It seems there is problem linking the procedure addresses between Oxygen and ThinBASIC
I think this code worked fine before, but now I get zeros for both code pointers. I am not sure whether it is issue in Oxygen or ThinBASIC, but I am posting it here to not forget about it:
DWord oxySumTwo, oxyFinish
callbackCode = "
Function Oxygen_SumTwo( Byval a As Long, Byval b As Long) As Long At #oxySumTwo
Sub Oxygen_Finish() At #oxyFinish
If Len(O2_ERROR) Then
MsgBox 0, O2_ERROR, "JIT compilation failed"
MsgBox 0, "oxySumTwo: " + oxySumTwo + $CRLF +
"oxyFinish: " + oxyFinish,
"The values should be non-zero"