A language-based approach to deterministic execution debugging of concurrent Ada programs is presented. The approach is to define synchronization (SYN)-sequences of a concurrent Ada program in terms of Ada language constructs and to replay such SYN-sequences without the need for system-dependent debugging tools. It is shown how to define a SYN-sequence of a concurrent Ada program in order to provide sufficient information for deterministic execution. It is also shown how to transform a concurrent Ada program P so that the SYN-sequences of previous executions of P can be replayed. This transformation adds an Ada task to P that controls program execution by synchronizing with the original tasks in P. A brief description is given of the implementation of tools supporting deterministic execution debugging of concurrent Ada programs.>

The authors show how to accomplish deterministic execution debugging of a concurrent Ada program according to a given synchronization (SYN) sequence. They first define the format of a SYN sequence of a concurrent Ada program in order to provide sufficient information for deterministic execution. They show how to transform a concurrent Ada program P into a slightly different Ada program P' so that any execution of P' with (X,S) as input, where S is the SYN sequence of a previous execution of P with input X, definitely repeats S. Tools for transforming concurrent Ada programs for deterministic execution debugging are described.>