print page


Cloned Transactions

Start 15. January 2010
End 31. December 2014
Financing Hamburg University of Technology

Project Description

These are the results of a Phd. thesis on a new concept for transactional memory, which consideres parallel execution of clones of a single transaction to reduce progress loss through conflicts with other transactions.

Traditionally, a transaction is executed by a single thread or process. In case of a conflict with another transaction, a transaction has to rollback to its begin and restart its execution. This causes loss of progress, i.e. execution time.

This issue can be depicted by trains which have to transport bulk good over a given railway network from one location to another. The train conductors do not know about the situation in the railway network and thus, just try to head straight towards its destination. This causes accidents between trains meeting each other on the same route. In an accident at least one of the trains looses its cargo and has to return to its start location to pickup the goods again. In this imagination, trains with cargo and an assigned start and destination represent transactions and accidents represent conflicts with other transactions.

The concept proposed in this thesis is as follows: Because the goods are not unique, it is possible to sent another train with the same goods to the same location (a clone of the transaction) but using a different route through the railway system. In case one of the trains is involved in an accident, its clone might still safely reach its destination and thereby finish the actual task.

Subject of this phd. thesis is the analysis and evaluation of different approaches to apply this execution concept to transactions in transactional memory. The link provide below refers to a package which contains all results of the thesis.