Re: probes

[Marcus G. Daniels]

>>>>> "ST" == Sven N Thommesen <address@hidden> writes:

ST> Would it be a major deal to add functionality to VarProbes so that
ST> the user program may ask (a) whether the data content of any of
ST> the probed values has been changed

This is hard.  In C-like languages implementing a write-barrier means
1) trapping access to memory locations with the help of a system call
like mprotect and, once trapped, inverting the address back to the
symbol using available data or 2) enhancing the compiler to do it for you.

However, if one builds a language (like Ferdinando Villa has with IMT), then
everything is trackable, because all changes to the state of the
simulation must go through the simulator interfaces.

ST> I have had people ask me why it is that they can stop a sim,
ST> change parameter values in probe windows, and restart, but the
ST> program does not seem to take account of the new values.

The usual answer, as I'm sure you know, is that some ivars are only processed
at initialization type, e.g. -build{Objects,Actions}.


                  ==================================
   Swarm-Support is for discussion of the technical details of the day
   to day usage of Swarm.  For list administration needs (esp.
   [un]subscribing), please send a message to <address@hidden>
   with "help" in the body of the message.