CAMEL-22789: camel-core - Using bridgeErrorHandler=true can cause endless loop if triggered from onCompletion (such as camel-aws-s3) (#20476)

Author: davsclaus

core/camel-core/src/test/java/org/apache/camel/processor/DefaultConsumerUoWBridgeErrorHandlerTest.java

@@ -0,0 +1,163 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.camel.processor;
+
+import java.util.Map;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.camel.Component;
+import org.apache.camel.Consumer;
+import org.apache.camel.ContextTestSupport;
+import org.apache.camel.Endpoint;
+import org.apache.camel.Exchange;
+import org.apache.camel.Processor;
+import org.apache.camel.Producer;
+import org.apache.camel.builder.RouteBuilder;
+import org.apache.camel.support.DefaultComponent;
+import org.apache.camel.support.DefaultConsumer;
+import org.apache.camel.support.DefaultEndpoint;
+import org.apache.camel.support.SynchronizationAdapter;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+/**
+ *
+ */
+public class DefaultConsumerUoWBridgeErrorHandlerTest extends ContextTestSupport {
+
+    protected final CountDownLatch latch = new CountDownLatch(1);
+
+    @Test
+    public void testDefaultConsumerBridgeErrorHandler() throws Exception {
+        getMockEndpoint("mock:result").expectedBodiesReceived("Hello World");
+        getMockEndpoint("mock:dead").expectedBodiesReceived("Cannot complete");
+
+        latch.countDown();
+
+        assertMockEndpointsSatisfied();
+
+        Exception cause = getMockEndpoint("mock:dead").getReceivedExchanges().get(0).getProperty(Exchange.EXCEPTION_CAUGHT,
+                Exception.class);
+        assertNotNull(cause);
+        assertEquals("Forced error", cause.getMessage());
+    }
+
+    @Override
+    protected RouteBuilder createRouteBuilder() {
+        // START SNIPPET: e1
+        return new RouteBuilder() {
+            @Override
+            public void configure() {
+                // register our custom component
+                getContext().addComponent("my", new MyComponent());
+
+                // configure error handler
+                errorHandler(deadLetterChannel("mock:dead"));
+
+                // configure the consumer to bridge with the Camel error
+                // handler,
+                // so the above error handler will trigger if exceptions also
+                // occurs inside the consumer
+                from("my:foo?bridgeErrorHandler=true").to("log:foo").to("mock:result");
+            }
+        };
+        // END SNIPPET: e1
+    }
+
+    public class MyComponent extends DefaultComponent {
+
+        @Override
+        protected Endpoint createEndpoint(String uri, String remaining, Map<String, Object> parameters) {
+            return new MyEndpoint(uri, this);
+        }
+    }
+
+    public class MyEndpoint extends DefaultEndpoint {
+
+        public MyEndpoint(String endpointUri, Component component) {
+            super(endpointUri, component);
+        }
+
+        @Override
+        public Producer createProducer() {
+            return null;
+        }
+
+        @Override
+        public Consumer createConsumer(Processor processor) throws Exception {
+            Consumer answer = new MyConsumer(this, processor);
+            configureConsumer(answer);
+            return answer;
+        }
+
+        @Override
+        public boolean isSingleton() {
+            return true;
+        }
+    }
+
+    public class MyConsumer extends DefaultConsumer {
+
+        private int invoked;
+
+        public MyConsumer(Endpoint endpoint, Processor processor) {
+            super(endpoint, processor);
+        }
+
+        public void doSomething() {
+            try {
+                Exchange exchange = getEndpoint().createExchange();
+                exchange.getExchangeExtension().addOnCompletion(new SynchronizationAdapter() {
+                    @Override
+                    public void onComplete(Exchange exchange) {
+                        // trigger bridge error handler in UoW completion to test that this is not called again in endless loop
+                        getExceptionHandler().handleException("Cannot complete", exchange,
+                                new IllegalArgumentException("Forced error"));
+                    }
+                });
+                exchange.getIn().setBody("Hello World");
+                getProcessor().process(exchange);
+
+            } catch (Exception e) {
+                getExceptionHandler().handleException("Cannot process", e);
+            }
+        }
+
+        @Override
+        protected void doStart() throws Exception {
+            super.doStart();
+
+            Thread thread = new Thread() {
+                @Override
+                public void run() {
+                    try {
+                        // do not start before the mocks has been setup and is
+                        // ready
+                        latch.await(5, TimeUnit.SECONDS);
+                        doSomething();
+                    } catch (Exception e) {
+                        // ignore
+                    }
+                }
+            };
+            thread.start();
+        }
+    }
+}

core/camel-support/src/main/java/org/apache/camel/support/BridgeExceptionHandlerToErrorHandler.java

@@ -58,29 +58,36 @@ public void handleException(String message, Throwable exception) {
 
     @Override
     public void handleException(String message, Exchange exchange, Throwable exception) {
+        Exchange copy;
         if (exchange == null) {
-            exchange = consumer.getEndpoint().createExchange();
+            copy = consumer.getEndpoint().createExchange();
+        } else {
+            // use a copy to as must be processed independently unit of work
+            copy = ExchangeHelper.createCorrelatedCopy(exchange, false);
         }
 
         // set the caused exception
-        exchange.setException(exception);
-        exchange.setProperty(ExchangePropertyKey.EXCEPTION_CAUGHT, exception);
+        copy.setException(exception);
+        copy.setProperty(ExchangePropertyKey.EXCEPTION_CAUGHT, exception);
         // and the message
-        exchange.getIn().setBody(message);
+        copy.getIn().setBody(message);
         // mark as bridged
-        exchange.setProperty(ExchangePropertyKey.ERRORHANDLER_BRIDGE, true);
+        copy.setProperty(ExchangePropertyKey.ERRORHANDLER_BRIDGE, true);
         // and mark as redelivery exhausted as we cannot do redeliveries
-        exchange.getExchangeExtension().setRedeliveryExhausted(true);
+        copy.getExchangeExtension().setRedeliveryExhausted(true);
 
         // wrap in UoW
         UnitOfWork uow = null;
         try {
-            uow = consumer.createUoW(exchange);
-            bridge.process(exchange);
+            uow = consumer.createUoW(copy);
+            // process synchronously
+            bridge.process(copy);
         } catch (Exception e) {
-            fallback.handleException("Error handling exception " + exception.getMessage(), exchange, e);
+            fallback.handleException(
+                    "Error bridge handling existing exception " + exception.getMessage() + " due to: " + e.getMessage(), copy,
+                    e);
         } finally {
-            UnitOfWorkHelper.doneUow(uow, exchange);
+            UnitOfWorkHelper.doneUow(uow, copy);
         }
     }
 }