On Sat, 10 Jun 2017 16:41:16 -0700, Charles Mills <[email protected]> wrote:
>A refreshable program may modify itself, right? REFR does not say "I don't >modify myself" it says "you can reload me if you want." Almost >the same >thing, but not quite. The key, I think, is that the system may reload the program at _any_ time, even on the instruction immediately after it modifies itself. Therefore, there is no _safe_ way for a refreshable program to do such a modification, as it cannot make any assumptions about how long the modification will survive. At least a RENT program can use serialization to allow safe modifications (FSVO "safe"), but a REFR program doesn't have that ability. -- Walt ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
