Real-world application improvement with user controlled object sharing

Abstract

An analysis of sharing string objects with the Java Virtual Machine was conducted; they are the most used objects in Java programs and they are immutable - thus they are read-only and easily identified. While the results are promising, it is clear that sharing more objects would result in better performance. Automatic object selection for sharing is non-trivial, because in the current state only read-only objects can be shared. This attribute can not be easily determined during runtime by an algorithm; the developer on the other hand can. This thesis presents the development of an Application Programmer Interface (API) that allows programmers to use the Java Virtual Machine (JVM) internal sharing functionality. Furthermore, we present the usage of the sharing API. Open-source software was used as real-world test cases. Afterwards the evaluation shows that the ratio between memory savings and start-up time overhead is reasonable.