Re: Some experience with the igc branch

[Pip Cet]

"Eli Zaretskii" <eliz@gnu.org> writes:

>> Date: Fri, 27 Dec 2024 17:26:04 +0000
>> From: Pip Cet <pipcet@protonmail.com>
>> Cc: Gerd Möllmann <gerd.moellmann@gmail.com>, stefankangas@gmail.com, 
>> ofv@wanadoo.es, emacs-devel@gnu.org, eller.helmut@gmail.com, acorallo@gnu.org
>>
>> "Eli Zaretskii" <eliz@gnu.org> writes:
>>
>> >   - Concurrent.  The GC runs in its own thread.  There are no explicit
>> >     calls to start GC, and Emacs doesn't have to wait for the GC to
>> >     complete.
>> >
>> > Pip says this is not true?
>>
>> I'm a bit confused.  Right now, on scratch/igc, on GNU/Linux, for Emacs
>> in batch mode, it isn't technically true.
>
> Then how do you explain the fact that, when igc does GC (as evidenced
> by the echo-area messages if you enable garbage-collection-messages),
> Emacs is not stopped, as it happens with the old GC?  If GC is done on
> the main thread, it means the main thread should stop while GC is in
> progress, and yet I don't see it stopping.  What did I miss?

I have no idea how you "see it stopping".  Incremental GC happens in
increments, which take less time individually than a full GC cycle
would, so interactions are smoother.  Separate threads are certainly not
required for that (neither is incremental GC, in all cases;
mark-and-sweep collectors can be interrupted, discarding the mark bits).

Pip