From: "Salvador Eduardo Tropea (SET)" <salvador AT inti DOT edu DOT ar>
To: djgpp AT delorie DOT com
Subject: Problems with CWSDPMI and nested app.
Date: Wed, 26 Jun 1996 14:19:43 +0300 (GMT)
Message-ID:  <9606261419.aa10878@ailin.inti.edu.ar>

Hi everybody:

  I have a problem with CWSDPMI, seems to be a bug: When i use the function
__dpmi_segment_to_descriptor in a nested application (a DJGPP v2 app called
by another DJGPP v2 app) the function lies (don't make your job but says that
all is OK).

  Code to reproduce the problem:

>>>>>> Batch to make all:
@Echo Creating offending code
@gcc -O2 -Wall -opp  -g3 pp.c
@gcc -O2 -Wall -opp2 -g3 pp2.c
pp2
@symify pp
>>>>>> Batch to make all, end

>>>>>> PP.C
#include <stdio.h>
#include <dpmi.h>
#include <sys\farptr.h>

int main(void)
{
 int sel=__dpmi_segment_to_descriptor(0xA000);

 printf("Descriptor: %d\n",sel);
 _farsetsel(sel);
 return 0;
}
>>>>>> PP.C, end

>>>>>> PP2.C
#include <stdlib.h>

int main(void)
{
 system("pp");
 system("pp");
 return 0;
}
>>>>>> PP2.C, end

  All works OK under Win3.1 (but there are more serious bugs on this DPMI
server ;), under MS-DOS 6.20 with CWSDPMI the second call to "PP" gets the
same descriptor but when i charge this value to the register >K-Bum<. The
problem is that the second call to __dpmi_segment_to_descriptor returns the
descriptor but not allocates any descriptor in the LDT (i see this using
FSDB, thanks Morten!!!). Note: When the first "PP" exits the entry allocated
by __dpmi_segment_to_descriptor is automatically liberated.

  Here are some details of the platform:

OS:  MS-DOS 6.20
CPU: Cyrix 5x86
DPMI server:
CWSDPMI V0.90+ (r1) or CWSDPMI V0.90+ (r2).

Config.SYS:

LASTDRIVE=Z
DEVICE=\DOS6\HIMEM.SYS /TESTMEM:OFF
DEVICE=\DOS6\EMM386.EXE NOEMS D=64
BUFFERS=30
FILES = 60
FCBS=16,0
DOS=UMB
DOS=HIGH
DEVICEHIGH =\DEV\ATAPI_CD.SYS /H /D:SONY_000
SHELL=C:\DOS6\COMMAND.COM C:\DOS6\ /E:1024 /p
BREAK=ON
COUNTRY=034,,C:\DOS6\COUNTRY.SYS
DeviceHigh = C:\DOS6\Ansi.SYS
DEVICEHIGH=C:\DOS6\RAMDRIVE.SYS 4096 /E
STACKS=18,512

Autoexec.BAT:

LH e:\tvgautil\utility\setreg
e:\tvgautil\utility\smonitor 0
call d:\tbav\TBSTART.BAT
@Echo AutoExec.BAT
@Echo
@Echo Sound Blaster
SET SOUND=C:\SB16
SET BLASTER=A220 I5 D1 H5 P330 T6
C:\SB16\SB16SET /M:220 /VOC:220 /CD:220 /MIDI:220 /LINE:220 /TREBLE:0
C:\SB16\SBCONFIG.EXE /S
LH C:\DOS6\SMARTDRV.EXE /N 4096
SET PATH=C:\WINDOWS;C:\DOS6;C:\DJ\BIN;C:\UTILES;C:\BorlandC\Bin;C:\BLINKER3;C:\IDI\Cli5\Bin;D:\Micros\Keil\Bin
PATH=%PATH%;d:\tbav
Set C51Lib=D:\Micros\Keil\Lib
Set C51Inc=D:\Micros\Keil\Inc
PROMPT $P$G
Set Temp=F:
SET OBJ=C:\IDI\CLI5\Obj;C:\BLINKER3\OBJ;C:\Idi\Cli5\ObjSis
SET PLL=C:\IDI\CLI5\PLL
SET LIB=C:\BLINKER3\LIB;C:\Lite286\BC3\Lib;C:\Idi\Cli5\Lib
SET INCLUDE=C:\Idi\C5\Include;C:\Blinker3\C;C:\Idi\Cli5\Include
SET BASES=C:\CONFIGUR
SET SONIDOS=C:\CONFIGUR
Rem DJ:
Set DJGPP=c:/dj/djgpp.env
Set TMPDIR=f:
Set GO32=driver c:/dj/drivers/tridnt89.grd gw 800 gh 600
LH C:\UTILES\MOUSE /L6
LH C:\BIN\MSCDEX.EXE /D:SONY_000 /M:10
Rem Acentuador castellano MADE IN ARGENTINA
LH Acent
C:\norton\NC


********************************************************************************
Salvador Eduardo Tropea (SET) - salvador AT inti DOT edu DOT ar
Work: INTI (National Institute of Industrial Technology) Sector: ICE 
(Electronic Control & Instrumentation)
Post (Home): Curapaligue 2124 - Caseros (1678)- Buenos Aires - Argentina