Deadlock due to locking of DelayedProduce and group

From a local run of TransactionsBounceTest. Looks like we hold group lock while completing DelayedProduce, which in turn may acquire group lock.

Found one Java-level deadlock:
=============================
"kafka-request-handler-7":
waiting to lock monitor 0x00007fe08891fb08 (object 0x000000074a9fbc50, a kafka.coordinator.group.GroupMetadata),
which is held by "kafka-request-handler-4"
"kafka-request-handler-4":
waiting to lock monitor 0x00007fe0869e4408 (object 0x0000000749be7bb8, a kafka.server.DelayedProduce),
which is held by "kafka-request-handler-3"
"kafka-request-handler-3":
waiting to lock monitor 0x00007fe08891fb08 (object 0x000000074a9fbc50, a kafka.coordinator.group.GroupMetadata),
which is held by "kafka-request-handler-4"

Java stack information for the threads listed above:
===================================================
"kafka-request-handler-7":
at kafka.coordinator.group.GroupMetadataManager$$anonfun$handleTxnCompletion$1.apply(GroupMetadataManager.scala:752)
waiting to lock <0x000000074a9fbc50> (a kafka.coordinator.group.GroupMetadata)
at kafka.coordinator.group.GroupMetadataManager$$anonfun$handleTxnCompletion$1.apply(GroupMetadataManager.scala:750)
at scala.collection.mutable.HashSet.foreach(HashSet.scala:78)
at kafka.coordinator.group.GroupMetadataManager.handleTxnCompletion(GroupMetadataManager.scala:750)
at kafka.coordinator.group.GroupCoordinator.handleTxnCompletion(GroupCoordinator.scala:439)
at kafka.server.KafkaApis.kafka$server$KafkaApis$$maybeSendResponseCallback$1(KafkaApis.scala:1556)
at kafka.server.KafkaApis$$anonfun$handleWriteTxnMarkersRequest$1$$anonfun$apply$20.apply(KafkaApis.scala:1614)
at kafka.server.KafkaApis$$anonfun$handleWriteTxnMarkersRequest$1$$anonfun$apply$20.apply(KafkaApis.scala:1614)
at kafka.server.DelayedProduce.onComplete(DelayedProduce.scala:134)
at kafka.server.DelayedOperation.forceComplete(DelayedOperation.scala:66)
at kafka.server.DelayedProduce.tryComplete(DelayedProduce.scala:116)
at kafka.server.DelayedProduce.safeTryComplete(DelayedProduce.scala:76)
locked <0x000000074b21c968> (a kafka.server.DelayedProduce)
at kafka.server.DelayedOperationPurgatory$Watchers.tryCompleteWatched(DelayedOperation.scala:338)
at kafka.server.DelayedOperationPurgatory.checkAndComplete(DelayedOperation.scala:244)
at kafka.server.ReplicaManager.tryCompleteDelayedProduce(ReplicaManager.scala:284)
at kafka.cluster.Partition.tryCompleteDelayedRequests(Partition.scala:434)
at kafka.cluster.Partition.updateReplicaLogReadResult(Partition.scala:285)
at kafka.server.ReplicaManager$$anonfun$updateFollowerLogReadResults$2.apply(ReplicaManager.scala:1290)
at kafka.server.ReplicaManager$$anonfun$updateFollowerLogReadResults$2.apply(ReplicaManager.scala:1286)
at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
at kafka.server.ReplicaManager.updateFollowerLogReadResults(ReplicaManager.scala:1286)
at kafka.server.ReplicaManager.fetchMessages(ReplicaManager.scala:786)
at kafka.server.KafkaApis.handleFetchRequest(KafkaApis.scala:598)
at kafka.server.KafkaApis.handle(KafkaApis.scala:100)
at kafka.server.KafkaRequestHandler.run(KafkaRequestHandler.scala:65)
at java.lang.Thread.run(Thread.java:748)
"kafka-request-handler-4":
at kafka.server.DelayedProduce.safeTryComplete(DelayedProduce.scala:75)
waiting to lock <0x0000000749be7bb8> (a kafka.server.DelayedProduce)
at kafka.server.DelayedOperationPurgatory$Watchers.tryCompleteWatched(DelayedOperation.scala:338)
at kafka.server.DelayedOperationPurgatory.checkAndComplete(DelayedOperation.scala:244)
at kafka.server.ReplicaManager.tryCompleteDelayedProduce(ReplicaManager.scala:284)
at kafka.cluster.Partition.tryCompleteDelayedRequests(Partition.scala:434)
at kafka.cluster.Partition.appendRecordsToLeader(Partition.scala:516)
at kafka.server.ReplicaManager$$anonfun$appendToLocalLog$2.apply(ReplicaManager.scala:707)
at kafka.server.ReplicaManager$$anonfun$appendToLocalLog$2.apply(ReplicaManager.scala:691)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.immutable.Map$Map1.foreach(Map.scala:116)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
at scala.collection.AbstractTraversable.map(Traversable.scala:104)
at kafka.server.ReplicaManager.appendToLocalLog(ReplicaManager.scala:691)
at kafka.server.ReplicaManager.appendRecords(ReplicaManager.scala:441)
at kafka.coordinator.group.GroupMetadataManager.appendForGroup(GroupMetadataManager.scala:240)
at kafka.coordinator.group.GroupMetadataManager.storeGroup(GroupMetadataManager.scala:228)
at kafka.coordinator.group.GroupCoordinator.onCompleteJoin(GroupCoordinator.scala:731)
locked <0x000000074a9fbc50> (a kafka.coordinator.group.GroupMetadata)
at kafka.coordinator.group.DelayedJoin.onComplete(DelayedJoin.scala:44)
at kafka.server.DelayedOperation.forceComplete(DelayedOperation.scala:66)
at kafka.coordinator.group.DelayedJoin$$anonfun$tryComplete$1.apply$mcZ$sp(DelayedJoin.scala:42)
at kafka.coordinator.group.GroupCoordinator.tryCompleteJoin(GroupCoordinator.scala:708)
locked <0x000000074a9fbc50> (a kafka.coordinator.group.GroupMetadata)
at kafka.coordinator.group.DelayedJoin.tryComplete(DelayedJoin.scala:42)
at kafka.coordinator.group.DelayedJoin.safeTryComplete(DelayedJoin.scala:40)
at kafka.server.DelayedOperationPurgatory.tryCompleteElseWatch(DelayedOperation.scala:199)
at kafka.coordinator.group.GroupCoordinator.prepareRebalance(GroupCoordinator.scala:693)
at kafka.coordinator.group.GroupCoordinator.kafka$coordinator$group$GroupCoordinator$$maybePrepareRebalance(GroupCoordinator.scala:668)
locked <0x000000074a9fbc50> (a kafka.coordinator.group.GroupMetadata)
at kafka.coordinator.group.GroupCoordinator.removeMemberAndUpdateGroup(GroupCoordinator.scala:700)
at kafka.coordinator.group.GroupCoordinator.handleLeaveGroup(GroupCoordinator.scala:324)
locked <0x000000074a9fbc50> (a kafka.coordinator.group.GroupMetadata)
at kafka.server.KafkaApis.handleLeaveGroupRequest(KafkaApis.scala:1259)
at kafka.server.KafkaApis.handle(KafkaApis.scala:112)
at kafka.server.KafkaRequestHandler.run(KafkaRequestHandler.scala:65)
at java.lang.Thread.run(Thread.java:748)
"kafka-request-handler-3":
at kafka.coordinator.group.GroupMetadataManager$$anonfun$handleTxnCompletion$1.apply(GroupMetadataManager.scala:752)
waiting to lock <0x000000074a9fbc50> (a kafka.coordinator.group.GroupMetadata)
at kafka.coordinator.group.GroupMetadataManager$$anonfun$handleTxnCompletion$1.apply(GroupMetadataManager.scala:750)
at scala.collection.mutable.HashSet.foreach(HashSet.scala:78)
at kafka.coordinator.group.GroupMetadataManager.handleTxnCompletion(GroupMetadataManager.scala:750)
at kafka.coordinator.group.GroupCoordinator.handleTxnCompletion(GroupCoordinator.scala:439)
at kafka.server.KafkaApis.kafka$server$KafkaApis$$maybeSendResponseCallback$1(KafkaApis.scala:1556)
at kafka.server.KafkaApis$$anonfun$handleWriteTxnMarkersRequest$1$$anonfun$apply$20.apply(KafkaApis.scala:1614)
at kafka.server.KafkaApis$$anonfun$handleWriteTxnMarkersRequest$1$$anonfun$apply$20.apply(KafkaApis.scala:1614)
at kafka.server.DelayedProduce.onComplete(DelayedProduce.scala:134)
at kafka.server.DelayedOperation.forceComplete(DelayedOperation.scala:66)
at kafka.server.DelayedProduce.tryComplete(DelayedProduce.scala:116)
at kafka.server.DelayedProduce.safeTryComplete(DelayedProduce.scala:76)
locked <0x0000000749be7bb8> (a kafka.server.DelayedProduce)
at kafka.server.DelayedOperationPurgatory$Watchers.tryCompleteWatched(DelayedOperation.scala:338)
at kafka.server.DelayedOperationPurgatory.checkAndComplete(DelayedOperation.scala:244)
at kafka.server.ReplicaManager.tryCompleteDelayedProduce(ReplicaManager.scala:284)
at kafka.server.ReplicaManager$$anonfun$updateFollowerLogReadResults$2.apply(ReplicaManager.scala:1294)
at kafka.server.ReplicaManager$$anonfun$updateFollowerLogReadResults$2.apply(ReplicaManager.scala:1286)
at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
at kafka.server.ReplicaManager.updateFollowerLogReadResults(ReplicaManager.scala:1286)
at kafka.server.ReplicaManager.fetchMessages(ReplicaManager.scala:786)
at kafka.server.KafkaApis.handleFetchRequest(KafkaApis.scala:598)
at kafka.server.KafkaApis.handle(KafkaApis.scala:100)
at kafka.server.KafkaRequestHandler.run(KafkaRequestHandler.scala:65)
at java.lang.Thread.run(Thread.java:748)

Found 1 deadlock.