fix: 修复工作流同步执行并发监听异常

- 使用写时复制集合保证事件分发期间安全增删监听器

- 按工作流实例路由同步结果并补充并发回归测试

easy-agents-flow/src/main/java/com/easyagents/flow/core/chain/EventManager.java

@@ -20,23 +20,31 @@ import com.easyagents.flow.core.chain.listener.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.*;
+import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
 
+/**
+ * 管理工作流执行过程中的事件、输出及错误监听器。
+ *
+ * <p>监听器的注册与移除频率远低于事件分发频率，使用写时复制集合保证分发过程可以无锁遍历，
+ * 同时允许其他线程安全地注册或移除监听器。</p>
+ */
 public class EventManager {
 
     private static final Logger log = LoggerFactory.getLogger(EventManager.class);
 
     protected final Map<Class<?>, List<ChainEventListener>> eventListeners = new ConcurrentHashMap<>();
-    protected final List<ChainOutputListener> outputListeners = Collections.synchronizedList(new ArrayList<>());
+    protected final List<ChainOutputListener> outputListeners = new CopyOnWriteArrayList<>();
-    protected final List<ChainErrorListener> chainErrorListeners = Collections.synchronizedList(new ArrayList<>());
+    protected final List<ChainErrorListener> chainErrorListeners = new CopyOnWriteArrayList<>();
-    protected final List<NodeErrorListener> nodeErrorListeners = Collections.synchronizedList(new ArrayList<>());
+    protected final List<NodeErrorListener> nodeErrorListeners = new CopyOnWriteArrayList<>();
 
     /**
      * ---------- 通用事件监听器 ----------
      */
     public void addEventListener(Class<? extends Event> eventClass, ChainEventListener listener) {
-        eventListeners.computeIfAbsent(eventClass, k -> Collections.synchronizedList(new ArrayList<>())).add(listener);
+        eventListeners.computeIfAbsent(eventClass, key -> new CopyOnWriteArrayList<>()).add(listener);
     }
 
     public void addEventListener(ChainEventListener listener) {

easy-agents-flow/src/main/java/com/easyagents/flow/core/chain/runtime/ChainExecutor.java

@@ -44,6 +44,9 @@ public class ChainExecutor {
     private final NodeStateRepository nodeStateRepository;
     private final TriggerScheduler triggerScheduler;
     private final EventManager eventManager = new EventManager();
+    /** 等待同步执行结果的任务，按工作流实例 ID 进行常量时间路由。 */
+    private final ConcurrentMap<String, CompletableFuture<Map<String, Object>>> pendingExecutions =
+            new ConcurrentHashMap<>();
 
     public ChainExecutor(ChainDefinitionRepository definitionRepository
             , ChainStateRepository chainStateRepository
@@ -53,7 +56,7 @@ public class ChainExecutor {
         this.chainStateRepository = chainStateRepository;
         this.nodeStateRepository = nodeStateRepository;
         this.triggerScheduler = ChainRuntime.triggerScheduler();
-        this.triggerScheduler.registerConsumer(this::accept);
+        registerRuntimeCallbacks();
     }
 
 
@@ -65,7 +68,7 @@ public class ChainExecutor {
         this.chainStateRepository = chainStateRepository;
         this.nodeStateRepository = nodeStateRepository;
         this.triggerScheduler = triggerScheduler;
-        this.triggerScheduler.registerConsumer(this::accept);
+        registerRuntimeCallbacks();
     }
 
 
@@ -79,26 +82,12 @@ public class ChainExecutor {
         String stateInstanceId = chain.getStateInstanceId();
         CompletableFuture<Map<String, Object>> future = new CompletableFuture<>();
 
-        ChainEventListener listener = (event, c) -> {
+        CompletableFuture<Map<String, Object>> existing = pendingExecutions.putIfAbsent(stateInstanceId, future);
-            if (event instanceof ChainStatusChangeEvent) {
+        if (existing != null) {
-                if (((ChainStatusChangeEvent) event).getStatus().isTerminal()
+            throw new IllegalStateException("Duplicate pending chain execution: " + stateInstanceId);
-                        && c.getStateInstanceId().equals(stateInstanceId)) {
-                    ChainState state = chainStateRepository.load(stateInstanceId);
-                    Map<String, Object> execResult = state.getExecuteResult();
-                    future.complete(execResult != null ? execResult : Collections.emptyMap());
         }
-            }
-        };
-
-        ChainErrorListener errorListener = (error, c) -> {
-            if (c.getStateInstanceId().equals(stateInstanceId)) {
-                future.completeExceptionally(error);
-            }
-        };
 
         try {
-            this.addEventListener(listener);
-            this.addErrorListener(errorListener);
             chain.start(variables);
             Map<String, Object> result = future.get(timeout, unit);
             clearDefaultStates(result);
@@ -114,8 +103,59 @@ public class ChainExecutor {
             future.cancel(true);
             throw new RuntimeException("Execution failed", e.getCause());
         } finally {
-            this.removeEventListener(listener);
+            pendingExecutions.remove(stateInstanceId, future);
-            this.removeErrorListener(errorListener);
+        }
+    }
+
+    /**
+     * 注册工作流调度和同步结果路由回调。
+     */
+    private void registerRuntimeCallbacks() {
+        eventManager.addEventListener(ChainStatusChangeEvent.class, this::completePendingExecution);
+        eventManager.addChainErrorListener(this::failPendingExecution);
+        triggerScheduler.registerConsumer(this::accept);
+    }
+
+    /**
+     * 在工作流进入终态时完成对应的同步等待任务。
+     *
+     * @param event 工作流状态事件
+     * @param chain 产生事件的工作流实例
+     */
+    private void completePendingExecution(Event event, Chain chain) {
+        if (!(event instanceof ChainStatusChangeEvent statusChangeEvent)
+                || !statusChangeEvent.getStatus().isTerminal()) {
+            return;
+        }
+
+        String stateInstanceId = chain.getStateInstanceId();
+        CompletableFuture<Map<String, Object>> future = pendingExecutions.get(stateInstanceId);
+        if (future == null) {
+            return;
+        }
+
+        try {
+            ChainState state = chainStateRepository.load(stateInstanceId);
+            if (state == null) {
+                throw new ChainException("Chain state not found: " + stateInstanceId);
+            }
+            Map<String, Object> execResult = state.getExecuteResult();
+            future.complete(execResult != null ? execResult : Collections.emptyMap());
+        } catch (Exception error) {
+            future.completeExceptionally(error);
+        }
+    }
+
+    /**
+     * 将工作流执行异常传递给对应的同步等待任务。
+     *
+     * @param error 工作流执行异常
+     * @param chain 发生异常的工作流实例
+     */
+    private void failPendingExecution(Throwable error, Chain chain) {
+        CompletableFuture<Map<String, Object>> future = pendingExecutions.get(chain.getStateInstanceId());
+        if (future != null) {
+            future.completeExceptionally(error);
         }
     }
 

easy-agents-flow/src/test/java/com/easyagents/flow/core/test/ChainExecutorConcurrencyTest.java

@@ -0,0 +1,112 @@
+/**
+ * Copyright (c) 2025-2026, Michael Yang 杨福海 (fuhai999@gmail.com).
+ * <p>
+ * Licensed under the GNU Lesser General Public License (LGPL) ,Version 3.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * http://www.gnu.org/licenses/lgpl-3.0.txt
+ * <p>
+ * 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.easyagents.flow.core.test;
+
+import com.easyagents.flow.core.chain.ChainDefinition;
+import com.easyagents.flow.core.chain.Edge;
+import com.easyagents.flow.core.chain.repository.InMemoryChainStateRepository;
+import com.easyagents.flow.core.chain.repository.InMemoryNodeStateRepository;
+import com.easyagents.flow.core.chain.runtime.ChainExecutor;
+import com.easyagents.flow.core.chain.runtime.InMemoryTriggerStore;
+import com.easyagents.flow.core.chain.runtime.TriggerScheduler;
+import com.easyagents.flow.core.node.EndNode;
+import com.easyagents.flow.core.node.StartNode;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * {@link ChainExecutor} 并发同步执行测试。
+ */
+public class ChainExecutorConcurrencyTest {
+
+    /**
+     * 验证多个同步调用可以通过实例 ID 独立接收执行结果。
+     *
+     * @throws Exception 并发任务执行失败、超时或中断时抛出
+     */
+    @Test
+    public void shouldRouteConcurrentSynchronousExecutionResults() throws Exception {
+        ScheduledExecutorService schedulerPool = Executors.newScheduledThreadPool(2);
+        ExecutorService workerPool = Executors.newFixedThreadPool(8);
+        ExecutorService callerPool = Executors.newFixedThreadPool(8);
+        TriggerScheduler triggerScheduler = new TriggerScheduler(
+                new InMemoryTriggerStore(), schedulerPool, workerPool, 1000L);
+        ChainDefinition definition = createDefinition();
+        ChainExecutor chainExecutor = new ChainExecutor(
+                id -> definition,
+                new InMemoryChainStateRepository(),
+                new InMemoryNodeStateRepository(),
+                triggerScheduler);
+
+        int executionCount = 16;
+        CountDownLatch startGate = new CountDownLatch(1);
+        List<Future<Map<String, Object>>> executions = new ArrayList<>(executionCount);
+
+        try {
+            for (int index = 0; index < executionCount; index++) {
+                executions.add(callerPool.submit(() -> {
+                    startGate.await();
+                    return chainExecutor.execute(definition.getId(), Collections.emptyMap());
+                }));
+            }
+            startGate.countDown();
+
+            for (Future<Map<String, Object>> execution : executions) {
+                Assert.assertNotNull(execution.get(10, TimeUnit.SECONDS));
+            }
+        } finally {
+            startGate.countDown();
+            callerPool.shutdownNow();
+            triggerScheduler.shutdown();
+        }
+    }
+
+    /**
+     * 创建仅包含开始和结束节点的测试工作流。
+     *
+     * @return 测试工作流定义
+     */
+    private ChainDefinition createDefinition() {
+        ChainDefinition definition = new ChainDefinition();
+        definition.setId("concurrent-sync-test");
+
+        StartNode startNode = new StartNode();
+        startNode.setId("start");
+        EndNode endNode = new EndNode();
+        endNode.setId("end");
+
+        Edge edge = new Edge();
+        edge.setId("start-to-end");
+        edge.setSource(startNode.getId());
+        edge.setTarget(endNode.getId());
+
+        definition.addNode(startNode);
+        definition.addNode(endNode);
+        definition.addEdge(edge);
+        return definition;
+    }
+}

easy-agents-flow/src/test/java/com/easyagents/flow/core/test/EventManagerConcurrencyTest.java

@@ -0,0 +1,91 @@
+/**
+ * Copyright (c) 2025-2026, Michael Yang 杨福海 (fuhai999@gmail.com).
+ * <p>
+ * Licensed under the GNU Lesser General Public License (LGPL) ,Version 3.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * http://www.gnu.org/licenses/lgpl-3.0.txt
+ * <p>
+ * 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.easyagents.flow.core.test;
+
+import com.easyagents.flow.core.chain.EventManager;
+import com.easyagents.flow.core.chain.event.ChainEndEvent;
+import com.easyagents.flow.core.chain.listener.ChainEventListener;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * {@link EventManager} 并发行为测试。
+ */
+public class EventManagerConcurrencyTest {
+
+    /**
+     * 验证事件分发期间可以从其他线程移除监听器，当前分发使用稳定快照，后续分发不再调用已移除监听器。
+     *
+     * @throws Exception 等待测试线程超时或中断时抛出
+     */
+    @Test
+    public void shouldAllowListenerRemovalDuringEventDispatch() throws Exception {
+        EventManager eventManager = new EventManager();
+        CountDownLatch dispatchStarted = new CountDownLatch(1);
+        CountDownLatch continueDispatch = new CountDownLatch(1);
+        AtomicInteger retainedInvocationCount = new AtomicInteger();
+        AtomicInteger removedInvocationCount = new AtomicInteger();
+        AtomicReference<Throwable> dispatchFailure = new AtomicReference<>();
+
+        ChainEventListener blockingListener = (event, chain) -> {
+            dispatchStarted.countDown();
+            try {
+                if (!continueDispatch.await(3, TimeUnit.SECONDS)) {
+                    throw new AssertionError("事件分发等待超时");
+                }
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                throw new AssertionError("事件分发线程被中断", e);
+            }
+        };
+        ChainEventListener retainedListener = (event, chain) -> retainedInvocationCount.incrementAndGet();
+        ChainEventListener removedListener = (event, chain) -> removedInvocationCount.incrementAndGet();
+        eventManager.addEventListener(blockingListener);
+        eventManager.addEventListener(retainedListener);
+        eventManager.addEventListener(removedListener);
+
+        Thread dispatchThread = new Thread(() -> {
+            try {
+                eventManager.notifyEvent(new ChainEndEvent(null), null);
+            } catch (Throwable error) {
+                dispatchFailure.set(error);
+            }
+        }, "event-manager-dispatch-test");
+        dispatchThread.start();
+
+        try {
+            Assert.assertTrue("事件分发应在测试超时前开始", dispatchStarted.await(3, TimeUnit.SECONDS));
+            eventManager.removeEventListener(removedListener);
+        } finally {
+            continueDispatch.countDown();
+        }
+
+        dispatchThread.join(3000L);
+        Assert.assertFalse("事件分发线程应正常结束", dispatchThread.isAlive());
+        Assert.assertNull("并发移除监听器不应中断事件分发", dispatchFailure.get());
+        Assert.assertEquals(1, retainedInvocationCount.get());
+        Assert.assertEquals("当前事件应按分发开始时的快照通知", 1, removedInvocationCount.get());
+
+        eventManager.notifyEvent(new ChainEndEvent(null), null);
+        Assert.assertEquals(2, retainedInvocationCount.get());
+        Assert.assertEquals("后续事件不应通知已移除监听器", 1, removedInvocationCount.get());
+    }
+}