Semantics-Preserving and Incremental Runtime Patching of Real-Time Programs

The authors propose semantics-preserving and incremental run-time patching of real-time programs as a robust means for reconfiguring hard real-time systems at run-time. They consider programs that describe non-functional aspects of processes such as their timing properties and communication behavior, and give examples written in the Hierarchical Timing Language (HTL). Run-time patching is the process of replacing portions of such programs at run-time by new code. It is semantics-preserving if the switch to the resulting code and the code itself could have been compiled beforehand, had the patch been known. It is incremental if analyzing and generating the code only involves an effort proportional to the size of the patch, not the patched program.