Contention on network registry during concurrent additions and removals

[simon622]

"mqtt-sn-udp-transport-ingress-1771667101-1" #25 daemon prio=2 os_prio=31 cpu=8203.20ms elapsed=9.00s tid=0x000000013b811000 nid=0x5607 runnable [0x000000016e252000]
java.lang.Thread.State: RUNNABLE
at java.util.HashMap$HashIterator.nextNode([email protected]/HashMap.java:1601)
at java.util.HashMap$KeyIterator.next([email protected]/HashMap.java:1620)
at org.slj.mqtt.sn.net.NetworkAddressRegistry.removeExistingClientId(NetworkAddressRegistry.java:137)
- locked <0x00000007f8499dd8> (a java.util.Collections$SynchronizedMap)
at org.slj.mqtt.sn.impl.AbstractMqttsnMessageHandler.authorizeContext(AbstractMqttsnMessageHandler.java:70)
at org.slj.mqtt.sn.impl.AbstractMqttsnTransport.receiveFromTransportInternal(AbstractMqttsnTransport.java:80)
at org.slj.mqtt.sn.impl.AbstractTransport.lambda$receiveFromTransport$1(AbstractTransport.java:120)
at org.slj.mqtt.sn.impl.AbstractTransport$$Lambda$190/0x0000000800da5d08.run(Unknown Source)
at java.util.concurrent.Executors$RunnableAdapter.call([email protected]/Executors.java:539)
at java.util.concurrent.FutureTask.run([email protected]/FutureTask.java:264)
at java.util.concurrent.ThreadPoolExecutor.runWorker([email protected]/ThreadPoolExecutor.java:1136)
at java.util.concurrent.ThreadPoolExecutor$Worker.run([email protected]/ThreadPoolExecutor.java:635)
at java.lang.Thread.run([email protected]/Thread.java:833)

[simon622]

Changed data model to allow for higher concurrency