Infinite loops on uncaught exceptions #58

cwebber commented 2022年04月27日 23:56:02 +02:00 (Migrated from github.com)

In switching guile-goblins from Fibers 1.0 to 1.10, I noticed that when exceptions occured, schedulers suddenly stopped working but also my cpu would shoot up to 100%. That's strange, that shouldn't happen, what gives?

I did a git-bisect against fibers to try to figure out where this started. The issue is introduced in 84addfbfc6. I haven't checked for sure, but I'm pretty certain that what's happening is that where the scheduler previously was catching the exception in the individual task but the scheduler would continue looping, now the scheduler is breaking and not continuing on an individual error. Thus, it isn't feeding anything to the individual fibers, which start spin locking madly.

In switching [guile-goblins](https://gitlab.com/spritely/guile-goblins) from Fibers 1.0 to 1.10, I noticed that when exceptions occured, schedulers suddenly stopped working but also my cpu would shoot up to 100%. That's strange, that shouldn't happen, what gives? I did a git-bisect against fibers to try to figure out where this started. The issue is introduced in 84addfbfc69e7dea63c4b9b08656d052043bcecf. I haven't checked for sure, but I'm pretty certain that what's happening is that where the scheduler previously was catching the exception in the individual task but the scheduler would continue looping, now the scheduler is breaking and *not* continuing on an individual error. Thus, it isn't feeding anything to the individual fibers, which start spin locking madly.

cwebber commented 2022年04月28日 21:30:20 +02:00 (Migrated from github.com)

One option is simply to revert 84addfbfc6. Maybe @wingo might not like this; it fixes it, but it re-introduces whatever performance issue the commit was meant to address.

One option is simply to revert 84addfbfc69e7dea63c4b9b08656d052043bcecf. Maybe @wingo might not like this; it fixes it, but it re-introduces whatever performance issue the commit was meant to address.

aconchillo commented 2022年04月28日 23:26:49 +02:00 (Migrated from github.com)

IMO, stability is always preferred over performance.

IMO, stability is always preferred over performance.

wingo commented 2022年04月29日 15:31:23 +02:00 (Migrated from github.com)

Do you have a test case?

Do you have a test case?

aconchillo commented 2022年06月04日 07:17:47 +02:00 (Migrated from github.com)

@cwebber Probably completely unrelated, but I'm wondering if this commit github.com/wingo/fibers@c25dcb9cc4 would fix the issue you are seeing. Available in Fibers 1.1.1.

@cwebber Probably completely unrelated, but I'm wondering if this commit https://github.com/wingo/fibers/commit/c25dcb9cc4b5b977474ffe555b40ce2f1d0d1edc would fix the issue you are seeing. Available in Fibers 1.1.1.

wingo commented 2023年06月08日 10:29:43 +02:00 (Migrated from github.com)

Pretty sure this is fixed via #76, which is now in Guile main. Christine can you give a try with Guile from git and see if you are still having issues? Or otherwise close this one if you think it is fixed.

Pretty sure this is fixed via #76, which is now in Guile `main`. Christine can you give a try with Guile from git and see if you are still having issues? Or otherwise close this one if you think it is fixed.