From:	MERC::"uunet!CRVAX.SRI.COM!RELAY-INFO-VAX" 28-JAN-1993 17:58:23.22
To:	info-vax@kl.sri.com
CC:	
Subj:	Re: Activating a sharable image

In article <1993Jan27.165530.4660@das.harvard.edu>, chen@speed.uucp (Lilei Chen) writes:

>Does someone on the net know how to call subroutines in a sharable image
>after a lib$find_image_symbol call?  What can one do with the the symbol
>value returned by that call?  An example in FORTRAN and/or C would be
>greatly appreciated.

Warning: the code fragment I am about to post is off the top of my head,
and therefore has never been tested!  It may not be exactly correct, but
the idea should be sound...

	program call_my_shareable_routine
	implicit none
	parameter shareable_image = 'MYSHR'	! assumes sys$share
	parameter gizmo_to_call   = 'MYROUTINE'
	integer*4 status,gizmo_addr,vector(0:2),arg1,arg2
	integer*4 lib$find_image_symbol,lib$callg
	status=lib$find_image_symbol(shareable_image,gizmo_to_call,gizmo_addr)
	if (.not. status) call lib$stop(%val(status))
	vector(0)=2		! This assumes that MYROUTINE takes two
	vector(1)=%loc(arg1)	! integer args.
	vector(2)=%loc(arg2)
	status=lib$callg(vec,proc) ! or should that be %val(proc)?
	if (.not. status) call lib$stop(%val(status))
	end

This is easier in C since you don't have to use LIB$CALLG.  For further
reference consult "A Guide to Writing Modular Library Procedures", "Linker
Reference Manual", and the LIB$ section of the RTL manual.

>Jim (xue@cfaft5.harvard.edu)
>

-Bill

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