[Vm-dev] unresponsive 64-bit Spur StackInterpreter, except...

[Eliot Miranda]

Hi All,

     I've a bit of a mystery and could do with suggestions of what to look
for.  The 64-bit Spur StackInterpreter VM on linux was working fine up
until a few months ago.  Now it doesn't respond to input, unless that is, I
put various breakpoints on various functions along the chain from aioPool
through to allocateInputEvent to signalExternalSemaphore to
doSignalExternalSemaphores when ... it can suddenly start working?!  I'm
planning to add a -debugeventchain flag or some such and if set write a
different character to stderr form each function along the chain so I can
see where the blockage is, but I fear heisenbugs; doing output could
perturb the system into working (given that gdb can perturb the system
also).  And I'm lazy so I wondered if anyone had a good idea.  I've thought
of it being thread-related but that's not the case as all event processing
in X11 happens on the main VM thread.  Anyway, I'm open to suggestions.
-- 
best,
Eliot
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