[e-lang] Strange lock-ups with simple E program

[Mark Miller]

Hi Thomas, I haven't found the bug yet, but I have narrowed it down to
a race condition bug in the boot-comm system. Your same stress test,
with your

    def seedVat := seedVatAuthor(<unsafe>)

replaced by

    introducer.onTheAir()
    def seedVat := seedVatAuthor(<unsafe>).virtualize(introducer)

seems to never lock up. The only difference between these is that the
latter uses captp instead of boot-comm. In the boot comm case, the
form of lock up looks like a lost signal: all vats are quiescent
waiting for a message. I have also discovered many things that the bug
is not ;). Unfortunately, the clues so far seem to point to a
multi-threading race condition bug.

Unfortunately, I won't have time for further investigation for another
week. If you're blocked on this, might the above change be a useful
workaround for you?

-- 
Text by me above is hereby placed in the public domain

    Cheers,
    --MarkM