Task termination in Ada 95

Abstract

Ada 83 removed from the programmer the burden of coding potentially complex termination conditions between clients and servers by introducing an ‘or terminate’ option to the select statement. With the use of indirect communication (emphasised by the provision of protected objects in Ada 95), it is no longer straightforward to obtain program termination. This paper illustrates the problem and shows how the asynchronous select statement and a general-purpose library package can be used to simplify the termination protocols. The advantages and disadvantages of the approach are discussed. The paper then considers the extent to which termination could be supported in Ada. It explores the idea of having a termination option with an entry call.