Graduate Alumnus Maged Michael Selected as a Co-Recipient of the 2022 Dijkstra Prize
April 20, 2022
Maged Michael, who received his PhD from URCS in 1997, has been selected a co-recipient of the 2022 SIGACT/SIGOPS Edsger W. Dijkstra Prize in Distributed Computing—the highest honor awarded in the theory of parallel and distributed computing. Long a member of technical staff at IBM Research, Maged moved to Facebook (now Meta) in 2016. This year's prize recognizes two concurrent papers:
- “Safe Memory Reclamation for Dynamic Lock-Free Objects Using Atomic Reads and Writes,” by Maged M. Michael. Proceedings of the 22nd ACM Symposium on Principles of Distributed Computing (PODC), Monterey, CA, USA, July 2002, pages 21–30.
- “The Repeat Offender Problem: A Mechanism for Supporting Dynamic-Sized, Lock-Free Data Structures,” by Maurice Herlihy, Victor Luchangco, and Mark Moir. Proceedings of the 16th International Symposium on Distributed Computing (DISC), Toulouse, France, October 2002, pages 339–353.
The award citation reads:
Hazard Pointers, also known as the “Pass the Buck” solution to the Repeat Offenders Problem, were the first general-purpose solution to the memory management problem in nonblocking concurrent data structures. They remain the dominant solution today. By maintaining a global set of references to objects (nodes) to which active threads hold private references, they enable nonblocking code to determine when a node can safely be reclaimed. By organizing the set as a collection of per-thread structures, each of which is accessed primarily by its owner, they avoid most nonlocal references, keeping overhead low enough for all but the most demanding applications. More, perhaps, than any other single innovation, hazard pointers have enabled nonblocking concurrent data structures to become a central technology of modern parallel systems.