Reading and updating agents

Agents are used to provide shared access to storage locations. They provide independent, asynchronous change of individual locations. Agents are bound to a single storage location for their lifetime and only allow mutation of that location (to a new state) to occur as a result of an action. Actions are functions (with, optionally, additional arguments) that are asynchronously applied to an agent's state and whose return value becomes the Agent's new state.

While updates to Agents are asynchronous, the state of an Agent is always immediately available for reading by any thread using get or apply without any messages.

Getting ready

Before we go through this recipe, we will need to download the akka-agent dependency in our project. For this, we will need to add the following dependency to the project's build.sbt:

libraryDependencies += "com.typesafe.akka" % "akka-agent_2.11" % "2.4.4" 

Now, open the terminal in Linux or command prompt in Windows and go to the project...