SimpleMessageListenerContainerTests#testAddQueuesAndStartInCycle fails with ConcurrentModificationException #3166
Description
In what version(s) of Spring AMQP are you seeing this issue?
main
Describe the bug
org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainerTests#testAddQueuesAndStartInCycle can fail with a ConcurrentModificationException on shutdown. It doesn't happen every time so either the test needs to be more robust or it exposes an actual issue in SimpleMessageListenerContainer:
2025-08-22 08:22:24,015 INFO org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer [main] : Waiting for workers to finish.
2025-08-22 08:22:24,016 INFO org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer [main] : Workers not finished.
2025-08-22 08:22:24,016 ERROR org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer [not.a.Spring.bean-3] : Stopping container from aborted consumer
org.springframework.amqp.UncategorizedAmqpException: java.util.ConcurrentModificationException
at org.springframework.amqp.rabbit.support.RabbitExceptionTranslator.convertRabbitAccessException(RabbitExceptionTranslator.java:81)
at org.springframework.amqp.rabbit.connection.RabbitAccessor.convertRabbitAccessException(RabbitAccessor.java:117)
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.shutdown(AbstractMessageListenerContainer.java:1345)
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.shutdown(AbstractMessageListenerContainer.java:1313)
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doStop(AbstractMessageListenerContainer.java:1468)
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.stop(AbstractMessageListenerContainer.java:1454)
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainerTests.testAddQueuesAndStartInCycle(SimpleMessageListenerContainerTests.java:417)
at java.base/java.lang.reflect.Method.invoke(Method.java:565)
at java.base/java.util.Optional.ifPresent(Optional.java:178)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:186)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:215)
at java.base/java.util.stream.IntPipeline$1$1.accept(IntPipeline.java:180)
at java.base/java.util.stream.Streams$RangeIntSpliterator.forEachRemaining(Streams.java:104)
at java.base/java.util.Spliterator$OfInt.forEachRemaining(Spliterator.java:712)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:570)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:560)
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:153)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:176)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:265)
at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:636)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)
Caused by: java.util.ConcurrentModificationException
at java.base/java.util.ArrayList.forEach(ArrayList.java:1606)
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.lambda$shutdownAndWaitOrCallback$0(SimpleMessageListenerContainer.java:709)
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.shutdownAndWaitOrCallback(SimpleMessageListenerContainer.java:736)
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.shutdown(AbstractMessageListenerContainer.java:1342)
... 19 more
To Reproduce
Replace @Test by @RepeatedTest(100) and it should eventually fail.