The article explains how ZGC achieves sub‑millisecond pause times by embedding GC state in pointer bits (colored pointers) and using JIT‑injected load barriers that fix references on first access, comparing this approach with G1 and Shenandoah and detailing ZGC 2.0 enhancements and known pitfalls.
This article explains ZGC’s evolution from an experimental feature in JDK 11 to a production‑ready collector in JDK 15, detailing its sub‑10 ms pause guarantee, memory‑mapping architecture, colored pointers, region layout, read barriers, and the multi‑phase concurrent collection process that together deliver low‑latency, high‑throughput garbage collection for Java applications.
The article thoroughly explains Android ART’s Concurrent Copying (CC) garbage collector—its terminology, correctness and progress requirements, engineering challenges, classic and Android‑specific algorithms, region‑based design with bump‑pointer allocation, performance benefits such as 32% lower heap usage and sub‑millisecond pauses, and its trade‑offs including doubled reserved heap space and migration overhead.
This article explains how Shenandoah OpenJDK's new concurrent thread‑stack processing, introduced in JDK 17, dramatically reduces garbage‑collection pause times to sub‑millisecond levels by using stack watermarks, and provides practical configuration guidance and benchmark results.
