Infinite Loop Prevention

Pluto can detect infinite loops by preventing too many successive iterations. This was implemented because game threads usually force users to call some sort of yield mechanism to return control to the game thread. In Pluto, you specify a hard bottleneck on iterations, then you specify a function pointer which should prevent ILP within the loop it's called in.

This will produce an error due to ILP:

while true do

end

This will not, with correct configuration:

while true do
    yield()
end

If your scheduling system calls coroutine.yield at least once per tick, configuring the ILP mechanism can be as simple as defining PLUTO_ILP_ENABLE. In any case, Pluto's configuration file (luaconf.h) is worth a look at, especially to properly configure this feature.

info

This is a very simple mechanic. It has no performance overhead & it's lightweight. However, the compromise for this was coverage. This will reliably prevent most user error, however malicious users can find a way to block a thread still. For example, any forward jump will prevent the mechanism from breaking a loop. This can be exploited, so don't rely on this for security.