[Chicken-users] Question again on heap mutation from signal handlers.

[Jörg F . Wittenberger]

Kon (or maybe Felix)

On Sep 1 2011, Kon Lovett wrote:

> Probably of no use to you but … When I added all the extra unix
> (Chicken v2 I think) signals stuff I figured (ha) that a Scheme
> signal handler could only perform operations that accessed existing
> structures, no heap mutation. I used handlers that basically only
> set flags.

Is there a way to verify that signal handlers can not allocate
on the heap?

As far as I understand runtime.c this should be true.
But it's fairly complicated to reason here.
It would be very, very helpful to be sure about that one.

Since my eat-all-mem issue was gone all too suddenly with yet
another git update (the one with the larger update to types.db),
I'm afraid it might be a false positive.

And there are the downsides of the approach I've take to
get around this (possibly fake) issue.  Not only makes
it the interrupt latency a little larger (since what it tries
to do is to wait for gc to finish); I've used to have a signal
handler, which would write a thread listing into the log file.
This has been extraordinary reliable even when I managed to
mess up the thread system.  No longer avail.

Now I tried to re-enable the old handler invocation to confirm
that the old issue would come back.
So far it did not - which is confusing.

Thanks a lot

/Jörg