> With the current design, it isn't possible though because the code objects are modified in place so if co_quickened is freed the VM still tries to execute the copied instructions.

Or the cleanup code could also restore co_firstinstr and other things that are set by quickened (the co_quickened flag and what else?).

Kumar, I'm not sure I follow your concerns about the bootstrap working differently on Windows than on Unix. Is the problem that on Unix the bootstrap interpreter is linked without deepfreeze.c so there is no definition of the symbol _Py_Deepfreeze_Fini? In that case, you can probably just add a dummy one to _bootstrap_python.c.