Java - Memory Model & GC
Memory Model & Garbage Collection
Java Memory Model (JMM)
- Happens-before: ordering and visibility guarantees.
- Synchronization establishes happens-before relationships.
- volatile: visibility, not atomicity.
Garbage Collection
- Generational hypothesis: most objects die young.
- Common collectors: G1 (default), ZGC (low-latency), Shenandoah (low-pause).
Architect note: Tune GC only when profiling indicates memory/latency pressure; start with defaults for LTS JDKs.