Zero-pause GC implementation

[fabianoliver]

I hope this is the right place to ask this. This question has been on my mind out of sheer curiosity for a while.

Predictability of latency is quite a concern for various applications. In such cases, people tend to either go out of their way with oftentimes rather.. hacky solutions to partially mitigate this issue, or at times avoid C# (and many other GC'ed languages) entirely.
At the same time, the concept of pause-free collectors seems to be theoretically possible. Java has a fairly popular implementation with Azul's C4, and as far as I remember the outline of their approach has been published as well.

I'm curious as to why this doesn't seem to exist in the C# ecosystem. I would imagine there being significant economic interest behind this, given several industries from finance all the way to the gaming industry would have significant stakes.

Is there anything specific to dotnet/the CLR that would render an implementation impossible?
Or has there simply not been enough interest/incentivization for this to be implemented, given it's of course a very hard thing to get right? Has it ever been discussed by the team - and if so, were there any conclusions that you'd be willing to share - both in terms of whether it's feasible at all, as well as the likelihood of a standard implementation?

[svick]

Previous discussion: #49059.

[danmoseley]

@Dotnet/area-gc-coreclr

[danmoseley]

Hmm, that doesn't exist - probably should (@mangod9?)
@Maoni0 then

[teo-tsirpanis]

BTW it's @dotnet/gc.