Fixed HttpLoadGenerator logic

- requestCounter was increased even when nothing else happened in the iteration
- countRunning changed to Semaphore

Signed-off-by: David Matějček <[email protected]>

Author: dmatej

appserver/tests/application/src/test/java/org/glassfish/main/test/app/monitoring/AppClient.java

@@ -85,8 +85,10 @@ private HttpURLConnection openHttpGetConnection(String context) {
         try {
             HttpURLConnection connection = GlassFishTestEnvironment.openConnection(port, context);
             connection.setRequestMethod("GET");
+            connection.setUseCaches(false);
             connection.setConnectTimeout(100);
             connection.setReadTimeout(requestTimeout);
+            connection.connect();
             return connection;
         } catch (IOException e) {
             throw new IllegalStateException("Failed to open connection to " + context, e);

appserver/tests/application/src/test/java/org/glassfish/main/test/app/monitoring/HttpLoadGenerator.java

@@ -22,14 +22,14 @@
 import java.util.concurrent.ConcurrentLinkedDeque;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.glassfish.main.test.app.monitoring.ThreadPoolMonitoringTest.Action;
 
 import static java.lang.System.Logger.Level.DEBUG;
 import static java.lang.System.Logger.Level.INFO;
-import static java.lang.System.Logger.Level.TRACE;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 class HttpLoadGenerator extends Thread implements AutoCloseable {
@@ -66,23 +66,27 @@ class HttpLoadGenerator extends Thread implements AutoCloseable {
 
     @Override
     public void run() {
-        final AtomicInteger countRunning = new AtomicInteger(0);
+        final Semaphore countRunning = new Semaphore(maxParallel);
         while (!isInterrupted()) {
-            if (requestCounter.getAndIncrement() > maxRequests) {
+            if (requestCounter.get() == maxRequests) {
                 LOG.log(INFO, "Already produced {0} requests, stopping the executor.", maxRequests);
                 executor.shutdown();
                 return;
             }
-            if (countRunning.get() == maxParallel) {
-                LOG.log(TRACE, "Waiting...");
-                Thread.onSpinWait();
-                continue;
+            try {
+                countRunning.acquire();
+            } catch (InterruptedException e) {
+                interrupt();
             }
-            LOG.log(DEBUG, () -> "Running: " + countRunning + ". Starting another...");
-            countRunning.incrementAndGet();
+            LOG.log(DEBUG,
+                () -> "Running: " + (maxParallel - countRunning.availablePermits()) + ". Starting another...");
+            requestCounter.incrementAndGet();
             executor.submit(() -> {
-                action.doAction();
-                countRunning.decrementAndGet();
+                try {
+                    action.doAction();
+                } finally {
+                    countRunning.release();
+                }
             });
         }
     }

appserver/tests/application/src/test/java/org/glassfish/main/test/app/monitoring/ThreadPoolMonitoringTest.java

@@ -197,13 +197,10 @@ void testDualListenerHugeAmountOfFastRequests() throws Exception {
 
         generator1.close();
         generatorTest.close();
-        waitForThreadsBusyCount(HTTP_POOL_1_PORT, 0);
-        waitForThreadsBusyCount(HTTP_POOL_TEST_PORT, 0);
         waitForTaskCountStoppedChanging(HTTP_POOL_1_PORT);
         waitForTaskCountStoppedChanging(HTTP_POOL_TEST_PORT);
-        // FIXME: Even those waits don't ensure that task count will not increase.
-        //        Reproduced on GHA, more probable on Windows machine - task count changed by a number of currentThreadCount.
-        Thread.sleep(1000L);
+        waitForThreadsBusyCount(HTTP_POOL_1_PORT, 0);
+        waitForThreadsBusyCount(HTTP_POOL_TEST_PORT, 0);
         final ThreadPoolMetrics metrics1 = getThreadPoolMetrics(HTTP_POOL_1);
         final ThreadPoolMetrics metricsTest = getThreadPoolMetrics(HTTP_POOL_TEST);
         assertAll(