en:docs:fapi:dosfreemodule

This is part of Family API which allow to create dual-os version of program runs under OS/2 and DOS

Note: This is legacy API call. It is recommended to use 32-bit equivalent

2021/09/17 04:47 · prokushev · 0 Comments
2021/08/20 03:18 · prokushev · 0 Comments

DosFreeModule

This call frees the reference to a dynamic link module for a process. When the dynamic link module is no longer needed by any process, the module is freed from system memory.

Syntax

DosFreeModule (ModuleHandle)

Parameters

  • ModuleHandle (HMODULE) - input : Handle returned by DosLoadModule.

Return Code

rc (USHORT) - return:Return code descriptions are:

  • 0 NO_ERROR
  • 6 ERROR_INVALID_HANDLE
  • 12 ERROR_INVALID_ACCESS
  • 95 ERROR_INTERRUPT

Remarks

The module identified by the handle must be loaded through DosLoadModule. An error is returned if the handle is invalid.

If any exit list routines were registered as a result of this module being loaded, the module may not be freed and ERROR_INVALID_ACCESS may be returned.

When DosFreeModule returns to the caller, the module handle is no longer valid and is not used to reference the dynamic link module. Procedure entry addresses returned for this module are no longer valid and cause a protection fault if they are invoked.

Bindings

C

#define INCL_DOSMODULEMGR
 
USHORT  rc = DosFreeModule(ModuleHandle);
HMODULE ModuleHandle;  /* Module handle */
 
USHORT  rc;            /* return code */

MASM

EXTRN  DosFreeModule:FAR
INCL_DOSMODULEMGR   EQU 1
 
PUSH   WORD    ModuleHandle  ;Module handle
CALL   DosFreeModule
 
Returns WORD

Example

This example tries to load module ABCD. The system searches LIBPATH. If unsuccessful, the system tries to load the module from the program's directory (in case the user forgot to update LIBPATH).

#define INCL_DOSMODULEMGR
 
#define MODULE_NAME "abcd"
#define FULL_MODULE_NAME "\\nifty\\abcd.dll"
 
CHAR    LoadError[100];
HMODULE ModuleHandle;
USHORT  rc;
 
   if (DosLoadModule(LoadError,              /* Object name buffer */
                     sizeof(LoadError),      /* Length of object name buffer */
                     MODULE_NAME,            /* Module name string */
                     &ModuleHandle) == 2)    /* Module handle */
      rc = DosLoadModule(LoadError,          /* Object name buffer */
                         sizeof(LoadError),  /* Length of object name buffer */
                         FULL_MODULE_NAME,   /* Module name string */
                         &ModuleHandle);     /* Module handle */
   rc = DosFreeModule(ModuleHandle);         /* Module handle */