[Colloq] Talk, Today, 5pm - Ana-Maria Visan

[Rachel Kalweit]

Title: URDB: Universal Reversible Debugger

Speaker: Ana-Maria Visan

Place & Time: 166WVH - February 4, 5pm

Abstract:

URDB is a universal reversible debugger that adds reversibility to almost any debugger through a python-based wrapper. URDB is still experimental. URDB supports multi-threaded and multi-process applications, as well as distributed computations. It currently has four personality modules, which support: gdb; MATLAB; python (pdb); and perl (perl -d). URDB gains its reversibility through the use of DMTCP (Distributed MultiThreaded CheckPointing), a fast checkpoint-restart package.

URDB also supports reverse expression watchpoints, a form of temporal search within a process lifetime. For example, the current value of a user specified expression indicates a bug. The user asks URDB/gdb to go back in time to a statement where the expression is about to take on its current value. This uses binary search: if n statements have been executed, URDB finds the point in time using only log(n) evaluations of the expression.

The experimental software is available at: http://urdb.sourceforge.net/.