Concurrency bugs threaten the safety of shared-memory multithreaded programs. The automated fixing techniques add new synchronization constructs; existing techniques may add too many synchronization constructs, sacrifice too much concurrency, or introduce deadlocks. The underlying problem is that existing techniques cannot simultaneously fix different bugs, especially different types of bugs, w...

The actor model is an attractive foundation for developing concurrent applications because actors are isolated concurrent entities that communicate through asynchronous messages and do not share state. Thus, they avoid common concurrency bugs such as data races. However, they are not immune to concurrency bugs in general. This paper studies concurrency bugs in actor-based programs reported in l...

* This work has been supported by NSF grant MIP-9630096 Abstract In this paper we consider the problem of deadlock-free wormhole unicast routing in networks with irregular topologies. To prevent deadlocks, for each router some input/output pairs (turns) have to be prohibited. We analyze the problem of minimizing the number of prohibited turns for providing deadlock-free routing. A new algorithm...

In this paper we present the deadlock avoidance approach used in the design of the scheduling kernel of an Automatic Train Supervision (ATS) system. The ATS that we have designed prevents the occurrence of deadlocks by performing a set of runtime checks just before allowing a train to move further. For each train, the set of checks to be performed at each step of progress is retrieved from stat...

This article introduces a self-stabilizing deadlock-detection algorithm for the OR model. The algorithm is complete, because it detects all deadlocks, and it is correct, because it does not detect false deadlocks. Because of the self-stabilization property, the algorithm supports dynamic changes in the wait-for graph on which it works, and transient faults; also, it can be started in an arbitra...

In nite wait anomalies associated with a barrier rendezvous model (e.g., Ada) can be divided into two classes: stalls and deadlocks. Although precise static deadlock detection is NP-hard, we present two polynomial time algorithms which operate on a statically derivable program representation, the sync graph, to certify a useful class of programs free of deadlocks. We identify three conditions l...

We give two different notions of deadlock for systems based on active objects and futures. One is based on blocked objects and conforms with the classical definition of deadlock by Coffman, Jr. et al. The other one is an extended notion of deadlock based on blocked processes which is more general than the classical one. We introduce a technique to prove deadlock freedom of systems of active obj...