AbstractDeveloping concurrent applications is not a trivial task. As programs grow larger and become more complex, advanced concurrency control mechanisms are needed to ensure that application consistency is not compromised. Managing mutual exclusion on a per‐object basis is not sufficient to guarantee isolation of sets of semantically‐related actions. In this paper, we consider ‘atomic blocks’, a simple and lightweight concurrency control paradigm that enables arbitrary blocks of code to access multiple shared objects in isolation. We evaluate various strategies for implementing atomic blocks in Java, in such a way that concurrency control is transparent to the programmer, isolation is preserved, and concurrency is maximized. We discuss these concurrency control strategies and evaluate them in terms of complexity and performance. Copyright © 2002 John Wiley & Sons, Ltd.