A Note on the Implementation of Replication-Based Garbage Collection for Multithreaded Applications and Multiprocessor Environments

Replication-based incremental garbage collection [5, 4] is one of the more appealing concurrent garbage collection algorithms known today. It allows continuous operation of the application (the mutator) with very short pauses for garbage collection. There is a growing need for such garbage collectors suitable for a multithreaded environments such as the Java Virtual Machine. Furthermore, it is desirable to construct collectors that also work on multiprocessor computers. We begin by pointing out an important, yet subtle point which arises when implementing the replication based garbage collector for a multithreaded environment. We first show that a simple and natural implementation of the algorithm may lead to an incorrect behavior of multithreaded applications. We then show that another simple and natural implementation eliminates the problem completely. Thus, the contribution of this part is in stressing this warning to future implementors. Next, we address the effects of the memory c..