Introduce a simple deterministic reproducer

JAVA-5516

Author: stIncMale

driver-core/src/test/functional/com/mongodb/internal/operation/AsyncCommandBatchCursorFunctionalTest.java

@@ -45,7 +45,6 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.ForkJoinPool;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
@@ -300,24 +299,6 @@ void testLimitWithGetMore() {
         assertTrue(cursor.isClosed());
     }
 
-    @Test
-    void attemptJava5516() {
-        BsonDocument commandResult = executeFindCommand(5, 2);
-        cursor = new AsyncCommandBatchCursor<>(commandResult, 2, 0, DOCUMENT_DECODER,
-                                               null, connectionSource, connection);
-        assertNotNull(cursorNext());
-        // Calling `close` twice is the key to reproducing.
-        // It does not matter whether we call `close` twice from the same thread or not.
-        ForkJoinPool.commonPool().execute(() -> cursor.close());
-        ForkJoinPool.commonPool().execute(() -> cursor.close());
-        try {
-            assertNotNull(cursorNext());
-            assertNotNull(cursorNext());
-        } catch (IllegalStateException e) {
-            // one of the expected outcomes, because we call `cursorNext` concurrently with `close`
-        }
-    }
-
     @Test
     @DisplayName("test limit with large documents")
     void testLimitWithLargeDocuments() {

driver-core/src/test/unit/com/mongodb/internal/operation/CursorResourceManagerTest.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2008-present MongoDB, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.mongodb.internal.operation;
+
+import com.mongodb.MongoNamespace;
+import com.mongodb.ServerCursor;
+import com.mongodb.internal.binding.AsyncConnectionSource;
+import com.mongodb.internal.binding.ReferenceCounted;
+import com.mongodb.internal.connection.Connection;
+import com.mongodb.internal.mockito.MongoMockito;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.mockito.Mockito.when;
+
+final class CursorResourceManagerTest {
+    @Test
+    void doubleCloseExecutedConcurrentlyWithOperationBeingInProgressShouldNotFail() {
+        CursorResourceManager<?, ?> cursorResourceManager = new CursorResourceManager<ReferenceCounted, ReferenceCounted>(
+                new MongoNamespace("db", "coll"),
+                MongoMockito.mock(AsyncConnectionSource.class, mock -> {
+                    when(mock.retain()).thenReturn(mock);
+                    when(mock.release()).thenReturn(1);
+                }),
+                null,
+                MongoMockito.mock(ServerCursor.class)) {
+            @Override
+            void markAsPinned(final ReferenceCounted connectionToPin, final Connection.PinningMode pinningMode) {
+            }
+
+            @Override
+            void doClose() {
+            }
+        };
+        cursorResourceManager.tryStartOperation();
+        try {
+            assertDoesNotThrow(() -> {
+                cursorResourceManager.close();
+                cursorResourceManager.close();
+                cursorResourceManager.setServerCursor(null);
+            });
+        } finally {
+            cursorResourceManager.endOperation();
+        }
+    }
+}