Accepting jdwp connection early enough to debug Graal startup with -Xcomp

Gary Frost frost.gary at
Wed Aug 28 09:52:56 UTC 2019

Have been away from Graal since 'Sumatra' days so forgive the 'n00b'

I have been patching Graal's startup (to mutate some nodes) and noticed
that when I run with a standard jdwp connector configured thusly..


By the time my debug connection has attached I have 'missed' all the Graal
setup 'goodness' :)

Admittedly I am running with -Xcomp  (oh and this is OpenJDK 11)

Re-reading the jdwp specs, I note that the contract is only that the VM
will halt and wait for connections prior to entering my applications'
main(). So no bug here, I just wish I could halt earlier ;)

How (if there is a way) do you guys get to debug startup with -Xcomp?

Is there a trick? that I am missing to halt as early as possible (I
understand there is an implied race)


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