Throughput Barrier Exploration for the Garbage-First Collector

The write barrier used by the Garbage-First (G1) collector is known to negatively impact application throughput. Detrimental effects of the barrier are attributed to its complexity and have been well-known within the OpenJDK development community, with potential impacts quantified in scientific research. This thesis designs two alternative throughputoriented barriers for G1 and develops necessary garbage collector adaptations. In addition, a prototype of run time dynamic barrier switch is implemented. Proposed throughputoriented barriers are evaluated using a diverse benchmark suite: it is shown that substantial throughput improvements are achieved at the expense of moderate increases in garbage collection pause times with new throughput-oriented barriers. Trade-offs provided by the new barriers are highly advantageous in certain application classes, although their benefits are not universal due to exhibited pause time impacts. Dynamic barrier switch enables additional flexibility in the context of balance between throughput and pause times.