[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: TRAP #1 from TRAP #2?
|It's perfectly all right to call Gemdos (trap #1) from the AES or
|VDI (trap #2). Traps don't count as interrupts for the purposes
|of the Compendium warning. The reason for the dire warnings in
|the Compendium is that Gemdos is not re-entrant, so if it is called
|from itself the system will crash. This can't happen in the sequence
| user -> AES -> Gemdos
|but could in the sequence
| user -> Gemdos -> interrupt (e.g. vertical blank) -> Gemdos
I know this is safe to call Gemdos or VDI from AES (without this,
UserDef objects won't be possibles!)..
But I think AES is called sometime from interrupt, for the timer
stuff.. I don't think AES call user functions at this moment, but
this is not sure..
Stephane Boisson | 11, rue de la Garenne | Falcon030/MiNT, MacIIci, Un*x
email@example.com | 92310 Sevres FRANCE | TCP/IP, XWindow, C, 680x0
http://www.worldnet.net/~boisson/ - http://www.axene.com/
"On a souvent besoin de cogner sur un plus petit que soi"