A mechanism for encoding and reporting instrumented data is disclosed that requires less storage space and incurs less processor overhead than other methods of the prior art. In accordance with the illustrative embodiment, a bit vector in shared memory corresponds to nodes of a program's control-flow graph that have been instrumented, and the contents of the vector indicate which of these nodes have executed; in addition, character strings in shared memory indicate what file, class, and method each node belongs to. A process that executes concurrently with those of the program under test transmits instrumented data from the shared memory to a database. The illustrative embodiment enables efficient, rapid reporting and storage of instrumented data, and is therefore especially well-suited for run-time analysis of real-time concurrent systems.