Mike (who really should know better :-) Yawn wrote:
> Dan Hollis ([log in to unmask]) wrote:
> : Does anyone know if there is a method in MPE to lock a program into memory
 
> There really isn't a (documented, supported, etc.) way to do this with
> Native Mode program files on MPE/iX.  I believe that the :ALLOCATE
> command still works for Compatibility Mode program files.
 
Just a reminder that the :ALLOCATE command has *no* effect whatsoever on
whether a program (or procedure) stays in memory or not.  It simply pre-loads
the program (opens the program file and resolves all the externals) so that
the first :RUN command of the program will be faster. If someone else is
already running a program, subsequent :RUNs of the program will start up at
the same speed whether the program is :ALLOCATEd or not.
 
The belief that :ALLOCATE somehow locks a program in memory is a common
mistake.  :ALLOCATEing a program does not use any memory whatsoever.  It does
use entries in system tables used for keeping track of CM resources though, so
there is a limit to how many programs you can :ALLOCATE before you run out of
some resource or other.
 
Dan's original message suggested that there was a POSIX interface on unix that
could be used to lock a file into memory.  Is this true?  I'd be kind of
surprised if the POSIX.1 standard included such an interface (and shouldn't we
then have it on MPE/iX too?).
 
G.