Progress: A Toolkit for Interactive Program Steering

Interactive program steering permits researchers to monitor and guide their applications during runtime. Interactive steering can help make end users more effective in addressing the scientific or engineering questions being solved with these programs, and it may be used to improve the performance of complex parallel and distributed codes. Progress is a toolkit for developing steerable applications. Users instrument their applications with library calls and then steer parallel applications with Progress’ runtime system. Progress provides steerable objects which encapsulate program abstractions for monitoring and steering during program execution. Once created, steering objects are known to and manipulated by Progress' two components: (1) a server executing in the same memory space as the target program and capable of inspecting and manipulating program state, and (2) a potentially remote client providing command and graphical interfaces. Developers instrument their applications with the Progress toolkit library to create and maintain these steering objects. The server maintains information about the steering objects and performs steering actions on the application. This toolkit provides sensors, probes, actuators, function hooks, complex actions, and synchronization points. Progress’ server is built on a Mach-compatible Cthreads library; it is a general toolkit for use with a variety of multithreaded, C programs executing on multiprocessors. Progress has been applied to several large-scale parallel application programs, including a molecular dynamics code and an N bodies simulation. It is currently being used with a complex global atmospheric modeling code.