Monotonic Counters: A New Mechanism for Thread Synchronization

Only a handful of fundamental mechanisms for synchronizing the access of concurrent threads to shared memory are widely implemented and used. These include locks, condition variables, semaphores, barriers, and monitors. In this paper, we introduce a new synchronization mechanism—monotonic counters—and make a case for its addition to this group. Unlike most other synchronization mechanisms, monotonic counters were designed primarily for multiprocessing, rather than for systems programming. Counters have a very simple definition: a counter object has a nonnegative value, an Increment operation, and a Check operation. Increment atomically increases the counter, and Check suspends until the counter reaches a specified level. We demonstrate that many practical thread synchronization patterns can be expressed more elegantly using counters then with other synchronization mechanisms. Of particular importance, the monotonicity of counters can be used to guarantee deterministic synchronizat...

• Type: Conference
• Year: 2000
• Where: IPPS
• Authors: John Thornley, K. Mani Chandy
• Keywords: Counters, Distributed And Parallel Computing, IPPS 2000, Synchronization, Synchronization Mechanisms