Introduction

ABS Async API is an implementation of ABS models asynchronous message passing using the features available in Java 8. The design and implementation is driven by certain requirements and principles from the scope of ABS models and platform.

ABS Async API introduces an independent Java library that can be freely used in any Java 8 compatible code base. The API implementation provides certain interfaces that allows Java objects to interact to one another through a message passing mechanism and process messages in an asynchronous and event-driven approach. The implementation separates invocation of messages from execution of messages. An invocation of a message to an object assures the delivery of the message to the receiver while execution of a message is the specifics of the message is processed. Such separation increases the extensibility and pluggability of the implementation in each layer. Morever, it evidently influences the performance of message processing and utilization of resources such as underlying Java threads.

ABS Async API is designed in such way that is it ready to be used for ABS model code generations. An ABS model can transformed into an implementation language such as Java. As an ABS model may take advantage of asynchronous message passing, the generated code is expected to expose the same semantics. The ABS Async API allows code generators to generate code lines using the API library to implement the asynchronous message passing at the level of Java 8.

ABS Async API realizes a one-to-one mapping from ABS asynchronous message passing to a Java 8 implementation. Such mapping provides a base ground to be able to formally reason about and verify the code generated from ABS models on top of such API implementation.