Open nesting in software transactional memory

ABSTRACT

Transactional memory (TM) promises to simplify concurrent programming while providing scalability competitive to fine-grained locking. Language-based constructs allow programmers to denote atomic regions declaratively and to rely on the underlying system to provide transactional guarantees along with concurrency. In contrast with fine-grained locking, TM allows programmers to write simpler programs that are composable and deadlock-free.

TM implementations operate by tracking loads and stores to memory and by detecting concurrent conflicting accesses by different transactions. By automating this process, they greatly reduce the programmer's burden, but they also are forced to be conservative. Incertain cases, conflicting memory accesses may not actually violate the higher-level semantics of a program, and a programmer may wish to allow seemingly conflicting transactions to execute concurrently.

Open nested transactions enable expert programmers to differentiate between physical conflicts, at the level of memory, and logical conflicts that actually violate application semantics. A TMsystem with open nesting can permit physical conflicts that are not logical conflicts, and thus increase concurrency among application threads.

Here we present an implementation of open nested transactions in a Java-based software transactional memory (STM)system. We describe new language constructs to support open nesting in Java, and we discuss new abstract locking mechanisms that a programmer can use to prevent logical conflicts. We demonstrate how these constructs can be mapped efficiently to existing STM data structures. Finally, we evaluate our system on a set of Java applications and data structures, demonstrating how open nesting can enhance application scalability.

REFERENCES

• 1: Ali-Reza Adl-Tabatabai , Brian T. Lewis , Vijay Menon , Brian R. Murphy , Bratin Saha , Tatiana Shpeisman, Compiler and runtime support for efficient software transactional memory, Proceedings of the 2006 ACM SIGPLAN conference on Programming language design and implementation, June 11-14, 2006, Ottawa, Ontario, Canada
• 2: Brian D. Carlstrom , Austen McDonald , Hassan Chafi , JaeWoong Chung , Chi Cao Minh , Christos Kozyrakis , Kunle Olukotun, The Atomos transactional programming language, Proceedings of the 2006 ACM SIGPLAN conference on Programming language design and implementation, June 11-14, 2006, Ottawa, Ontario, Canada
• 3: Hector Garcia-Molina, Using semantic knowledge for transaction processing in a distributed database, ACM Transactions on Database Systems (TODS), v.8 n.2, p.186-213, June 1983 [doi>10.1145/319983.319985]
• 4: Jim Gray , Andreas Reuter, Transaction Processing: Concepts and Techniques, Morgan Kaufmann Publishers Inc., San Francisco, CA, 1992
• 5: Tim Harris , Keir Fraser, Language support for lightweight transactions, Proceedings of the 18th annual ACM SIGPLAN conference on Object-oriented programing, systems, languages, and applications, October 26-30, 2003, Anaheim, California, USA
• 6: Tim Harris , Simon Marlow , Simon Peyton-Jones , Maurice Herlihy, Composable memory transactions, Proceedings of the tenth ACM SIGPLAN symposium on Principles and practice of parallel programming, June 15-17, 2005, Chicago, IL, USA [doi>10.1145/1065944.1065952]
• 7: Maurice Herlihy , Victor Luchangco , Mark Moir , William N. Scherer, III, Software transactional memory for dynamic-sized data structures, Proceedings of the twenty-second annual symposium on Principles of distributed computing, p.92-101, July 13-16, 2003, Boston, Massachusetts [doi>10.1145/872035.872048]
• 8: Maurice Herlihy , J. Eliot B. Moss, Transactional memory: architectural support for lock-free data structures, Proceedings of the 20th annual international symposium on Computer architecture, p.289-300, May 16-19, 1993, San Diego, California, United States
• 9: Virendra J. Marathe , William N. Scherer , Michael L. Scott, Design tradeoffs in modern software transactional memory systems, Proceedings of the 7th workshop on Workshop on languages, compilers, and run-time support for scalable systems, p.1-7, October 22-23, 2004, Houston, Texas [doi>10.1145/1066650.1066660]
• 10: Austen McDonald , JaeWoong Chung , Brian D. Carlstrom , Chi Cao Minh , Hassan Chafi , Christos Kozyrakis , Kunle Olukotun, Architectural Semantics for Practical Transactional Memory, Proceedings of the 33rd annual international symposium on Computer Architecture, p.53-65, June 17-21, 2006
• 11: Michelle J. Moravan , Jayaram Bobba , Kevin E. Moore , Luke Yen , Mark D. Hill , Ben Liblit , Michael M. Swift , David A. Wood, Supporting nested transactional memory in logTM, Proceedings of the 12th international conference on Architectural support for programming languages and operating systems, October 21-25, 2006, San Jose, California, USA
• 12: J. Eliot B. Moss. Nested transactions: an approach to reliable distributed computing. PhD thesis, Massachusetts Institute of Technology, Cambridge, MA, USA, 1981.
• 13: J. Eliot B. Moss. Open nested transactions: Semantics and support. In WMPI 2005, 2005. Poster presentation.
• 14: J. Eliot B. Moss and Antony L. Hosking. Nested transactional memory: model and preliminary architecture sketches. In OOPSLA Workshop on Synchronization and Concurrency in Object-Oriented Languages (SCOOL), 2005.
• 15: J. Eliot B. Moss , Antony L. Hosking, Nested transactional memory: model and architecture sketches, Science of Computer Programming, v.63 n.2, p.186-201, 1 December 2006 [doi>10.1016/j.scico.2006.05.010]
• 16: Nathaniel Nystrom, Michael R. Clarkson, and Andrew C. Myers. Polyglot: an extensible compiler framework for Java. In CC: International Conference on Compiler Construction, Lecture Notes in Computer Science 2622, pages 138--152, April 2003.
• 17: Ravi Rajwar , Maurice Herlihy , Konrad Lai, Virtualizing Transactional Memory, Proceedings of the 32nd annual international symposium on Computer Architecture, p.494-505, June 04-08, 2005
• 18: Michael F. Ringenburg , Dan Grossman, AtomCaml: first-class atomicity via rollback, Proceedings of the tenth ACM SIGPLAN international conference on Functional programming, September 26-28, 2005, Tallinn, Estonia
• 19: Bratin Saha , Ali-Reza Adl-Tabatabai , Richard L. Hudson , Chi Cao Minh , Benjamin Hertzberg, McRT-STM: a high performance software transactional memory system for a multi-core runtime, Proceedings of the eleventh ACM SIGPLAN symposium on Principles and practice of parallel programming, March 29-31, 2006, New York, New York, USA [doi>10.1145/1122971.1123001]
• 20: Nir Shavit , Dan Touitou, Software transactional memory, Proceedings of the fourteenth annual ACM symposium on Principles of distributed computing, p.204-213, August 20-23, 1995, Ottowa, Ontario, Canada [doi>10.1145/224964.224987]
• 21: Gerhard Weikum, A theoretical foundation of multi-level concurrency control, Proceedings of the fifth ACM SIGACT-SIGMOD symposium on Principles of database systems, p.31-43, March 24-26, 1986, Cambridge, Massachusetts, United States [doi>10.1145/6012.15401]
• 22: Gerhard Weikum , Christof Hasse , Peter Broessler , Peter Muth, Multi-level recovery, Proceedings of the ninth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems, p.109-123, April 02-04, 1990, Nashville, Tennessee, United States [doi>10.1145/298514.298548]
• 23: Adam Welc, Suresh Jagannathan, and Antony L. Hosking. Transactional monitors for concurrent objects. In ECOOP 2004: European Conference on Object-Oriented Programming, volume 3086 of Lecture Notes in Computer Science, pages 519--542. Springer-Verlag, 2004.

INDEX TERMS

Primary Classification:
  D. Software
  D.3 PROGRAMMING LANGUAGES
      D.3.3 Language Constructs and Features
          Subjects: Concurrent programming structures

General Terms:
Design, Languages, Performance

Keywords:
abstract locks, nested transactions, open nesting, transactional memory