No abstract

Concurrent interaction of multi-processor systems result in errors which are difficult to find. Traditional simulationbased verification techniques remove the concurrency information by arbitrary schedulings. We present a novel simulation-based technique for SystemC that preserves and exploits concurrency information. Our approach is unique in that we can detect potential errors in an observed execution, even if the error does not actually occur in that execution. We identify synchronization constructs in SystemC and develop predictive techniques for temporal assertion verification and deadlock detection. Our automated potential deadlock detection algorithm works on SystemC programs with semaphores, locks, wait and notify synchronizations and has less overhead compared with assertion verification. We patched SystemC kernel to implement our solution and obtained favorable results on industrial designs.

Abstract. Given a set of n different deterministic finite state machines (DFSMs), we examine the problem of tolerating k faults among them. The traditional approach to this problem involves replication, requiring n.k backup DFSMs. For example, given two state machines, say A and B, to tolerate two faults, this approach maintains two copies each of A and B, thus resulting in a total of six DFSMs in the system. In this paper, we question the optimality of such an approach and present another approach based on the 'fusion' of state machines allowing for more efficient backups. We introduce the theory of fusion machines and provide an algorithm which can generate fusion machines corresponding to a given set of machines. Further, we have implemented this algorithm and tested it for various examples. It is important to note that our approach requires only k backup DFSMs, as opposed to the n.k backup DFSMs required by the replication approach.

Given a set of n different deterministic finite state machines (DFSMs)

Abstract. The earlier work on predicate detection has assumed that the given computation is finite. Detecting violation of a liveness predicate requires that the predicate be evaluated on an infinite computation. In this work, we develop the theory and associated algorithms for predicate detection in infinite runs. In practice, an infinite run can be determined in finite time only if it consists of a recurrent behavior with some finite prefix. Therefore, our study is restricted to such runs. We introduce the concept of d-diagram, which is a finite representation of infinite directed graphs. Given a d-diagram that represents an infinite distributed computation, we solve the problem of determining if a global predicate ever became true in the computation. The crucial aspect of this problem is the stopping rule that tells us when to conclude that the predicate can never become true in future. We also provide an algorithm to provide vector timestamps to events in the computation for determining the dependency relationship between any two events in the infinite run.