Systems of asynchronous sequential processes: the balance property and analysis of deadlock occurences

In this paper systems, composed by a set of communicating sequential processes, are analyzed. For a subclass of systems, necessary and sufficient conditions are determined in order to avoid deadlock conditions. The subclass of systems analyzed is constitute by sistems whose processes have a unique control sequence and where the process interaction is assured by message-buffers ("mailboxes") with only one sender and only one receiver. Deadlock conditions only caused by the interprocess communication mechanism are considered.