Asynchronous Publisher

Concept

This example shows how to configure a datawriter for asynchronous publication. This means that instead of sending a sample before returning from write(), the data is enqueued and sent according to a flow controller.

There are three default flow controllers available.

• The first performs no throttling, and allows data to be send as soon as write() is called.
• The second, a fixed rate flow controller, allows data to be sent only once per second.
• The third allows manual control; that is, accumulated data is sent only on calls to trigger_flow(). All flow controllers allow messages to be coalesced into as few network packets as possible.

It is also possible to create custom flow controllers.

Example Description

This example uses the fixed rate flow controller. Such a flow controller might be useful when sending many small samples to minimize packet overhead. To illustrate the batching, we write 10 samples per second to DDS, which sends them together once per second.

In this example, the publisher application is configured to send data asynchronously. This means that when the data is sent, it is stored in the DataWriter's queue until the flow controller allows it to be sent. There are no changes on the DataReader side.

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