The use of read barriers are exactly the same technique that Azul does with Zing, it’s “pauseless” GC. This allows for concurrent heap compaction, at the cost

The use of read barriers are exactly the same technique that Azul does with Zing, it’s “pauseless” GC. This allows for concurrent heap compaction, at the cost of throughput. Azul used to sell commercial “java machines”, with hardware support for the barriers.