DEPRECATED: Topic locking
All locking of the topic state is handled automatically. However, when the state of the topic is not maintained by the topic (the topic is stateless), it is the responsibility of the publisher application to handle locking.
The publisher must consider the issue of locking the topic whilst its state is changed and delta messages published.
By default, all topics have locking enabled which allows the publisher to lock and unlock the topic as required. When a client subscribes to a topic the subscription method of the publisher, normally sends the current state of the topic to the client.
Threads that update the topic state and publish messages must also lock the topic for the duration of the update and publish. If this technique is not employed, a delta message might be sent to a client before the subscription method has the opportunity to send a topic load message. This can cause a failure at the client if topic aliasing is in use as aliasing relies upon the topic load message reaching the client first. Even if topic aliasing were not in use, the client application must be prepared for a delta arriving before the topic load.