[hbelusca] 61287: [NTVDM] Studying the "vddtest" example mentioned in revision 61283 allowed me to see that valid VDD DLL "handles" start at 1 and cannot be equal to zero. Add helper macros to conv...

Author: hbelusca
Date: Tue Dec 17 22:34:08 2013
New Revision: 61287

URL: http://svn.reactos.org/svn/reactos?rev=61287&view=rev
Log:
[NTVDM]
Studying the "vddtest" example mentioned in revision 61283 allowed me to see that valid VDD DLL "handles" start at 1 and cannot be equal to zero.
Add helper macros to convert from indices to handles. Fixes "vddtest" example.

Have fun at running it :)

Modified:
    branches/ntvdm/subsystems/ntvdm/vddsup.c

Modified: branches/ntvdm/subsystems/ntvdm/vddsup.c
URL: http://svn.reactos.org/svn/reactos/branches/ntvdm/subsystems/ntvdm/vddsup.c?...
==============================================================================
--- branches/ntvdm/subsystems/ntvdm/vddsup.c	[iso-8859-1] (original)
+++ branches/ntvdm/subsystems/ntvdm/vddsup.c	[iso-8859-1] Tue Dec 17 22:34:08 2013
@@ -29,9 +29,15 @@

/* PRIVATE VARIABLES **********************************************************/

+// TODO: Maybe use a linked list.
+// But the number of elements must be <= MAXUSHORT
 #define MAX_VDD_MODULES 0xFF + 1
-VDD_MODULE VDDList[MAX_VDD_MODULES] = {{NULL}}; // TODO: Maybe use a linked list.
-                                                // But the number of elements must be <= MAXUSHORT
+VDD_MODULE VDDList[MAX_VDD_MODULES] = {{NULL}};
+
+// Valid handles of VDD DLLs start at 1 and finish at MAX_VDD_MODULES
+#define ENTRY_TO_HANDLE(Entry)  ((Entry)  + 1)
+#define HANDLE_TO_ENTRY(Handle) ((Handle) - 1)
+#define IS_VALID_HANDLE(Handle) ((Handle) > 0 && (Handle) <= MAX_VDD_MODULES)

/* PRIVATE FUNCTIONS **********************************************************/

@@ -72,14 +78,14 @@
             setCF(0);

/* Retrieve the VDD name in DS:SI */
-            DllName = SEG_OFF_TO_PTR(getDS(), getSI());
+            DllName = (LPCSTR)SEG_OFF_TO_PTR(getDS(), getSI());

/* Retrieve the initialization routine API name in ES:DI (optional --> ES=DI=0) */
             if (getES() != 0 || getDI() != 0)
-                InitRoutineName = SEG_OFF_TO_PTR(getES(), getDI());
+                InitRoutineName = (LPCSTR)SEG_OFF_TO_PTR(getES(), getDI());

/* Retrieve the dispatch routine API name in DS:BX */
-            DispatchRoutineName = SEG_OFF_TO_PTR(getDS(), getBX());
+            DispatchRoutineName = (LPCSTR)SEG_OFF_TO_PTR(getDS(), getBX());

DPRINT1("DllName = '%s' - InitRoutineName = '%s' - DispatchRoutineName = '%s'\n",
                     (DllName ? DllName : "n/a"),
@@ -147,9 +153,9 @@
             /* Call the initialization routine if needed */
             if (InitRoutine) InitRoutine();

-            /* We succeeded */
+            /* We succeeded. RetVal will contain a valid VDD DLL handle */
             Success = TRUE;
-            RetVal = Entry;
+            RetVal  = ENTRY_TO_HANDLE(Entry); // Convert the entry to a valid handle

Quit:
             if (!Success)
@@ -172,12 +178,13 @@
         /* UnRegisterModule */
         case 1:
         {
-            WORD Entry = getAX();
+            WORD Handle = getAX();
+            WORD Entry  = HANDLE_TO_ENTRY(Handle); // Convert the handle to a valid entry

DPRINT1("UnRegisterModule() called\n");

/* Sanity checks */
-            if (Entry > MAX_VDD_MODULES || VDDList[Entry].hDll == NULL)
+            if (!IS_VALID_HANDLE(Handle) || VDDList[Entry].hDll == NULL)
             {
                 DPRINT1("Invalid VDD DLL Handle: %d\n", Entry);
                 /* Stop the VDM */
@@ -195,12 +202,13 @@
         /* DispatchCall */
         case 2:
         {
-            WORD Entry = getAX();
+            WORD Handle = getAX();
+            WORD Entry  = HANDLE_TO_ENTRY(Handle); // Convert the handle to a valid entry

DPRINT1("DispatchCall() called\n");

/* Sanity checks */
-            if (Entry > MAX_VDD_MODULES ||
+            if (!IS_VALID_HANDLE(Handle)    ||
                 VDDList[Entry].hDll == NULL ||
                 VDDList[Entry].DispatchRoutine == NULL)
             {