Garbage Collection and Threads

Question

AFAIK when a GC is doing its thing the VM blocks all running threads -- or at least when it is compacting the heap. Is this the case in modern implementions of the CLR and

Answer 1

There are a number of GC algorithms available with Java, not all of which block all running threads. For example, you can use -XX:+UseConcMarkSweepGC which runs concurrently with the app (for collection of the tenured generation).