Eliminating Concurrency Bugs in Multithreaded Software: A New Approach Based on Discrete-Event Control

Abstract

Abstract-Computer hardware is moving from uniprocessor to multicore architectures. One problem arising in this evolution is that only parallel software can exploit the full performance potential of multicore architectures, and parallel software is far harder to write than conventional serial software. One important class of failures arising in parallel software is circularwait deadlock in multithreaded programs. In our on-going Gadara project, we use a special class of Petri nets, called Gadara nets, to systematically model multithreaded programs with lock allocation and release operations. In this paper, we propose an efficient optimal control synthesis methodology for ordinary Gadara nets that exploits the structural properties of Gadara nets via siphon analysis. Optimality in this context refers to the elimination of deadlocks in the program with minimally restrictive control logic. We formally establish a set of important properties of the proposed control synthesis methodology, and show that our algorithms never synthesize redundant control logic. We conduct experiments to evaluate the efficiency and scalability of the proposed methodology, and discuss the application of our results to real-world concurrent software.

Modern software cybernetics: New trends

“…Several industrial case studies highlighted the advantages of the proposed approach. Liao et al (2013) used a special class of Petri nets, called Gadara nets, to systematically model multithreaded programs with lock allocation and release operations. They proposed an efficient optimal control synthesis methodology for ordinary Gadara nets that exploited the structural properties of Gadara nets via siphon analysis.…”

Optimal Liveness-Enforcing Control for a Class of Petri Nets Arising in Multithreaded Software

“…The key of the Monitor Place Synthesis Algorithm is to find an appropriate linear inequality constraint in the form of (19) for each element C u ∈ C (2) u , so that we can employ SBPI to synthesize a monitor place to prevent C u , and finally obtain an admissible controlled Gadara net. In general, for any given C u ∈ C (2) u , we can find an associated linear inequality constraint in two stages.…”

“…In Stage 1, we specify a linear inequality constraint in the form of (19) for C u , according to the discussion following Theorem 2. From the above discussion of UCCOR, we know that C u contains only "1" or "χ" components.…”

“…Further customized algorithms can be developed for particular concurrent software applications, which are beyond the scope of this paper and will be presented in another paper [19], along with experimental results on their performance. The main contributions of this paper can be summarized as follows: (i) We present a new iterative control synthesis scheme (called ICOG) for Gadara nets; this scheme is based on structural analysis and converges in finite iterations.…”

Eliminating Concurrency Bugs in Multithreaded Software: An Approach Based on Control of Petri Nets

“…The general framework of this methodology, called ICOG for Iterative Control Of Gadara nets, is presented in [31], while its customization to the case of programs modeled by Gadara nets is presented in [32] and referred to as ICOG-O therein, since the nets involved remain ordinary throughout the iterations. This approach does not guarantee at the outset that the number of control places will be minimized.…”