[
https://issues.apache.org/jira/browse/ROCKETMQ-107?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15881816#comment-15881816
]
ASF GitHub Bot commented on ROCKETMQ-107:
-----------------------------------------
Github user Ah39 commented on the issue:
https://github.com/apache/incubator-rocketmq/pull/68
**# apache/curator TreeCache Start**
public TreeCache start() throws Exception
{
**Preconditions.checkState(treeState.compareAndSet(TreeState.LATENT,
TreeState.STARTED)**, "already started");
if ( createParentNodes )
{
client.createContainers(root.path);
}
client.getConnectionStateListenable().addListener(connectionStateListener);
if ( client.getZookeeperClient().isConnected() )
{
root.wasCreated();
}
return this;
}
> Access ServiceState is not thread safe when start() or shutdown()
> -----------------------------------------------------------------
>
> Key: ROCKETMQ-107
> URL: https://issues.apache.org/jira/browse/ROCKETMQ-107
> Project: Apache RocketMQ
> Issue Type: Bug
> Components: rocketmq-client
> Reporter: Jaskey Lam
> Assignee: Jaskey Lam
> Priority: Minor
>
> When start() or shutdown(), service's state is not thread safe which may
> break happen-before.
> For example:
> switch (this.serviceState) {
> case CREATE_JUST:
> log.info("the consumer [{}] start beginning. messageModel={},
> isUnitMode={}", this.defaultMQPushConsumer.getConsumerGroup(),
> this.defaultMQPushConsumer.getMessageModel(),
> this.defaultMQPushConsumer.isUnitMode());
> this.serviceState = ServiceState.START_FAILED;
> ..// do some start job here
> this.serviceState = ServiceState.RUNNING;
> break;
> case RUNNING:
> case START_FAILED:
> case SHUTDOWN_ALREADY:
> throw new MQClientException("The PushConsumer service state
> not OK, maybe started once, "//
> + this.serviceState//
> + FAQUrl.suggestTodo(FAQUrl.CLIENT_SERVICE_NOT_OK),
> null);
> default:
> break;
> }
> 1. If the user is start twice in two thread, the resources may initize twice.
> 2. if the user start in threadA and shutdown very quicky in another thread B,
> shutdown may not reclaim the resources.
> Though the sceniro is very uncommon, but it is indeed a bug here. Fix is
> actually quite trivial.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
