MetaPubSub is an implementation of the publish/subscribe pattern - when the publisher and subscriber know nothing of each other but can exchange messages. It's fast, lightweight and beside basic functionality has some cool features:

• interprocess communication - messages can be sent between different processes and computers
• the independent order of the Subscribe and Publish methods
• awaitable methods, for example, you can await Publish and wait until all subscribers have finished processing the message
• at least once delivery check - you can opt in to have an exception if no one subscribed to your message
• message filtering - you can define a predicate to subscribe only those messages you want to process
• timeout to wait for a subscriber - your message can be queued and wait until someone subscribed and processed it
• scheduling a message - your message can be queued and published after a time delay
• asynchronous waiting for a specified message by a single method call, without need to Subscribe/Unsubscribe to this message
• request-response pattern - send a message and wait for the response as a single awaitable method, without need to Subscribe/Unsubscribe to the response message
• cancellation token support - you can cancel scheduling or waiting for the message
• exceptions handling - all exceptions raised when a message processing by subscribers can be caught by the publisher as an AggregateException

To install the Meta.Lib run the following command:

PM> Install-Package Meta.Lib 

Note: this version has breaking changes.

• IPubSubMessage.Timeout renamed to WaitForSubscriberTimeout
• Added IPubSubMessage.ResponseTimeout - Time interval during which the response message must be received otherwise the TimeoutException will be thrown. Used in IMetaPubSub.Process() and IMetaPubSub.ProcessOnServer()
• Removed parameter millisecondsTimeout from IMetaPubSub.Process() and IMetaPubSub.ProcessOnServer(). Use IPubSubMessage.ResponseTimeout instead
• Fixed bug: timeout in IMetaPubSub.Process() and IMetaPubSub.ProcessOnServer() always use it's default value of 5 sec.

• Added TryConnectToServer & TrySubscribeOnServer
• Added a match predicate to SubscribeOnServer method
• Added Connected/Disconnected built-in messages
• Added a delegate method to create a pipe with non-default parameters

• Interprocess communication implemented