Fixes issue #24843 log a warning in the rare case the Resource handle

appserver/connectors/connectors-runtime/src/main/java/com/sun/enterprise/connectors/ConnectorRuntime.java

@@ -234,8 +234,9 @@ public class ConnectorRuntime implements com.sun.appserv.connectors.internal.api
     @Inject
     private Provider<ResourceManager> resourceManagerProvider;
 
+    /* protected for unit test */
     @Inject
-    private ProcessEnvironment processEnvironment;
+    protected ProcessEnvironment processEnvironment;
 
     @Inject
     private DriverLoader driverLoader;

appserver/connectors/connectors-runtime/src/main/java/com/sun/enterprise/resource/pool/ConnectionPool.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, 2023 Contributors to the Eclipse Foundation
+ * Copyright (c) 2022, 2024 Contributors to the Eclipse Foundation
  * Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
  *
  * This program and the accompanying materials are made available under the
@@ -946,7 +946,11 @@ public void resourceClosed(ResourceHandle handle) throws IllegalStateException {
         }
 
         if (!state.isBusy()) {
-            throw new IllegalStateException("state.isBusy() : false");
+            // Do not throw exception, the current transaction should not fail if the state is already 'free'.
+            // This method is for example also called from putbackBadResourceToPool, which also
+            // does not throw the IllegalStateException anymore.
+            // throw new IllegalStateException("state.isBusy() : false");
+            LOG.log(WARNING, "resourceClosed - Expecting 'state.isBusy() : false', but was true for handle: " + handle);
         }
 
         // mark as not busy
@@ -1051,6 +1055,10 @@ public void resourceErrorOccurred(ResourceHandle resourceHandle) throws IllegalS
             throw new IllegalStateException();
         }
 
+        // mark as not busy
+        setResourceStateToFree(resourceHandle);
+        state.touchTimestamp();
+
         // changed order of commands
 
         // Commenting resources.remove() out since we will call an iter.remove()

appserver/connectors/connectors-runtime/src/test/java/com/sun/enterprise/resource/pool/ConnectionPoolTest.java

@@ -0,0 +1,332 @@
+/*
+ * Copyright (c) 2024 Eclipse Foundation and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the
+ * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+ * version 2 with the GNU Classpath Exception, which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ */
+
+package com.sun.enterprise.resource.pool;
+
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.createNiceMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.isNull;
+import static org.easymock.EasyMock.notNull;
+import static org.easymock.EasyMock.replay;
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.ArrayList;
+import java.util.Hashtable;
+import java.util.List;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+
+import org.easymock.IExpectationSetters;
+import org.glassfish.api.admin.ProcessEnvironment;
+import org.glassfish.api.naming.SimpleJndiName;
+import org.glassfish.internal.api.DelegatingClassLoader;
+import org.glassfish.resourcebase.resources.api.PoolInfo;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
+import org.opentest4j.MultipleFailuresError;
+
+import com.sun.appserv.connectors.internal.api.ConnectorRuntimeException;
+import com.sun.appserv.connectors.internal.api.PoolingException;
+import com.sun.enterprise.connectors.ConnectorConnectionPool;
+import com.sun.enterprise.connectors.ConnectorRuntime;
+import com.sun.enterprise.connectors.util.ConnectionPoolObjectsUtils;
+import com.sun.enterprise.deployment.ConnectorDescriptor;
+import com.sun.enterprise.resource.ResourceHandle;
+import com.sun.enterprise.resource.ResourceSpec;
+import com.sun.enterprise.resource.ResourceState;
+import com.sun.enterprise.resource.allocator.LocalTxConnectorAllocator;
+import com.sun.enterprise.resource.allocator.ResourceAllocator;
+import com.sun.enterprise.resource.pool.datastructure.RWLockDataStructure;
+import com.sun.enterprise.transaction.api.JavaEETransaction;
+
+import jakarta.resource.ResourceException;
+import jakarta.resource.spi.ManagedConnection;
+import jakarta.resource.spi.ManagedConnectionFactory;
+import jakarta.transaction.Transaction;
+
+public class ConnectionPoolTest {
+
+    private ManagedConnection managedConnection;
+    private ManagedConnectionFactory managedConnectionFactory;
+    private JavaEETransaction javaEETransaction;
+
+    private ConnectionPool connectionPool;
+
+    private ResourceSpec resourceSpec;
+
+    @BeforeEach
+    public void createAndPopulateMocks() throws PoolingException, ResourceException {
+        List<Object> mocks = new ArrayList<>();
+
+        // Mock ManagedConnection
+        managedConnection = createNiceMock(ManagedConnection.class);
+        mocks.add(managedConnection);
+
+        // Mock ManagedConnectionFactory
+        ManagedConnectionFactory localConnectionFactory = createMock(ManagedConnectionFactory.class);
+        IExpectationSetters<ManagedConnection> createConnectionExpectation = expect(
+                localConnectionFactory.createManagedConnection(isNull(), isNull()));
+        createConnectionExpectation.andReturn(managedConnection)
+                .atLeastOnce();
+
+        // Must return a not null object in matchManagedConnections to ensure matching in the ConnectionPool is 'true'
+        IExpectationSetters<ManagedConnection> matchExpectation = expect(localConnectionFactory.matchManagedConnections(notNull(), isNull(), isNull()));
+        matchExpectation.andReturn(managedConnection)
+                .atLeastOnce();
+
+        managedConnectionFactory = localConnectionFactory;
+        mocks.add(managedConnectionFactory);
+
+        // Mock JavaEETransaction
+        javaEETransaction = createNiceMock(JavaEETransaction.class);
+        mocks.add(javaEETransaction);
+
+        replay(mocks.toArray());
+
+        // Make sure ConnectorRuntime singleton is initialized
+        MyConnectorRuntime connectorRuntime = new MyConnectorRuntime();
+        ProcessEnvironment processEnvironment = new ProcessEnvironment();
+        connectorRuntime.setProcessEnvironment(processEnvironment);
+        connectorRuntime.postConstruct();
+    }
+
+    private void createConnectionPool(int maxPoolSize) throws PoolingException {
+        PoolInfo poolInfo = ConnectionPoolTest.getPoolInfo();
+        MyConnectionPool.myMaxPoolSize = maxPoolSize;
+        connectionPool = new MyConnectionPool(poolInfo);
+        assertEquals(1, connectionPool.getSteadyPoolSize());
+        assertEquals(maxPoolSize, connectionPool.getMaxPoolSize());
+
+        resourceSpec = new ResourceSpec(new SimpleJndiName("myResourceSpec"), ResourceSpec.JNDI_NAME);
+        resourceSpec.setPoolInfo(poolInfo);
+    }
+
+    /**
+     * Basic test to show ConnectionPool can be instantiated in a unit test
+     */
+    @Test
+    void basicConnectionPoolTest() throws Exception {
+        createConnectionPool(2);
+
+        ResourceAllocator alloc = new LocalTxConnectorAllocator(null, managedConnectionFactory, resourceSpec, null,
+                null, null, null, false);
+        Transaction transaction = javaEETransaction;
+
+        // Test how many resources are available
+        // Expect 0 because the pool is not initialized yet. It will be initialized when the first resource is requested
+        assertResourcesSize(0);
+
+        // Test getting 3 resources from the pool of 2
+        ResourceHandle resource1 = connectionPool.getResource(resourceSpec, alloc, transaction);
+        assertNotNull(resource1);
+        assertResourceIsBusy(resource1);
+        assertResourcesSize(1);
+
+        ResourceHandle resource2 = connectionPool.getResource(resourceSpec, alloc, transaction);
+        assertNotNull(resource2);
+        assertResourceIsBusy(resource2);
+        assertResourcesSize(2);
+
+        assertThrows(PoolingException.class, () -> {
+            connectionPool.getResource(resourceSpec, alloc, transaction);
+        });
+
+        // Test returning 2 resources to the pool
+        connectionPool.resourceClosed(resource2);
+        assertResourceIsNotBusy(resource2);
+
+        // Test issue #24843: make the state of resource1 not busy anymore (it should not happen but it happens in rare cases),
+        // resource should still be closed without throwing an exception.
+        resource1.getResourceState().setBusy(false);
+        connectionPool.resourceClosed(resource1);
+        assertResourceIsNotBusy(resource1);
+
+        // Test how many resources are available
+        assertResourcesSize(2);
+
+        connectionPool.emptyPool();
+        assertResourcesSize(0);
+    }
+
+    @Test
+    @Timeout(value = 10)
+    void basicConnectionPoolMultiThreadedTest() throws Exception {
+        int maxConnectionPoolSize = 30;
+        createConnectionPool(maxConnectionPoolSize);
+
+        ResourceAllocator alloc = new LocalTxConnectorAllocator(null, managedConnectionFactory, resourceSpec, null,
+                null, null, null, false);
+
+        int taskCount = 100;
+        List<Callable<Void>> tasks = new ArrayList<>(taskCount);
+        for (int i = 0; i < taskCount; i++) {
+            tasks.add(() -> {
+                while (true) {
+                    try {
+                        // Get resource
+                        ResourceHandle resource = connectionPool.getResource(resourceSpec, alloc, javaEETransaction);
+                        assertNotNull(resource);
+                        assertResourceIsBusy(resource);
+
+                        // Keep resource a bit occupied, to ensure more than 1 resource from the
+                        // pool is used at the same time
+                        Thread.sleep(0, 10);
+                        // Return resource
+                        connectionPool.resourceClosed(resource);
+                        assertResourceIsNotBusy(resource);
+                        return null;
+                    } catch (PoolingException e) {
+                        // Try again a bit later, should get a connection at one point
+                        Thread.sleep(0, 5);
+                    }
+                }
+            });
+        }
+        runTheTasks(tasks);
+        assertResourcesSize(maxConnectionPoolSize);
+        connectionPool.emptyPool();
+        assertResourcesSize(0);
+    }
+
+    @Test
+    @Timeout(value = 10)
+    void resourceErrorOccurredMultiThreadedTest() throws Exception {
+        int maxConnectionPoolSize = 30;
+        createConnectionPool(maxConnectionPoolSize);
+
+        ResourceAllocator alloc = new LocalTxConnectorAllocator(null, managedConnectionFactory, resourceSpec, null,
+                null, null, null, false);
+
+        int taskCount = 100;
+        List<Callable<Void>> tasks = new ArrayList<>(taskCount);
+        for (int i = 0; i < taskCount; i++) {
+            tasks.add(() -> {
+                while (true) {
+                    try {
+                        // Get resource
+                        ResourceHandle resource = connectionPool.getResource(resourceSpec, alloc, javaEETransaction);
+                        assertNotNull(resource);
+                        assertResourceIsBusy(resource);
+
+                        // Keep resource a bit occupied, to ensure more than 1 resource from the
+                        // pool is used at the same time
+                        Thread.sleep(0, 10);
+                        // Return resource
+                        connectionPool.resourceErrorOccurred(resource);
+                        assertResourceIsNotBusy(resource);
+                        return null;
+                    } catch (PoolingException e) {
+                        // Try again a bit later, should get a connection at one point
+                        Thread.sleep(0, 5);
+                    }
+                }
+            });
+        }
+        runTheTasks(tasks);
+
+        connectionPool.emptyPool();
+        assertResourcesSize(0);
+    }
+
+    private void runTheTasks(List<Callable<Void>> tasks) throws InterruptedException, MultipleFailuresError {
+        ExecutorService threadPool = Executors.newFixedThreadPool(1000);
+        List<Future<Void>> futures = threadPool.invokeAll(tasks, 10, TimeUnit.SECONDS);
+        assertAll(
+                () -> assertTrue(futures.stream().allMatch(f -> f.isDone()), "All done."),
+                () -> assertFalse(futures.stream().anyMatch(f -> f.isCancelled()), "None cancelled."));
+    }
+
+    private void assertResourceIsBusy(ResourceHandle resource) {
+        // Resource must be marked as isBusy right after call to getResource
+        ResourceState resourceState = resource.getResourceState();
+        assertTrue(resourceState.isBusy());
+        assertFalse(resourceState.isFree());
+    }
+
+    private void assertResourceIsNotBusy(ResourceHandle resource) {
+        // Resource must be marked as not isBusy / isFree right after call to resourceClosed
+        ResourceState resourceState = resource.getResourceState();
+        assertTrue(resourceState.isFree());
+        assertFalse(resourceState.isBusy());
+    }
+
+    private void assertResourcesSize(int expectedSize) {
+        RWLockDataStructure dataStructure = (RWLockDataStructure) connectionPool.dataStructure;
+        assertEquals(expectedSize, dataStructure.getResourcesSize());
+        assertEquals(expectedSize, dataStructure.getAllResources()
+                .size());
+    }
+
+    public static class MyConnectionPool extends ConnectionPool {
+
+        public static int myMaxPoolSize;
+
+        public MyConnectionPool(PoolInfo poolInfo) throws PoolingException {
+            super(ConnectionPoolTest.getPoolInfo(), new Hashtable<>());
+        }
+
+        @Override
+        protected ConnectorConnectionPool getPoolConfigurationFromJndi(Hashtable env) throws PoolingException {
+            ConnectorConnectionPool connectorConnectionPool = ConnectionPoolObjectsUtils
+                    .createDefaultConnectorPoolObject(poolInfo, null);
+
+            // lower the default pool size
+            connectorConnectionPool.setSteadyPoolSize("1");
+            connectorConnectionPool.setMaxPoolSize("" + myMaxPoolSize);
+
+            return connectorConnectionPool;
+        }
+    }
+
+    public class MyConnectorRuntime extends ConnectorRuntime {
+
+        public void setProcessEnvironment(ProcessEnvironment processEnvironment) {
+            this.processEnvironment = processEnvironment;
+        }
+
+        @Override
+        public PoolType getPoolType(PoolInfo poolInfo) throws ConnectorRuntimeException {
+            return PoolType.STANDARD_POOL;
+        }
+
+        @Override
+        public ConnectorDescriptor getConnectorDescriptor(String rarName) throws ConnectorRuntimeException {
+            throw new ConnectorRuntimeException("No rar in unit test");
+        }
+
+        @Override
+        public DelegatingClassLoader getConnectorClassLoader() {
+            // Return null, system classloader will be used
+            return null;
+        }
+    }
+
+    private static PoolInfo getPoolInfo() {
+        SimpleJndiName jndiName = new SimpleJndiName("myPool");
+        return new PoolInfo(jndiName);
+    }
+
+}