From: Jurgen Vinju To: Date: Wed, 29 Mar 2006 09:57:59 +0200 Subject: PEM: Dr. Uday Khedker, Monday April 3rd at 14:00 Dear colleagues, You are cordially invited to attend the following presentation by Dr. Uday Khedker from Bombai on Heap Reference Analysis. BEWARE that this PEM is not at the regular time or day, but on a Monday at 14:00. Date: Monday April 3rd 2006 Time: 14:00 Venue: M280 at CWI Heap Reference Analysis ------------------------- Despite significant progress in the theory and practice of program analysis, analysing properties of heap data has not reached the same level of maturity as the analysis of static and stack data. The spatial and temporal structure of stack and static data is well understood while that of heap data seems arbitrary and is unbounded. We devise bounded representations which summarize properties of the heap data. This summarization is based on the structure of the program which manipulates the heap. The resulting summary representations are certain kinds of graphs called access graphs. The boundedness of these representations and the monotonicity of the operations to manipulate them make it possible to compute them through data flow analysis. An important application which benefits from heap reference analysis is garbage collection, where currently liveness is conservatively approximated by reachability from program variables. As a consequence, current garbage collectors leave a lot of garbage uncollected, a fact which has been confirmed by several empirical studies. We propose the first ever end-to-end static analysis to distinguish live objects from reachable objects. We use this information to make dead objects unreachable by modifying the program. This application is interesting because it requires discovering data flow information representing complex semantics. In particular, we discover four properties of heap data: liveness, aliasing, availability, and anticipability. Together, they cover all combinations of directions of analysis (i.e. forward and backward) and confluence of information (i.e. union and intersection). Speaker: Dr. Uday Khedker Associate Professor Department of Computer Science & Engg. IIT Bombay, Powai, Mumbai 400 076, India. homepage: http://www.cse.iitb.ac.in/~uday Best regards, Jurgen Vinju -- http://www.cwi.nl/~pem