A minimal property for characterizing deadlock-free programs

A fundamental issue in the development of concurrent programs is the resource allocation problem. Roughly speaking, it consists of providing some mechanism to avoid race conditions in the access of shared resources by two or more concurrent processes. For such a task, maybe the most widely mechanism consists of using critical sections. Unfortunately, it is also widely-known that programs which use several critical sections may suffer from deadlocks. In this paper, we identify a program property, namely, being stopper-free, which can be used to know if programs are deadlock-free. Indeed, since we have proved that programs are deadlock-free if and only if they do not have any stopper, thus looking for a stopper is equivalent to identifying a situation where a program may suffer a deadlock.  2001 Elsevier Science B.V. All rights reserved.