uncaught Exception " + e + " in thread " + t + ". See log file for details.");//NOSONAR
                     }

src/core/src/main/java/org/apache/jmeter/engine/StandardJMeterEngine.java

@@ -30,11 +30,11 @@
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
-import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
-import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.ReentrantLock;
 
 import org.apache.jmeter.JMeter;
 import org.apache.jmeter.samplers.SampleEvent;
@@ -92,19 +92,17 @@ public class StandardJMeterEngine implements JMeterEngine, Runnable {
     /** Whether to call System.exit(0) unconditionally at end of non-GUI test */
     private static final boolean SYSTEM_EXIT_FORCED = JMeterUtils.getPropDefault("jmeterengine.force.system.exit", false);
 
-    private static final AtomicInteger THREAD_COUNTER = new AtomicInteger(0);
-
     /**
      * Executor service to execute management tasks like "start test", "stop test".
-     * The use of {@link ExecutorService} allows propagating the exception from the threads.
-     * Thread keepalive time is set to 1 second, so threads are released early,
-     * so the application can shut down faster.
+     * Uses platform threads to keep the JVM alive while tests run
+     * (virtual threads are daemon threads and would allow premature JVM exit).
      */
     private static final ExecutorService EXECUTOR_SERVICE =
-            new ThreadPoolExecutor(0, Integer.MAX_VALUE,
-                    1L, TimeUnit.SECONDS,
-                    new java.util.concurrent.SynchronousQueue<>(),
-                    (runnable) -> new Thread(runnable, "StandardJMeterEngine-" + THREAD_COUNTER.incrementAndGet()));
+            Executors.newThreadPerTaskExecutor(
+                    Thread.ofPlatform().name("StandardJMeterEngine-", 1).factory());
+
+    private static final ReentrantLock REGISTER_LOCK = new ReentrantLock();
+    private final ReentrantLock stopTestLock = new ReentrantLock();
 
     private volatile Future<?> runningTest;
 
@@ -156,8 +154,13 @@ public static void stopEngine() {
         }
     }
 
-    public static synchronized void register(TestStateListener tl) {
-        testList.add(tl);
+    public static void register(TestStateListener tl) {
+        REGISTER_LOCK.lock();
+        try {
+            testList.add(tl);
+        } finally {
+            REGISTER_LOCK.unlock();
+        }
     }
 
     public static boolean stopThread(String threadName) {
@@ -296,14 +299,19 @@ public void reset() {
      * Stop Test Now
      */
     @Override
-    public synchronized void stopTest() {
+    public void stopTest() {
         stopTest(true);
     }
 
     @Override
     @SuppressWarnings("FutureReturnValueIgnored")
-    public synchronized void stopTest(boolean now) {
-        EXECUTOR_SERVICE.submit(new StopTest(now));
+    public void stopTest(boolean now) {
+        stopTestLock.lock();
+        try {
+            EXECUTOR_SERVICE.submit(new StopTest(now));
+        } finally {
+            stopTestLock.unlock();
+        }
     }
 
     private class StopTest implements Runnable {

src/core/src/main/java/org/apache/jmeter/gui/AbstractJMeterGuiComponent.java

@@ -388,7 +388,7 @@ public String getStaticLabel() {
     @Override
     public String getDocAnchor() {
         // Ensure we use default bundle
-        String label =  JMeterUtils.getResString(getLabelResource(), new Locale("",""));
+        String label =  JMeterUtils.getResString(getLabelResource(), Locale.ROOT);
         return label.replace(' ', '_');
     }
 

src/core/src/main/java/org/apache/jmeter/gui/action/ChangeLanguage.java

@@ -53,9 +53,9 @@ public void doActionAfterCheck(ActionEvent e) {
 
         int sep = locale.indexOf('_');
         if (sep > 0) {
-            loc = new Locale(locale.substring(0, sep), locale.substring(sep + 1));
+            loc = Locale.of(locale.substring(0, sep), locale.substring(sep + 1));
         } else {
-            loc = new Locale(locale, "");
+            loc = Locale.of(locale);
         }
         log.debug("Changing locale to {}", loc);
         try {

src/core/src/main/java/org/apache/jmeter/testbeans/gui/TestBeanGUI.java

@@ -490,7 +490,7 @@ public void localeChanged(LocaleChangeEvent event) {
     public String getDocAnchor() {
         ResourceBundle resourceBundle = ResourceBundle.getBundle(
                 testBeanClass.getName() + "Resources",  // $NON-NLS-1$
-                new Locale("",""));
+                Locale.ROOT);
 
         String name = resourceBundle.getString("displayName");
         return name.replace(' ', '_');

src/core/src/main/java/org/apache/jmeter/threads/AbstractThreadGroup.java

@@ -21,6 +21,7 @@
 import java.time.Duration;
 import java.util.IdentityHashMap;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.ReentrantLock;
 
 import org.apache.jmeter.control.Controller;
 import org.apache.jmeter.control.IteratingController;
@@ -50,6 +51,7 @@ public abstract class AbstractThreadGroup extends AbstractTestElement
 
     // Only create the map if it is required
     private final transient IdentityHashMap<TestElement, Object> children = new IdentityHashMap<>();
+    private final transient ReentrantLock childrenLock = new ReentrantLock();
 
     private static final Object DUMMY = new Object();
 
@@ -166,11 +168,14 @@ public void addTestElement(TestElement child) {
      */
     @Override
     public final boolean addTestElementOnce(TestElement child){
-        synchronized (children) {
+        childrenLock.lock();
+        try {
             if (children.putIfAbsent(child, DUMMY) == null) {
                 addTestElement(child);
                 return true;
             }
+        } finally {
+            childrenLock.unlock();
         }
         return false;
     }

src/core/src/main/java/org/apache/jmeter/threads/JMeterContextService.java

@@ -19,6 +19,7 @@
 
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.locks.ReentrantLock;
 
 import org.apache.jmeter.util.JMeterUtils;
 
@@ -39,6 +40,7 @@ public final class JMeterContextService {
 
     private static final AtomicInteger TOTAL_THREADS = new AtomicInteger();
 
+    private static final ReentrantLock TEST_LIFECYCLE_LOCK = new ReentrantLock();
     private static UnmodifiableJMeterVariables variables;
 
 
@@ -81,11 +83,16 @@ public static void replaceContext(JMeterContext context) {
      * Zeroes numberOfActiveThreads.
      * Saves current time in a field and in the JMeter property "TESTSTART.MS"
      */
-    public static synchronized void startTest() {
-        if (testStart.get() == 0) {
-            NUMBER_OF_ACTIVE_THREADS.set(0);
-            testStart.set(System.currentTimeMillis());
-            JMeterUtils.setProperty("TESTSTART.MS", Long.toString(testStart.get()));// $NON-NLS-1$
+    public static void startTest() {
+        TEST_LIFECYCLE_LOCK.lock();
+        try {
+            if (testStart.get() == 0) {
+                NUMBER_OF_ACTIVE_THREADS.set(0);
+                testStart.set(System.currentTimeMillis());
+                JMeterUtils.setProperty("TESTSTART.MS", Long.toString(testStart.get()));// $NON-NLS-1$
+            }
+        } finally {
+            TEST_LIFECYCLE_LOCK.unlock();
         }
     }
 
@@ -122,9 +129,14 @@ public static ThreadCounts getThreadCounts() {
      * Called by MainFrame#testEnded().
      * Clears start time field.
      */
-    public static synchronized void endTest() {
-        testStart.set(0);
-        resetClientSideVariables();
+    public static void endTest() {
+        TEST_LIFECYCLE_LOCK.lock();
+        try {
+            testStart.set(0);
+            resetClientSideVariables();
+        } finally {
+            TEST_LIFECYCLE_LOCK.unlock();
+        }
     }
 
     public static long getTestStartTime() {

src/core/src/main/java/org/apache/jmeter/threads/JMeterThread.java

@@ -326,8 +326,6 @@ public void run() {
             }
         } catch (Exception | JMeterError e) {
             log.error("Test failed!", e);
-        } catch (ThreadDeath e) {
-            throw e; // Must not ignore this one
         } finally {
             currentSamplerForInterruption = null; // prevent any further interrupts
             interruptLock.lock();  // make sure current interrupt is finished, prevent another starting yet

src/core/src/main/java/org/apache/jmeter/threads/TestCompiler.java

@@ -24,6 +24,7 @@
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Set;
+import java.util.concurrent.locks.ReentrantLock;
 
 import org.apache.jmeter.assertions.Assertion;
 import org.apache.jmeter.config.ConfigTestElement;
@@ -64,6 +65,7 @@ public class TestCompiler implements HashTreeTraverser {
      * Otherwise, the child is added to the parent and the pair is added to the Set.
      */
     private static final Set<ObjectPair> PAIRING = new HashSet<>();
+    private static final ReentrantLock PAIRING_LOCK = new ReentrantLock();
 
     // TODO: replace with ArrayDequeue
     private final LinkedList<TestElement> stack = new LinkedList<>();
@@ -84,9 +86,12 @@ public TestCompiler(HashTree testTree) {
      * test run.
      */
     public static void initialize() {
-        // synch is probably not needed as only called before run starts
-        synchronized (PAIRING) {
+        // lock is probably not needed as only called before run starts
+        PAIRING_LOCK.lock();
+        try {
             PAIRING.clear();
+        } finally {
+            PAIRING_LOCK.unlock();
         }
     }
 
@@ -152,13 +157,16 @@ else if(child instanceof TransactionController transactionController) {
                     duplicate = !te.addTestElementOnce(child);
                 } else { // this is only possible for 3rd party controllers by default
                     ObjectPair pair = new ObjectPair(child, parent);
-                    synchronized (PAIRING) {// Called from multiple threads
+                    PAIRING_LOCK.lock();
+                    try { // Called from multiple threads
                         if (!PAIRING.contains(pair)) {
                             parent.addTestElement(child);
                             PAIRING.add(pair);
                         } else {
                             duplicate = true;
                         }
+                    } finally {
+                        PAIRING_LOCK.unlock();
                     }
                 }
             }