## Abstract

High-quality *asynchronous programs* are needed urgently to exploit multi-core hardware and cloud platforms. However, in real-time systems, formal models such as *timed automata (TAs)* are limited to *concurrent programs* where the number of processes is constant and no process is triggered on-the-fly. To better support the verification of *asynchronous programs*, we propose a new model called *asynchronous multi-process timed automata (APTAs)* based on TAs. Processes are abstracted as *process timed automata (PTAs)*, which are almost the same as TAs except some states are for triggering new processes. A multiset is used to buffer triggered instances. The model is sufficiently expressive to describe *real-time asynchronous programs* with dynamic process creation. We show that the coverability problem, which is used for checking safety property of programs, is decidable by encoding it into *read-arc timed Petri nets (RTPNs)*. We then propose an algorithm for the coverability problem and provide a proof of the termination and correctness.

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## Acknowledgements

This study is supported by the National Natural Science Foundation of China (Nos. 61672340, 61472238, and 61472240).

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Li, G., Liu, L. & Fukuda, A. Asynchronous multi-process timed automata.
*Software Qual J* **26, **961–989 (2018). https://doi.org/10.1007/s11219-017-9380-8

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### Keywords

- Asynchronous multi-process timed automata
- Coverability
- Read-arc timed Petri nets
- Timed automata