From:	MERC::"uunet!WKUVX1.BITNET!MacroMan" 10-FEB-1993 01:25:15.28
To:	MACRO32@WKUVX1.BITNET
CC:	
Subj:	Re: Problems with sharable library

I wrote
>> G'day,
>>      I'm posting this for one of our developers.
>>
>> He has a problem with a program he is developing that links against a
 sharable
>> library.
>> In his words
>>
>> | The program I am writing fails to run with the MDLC$LIB library (see below
 for
>> |the error messages produced and the LINK commands). It appears that the
>> |MDLC$LIB library is meant to be mapped at location 819712 (ie. 000C8200
 hex),
>> |but when I looked at the map file, this location appeared to be free.
>> |Have you seen this problem before, and do you know of a workaround,

Thanks to all who replied. The answer we found was to

Create a new object module which is linked at the next address above the
MDLC$LIB library. The purpose is top act as a "guard" page" to forces all other
sharable images to be mapped above it, and hench above MDLC$LIB as well. Thus
the memory overlap problem is overcome. The source for the guard page, and the
link command is below

        #module         MOSCAD_GUARD_PAGE
        static unsigned long guard_page_memory = 0'

LINK

was
> |LINK/DEBUG/MAP MOSCAD_CHECK_TIMES + ODDLSRC:CATAGORY + SYS$INPUT/OPT
> |     USER:[ITN.LIB]ITNLIB.OLB
> |     CLUSTER=DDR,512,,MDLC$DEVICE:[MTS_THREAD]DDR_SPC.OBJ
> |     CLUSTER=APP,819712,,MDLC$LIB/SHARE
> |     SYS$SHARE:VAXCRTL.EXE/SHARE

is now
   LINK/DEBUG/MAP MOSCAD_CHECK_TIMES + ODDLSRC:CATAGORY + SYS$INPUT/OPT
        USER:[ITN.LIB]ITNLIB.OLB
        CLUSTER=DDR,512,,MDLC$DEVICE:[MTS_THREAD]DDR_SPC.OBJ
        CLUSTER=APP,819712,,MDLC$LIB/SHARE
        CLUSTER=GUARD,965120,,MOSCAD_GUARD_PAGE.OBJ
        SYS$SHARE:VAXCRTL.EXE/SHARE

>Jonas Lindholm                         Internet: jlh@seb.se
asks:
>       Why do you want the sharable images to be mapped at a specific address?

Good question, The answer is we don't, we are stuck using VENDOR supplied
routines. (and vendors who don't know).

                        Regards Richard Farnsworth

Internet:     richard@mits.com.au    PSI Mail:     psi%0505238730004::richard
Alternate:    richard%mits.com.au@ucsvc.ucs.unimelb.edu.au

The King sent all his men
To find a rhyme for W
But when they couldn't he said
I'm sorry to trouble you