Re: Collecting markers with MPS

[Helmut Eller]

On Wed, Apr 24 2024, Eli Zaretskii wrote:

>> Yes, but only the programmers know which markers they no longer need.
>
> Sorry, I don't follow: how does the old GC detect dead markers?

I don't know the details. You'd have to read the code.  It's wizard
level.

> Why cannot a function we write do the same?

Because we would probably have to scan the heap for all potentially live
objects.

> I don't believe programmers will know which markers are no longer
> needed, primarily because most markers are completely unknown to
> programmers, Emacs creates them for its own purposes and never exposes
> them to Lisp.

Not all of course.  But those programmers who create markers like crazy
probably know it.  If they assume that markers are expensive then they
could better keep track of them (or not create them in the first place).

Helmut