[kelseyfrog]

There are none, or you're not aware of their existence?

[pebal]

There are no production implementations of GC algorithms that don't stop the world at all. I know this because I have some expertise in GC algorithms.

[kelseyfrog]

I'm curious why you don't consider C4 to be production grade

[pebal]

Azul C4 is not a pauseless GC. In the documentation it says "C4 uses a 4-stage concurrent execution mechanism that eliminates almost all stop-the-world pauses."

[kelseyfrog]

Except the documentation says

> C4 differentiates itself from other generational garbage collectors by supporting simultaneous-generational con- currency: the different generations are collected using concurrent (non stop-the-world) mechanisms

[pebal]

It doesn't matter at all. C4 uses STW.

[kelseyfrog]

I wish I could have learned more from this interaction than it doesn't matter.