Syntax
void _CRT_term(void); /* no header file - defined in run-time startup code */Description
By default, all DLLs call The Developer's Toolkit _DLL_InitTerm function, which in turn calls _CRT_term for you. However, if you are writing your own _DLL_InitTerm function (for example, to perform actions other than run time initialization and termination), and your DLL statically links to the C run-time libraries, you need to call _CRT_term from your _DLL_InitTerm function.
If your DLL contains C++ code, you must also call __ctordtorTerm before you call _CRT_term to ensure that static constructors and destructors are terminated correctly. __ctordtorTerm is defined in the run-time startup code as:
void __ctordtorTerm(void);
Once you have called _CRT_term, you cannot call any other library functions.
If your DLL is dynamically linked, you cannot call library functions in the termination section of your _DLL_InitTerm function. If your termination routine requires calling library functions, you must register the termination routine with DosExitList. Note that all DosExitList routines are called before DLL termination routines.
There is no return value for _CRT_term.
The following example shows the _DLL_InitTerm function from The Developer's Toolkit sample program for building DLLs, which calls _CRT_term to terminate the library environment.
#define INCL_DOSMODULEMGR
#define INCL_DOSPROCESS
#include <os2.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
/* _CRT_init is the C run-time environment initialization function. */
/* It will return 0 to indicate success and -1 to indicate failure. */
int _CRT_init(void);
#ifdef STATIC_LINK
/* _CRT_term is the C run-time environment termination function. */
/* It only needs to be called when the C run-time functions are statically */
/* linked. */
void _CRT_term(void);
#else
/* A clean up routine registered with DosExitList must be used if run-time */
/* calls are required and the run time is dynamically linked. This will */
/* guarantee that this clean up routine is run before the library DLL is */
/* terminated. */
static void cleanup(ULONG ulReason);
#endif
size_t nSize;
int *pArray;
/* _DLL_InitTerm is the function that gets called by the operating system */
/* loader when it loads and frees this DLL for each process that accesses */
/* this DLL. However, it only gets called the first time the DLL is loaded */
/* and the last time it is freed for a particular process. The system */
/* linkage convention MUST be used because the operating system loader is */
/* calling this function. */
unsigned long _DLL_InitTerm(unsigned long hModule, unsigned long
ulFlag)
{
size_t i;
APIRET rc;
char namebuf[CCHMAXPATH];
/* If ulFlag is zero then the DLL is being loaded so initialization should*/
/* be performed. If ulFlag is 1 then the DLL is being freed so */
/* termination should be performed. */
switch (ulFlag) {
case 0 :
/*******************************************************************/
/* The C run-time environment initialization function must be */
/* called before any calls to C run-time functions that are not */
/* inlined. */
/*******************************************************************/
if (_CRT_init() == -1)
return 0UL;
#ifndef STATIC_LINK
/********************************************************************/
/* A DosExitList routine must be used to clean up if run-time calls */
/* are required and the run time is dynamically linked. */
/********************************************************************/
if (rc = DosExitList(0x0000FF00|EXLST_ADD, cleanup))
printf("DosExitList returned %lu\n", rc);
#endif
if (rc = DosQueryModuleName(hModule, CCHMAXPATH, namebuf))
printf("DosQueryModuleName returned %lu\n", rc);
else
printf("The name of this DLL is %s\n", namebuf);
srand(17);
nSize = (rand()%128)+32;
printf("The array size for this process is %u\n", nSize);
if ((pArray = malloc(nSize *sizeof(int))) == NULL) {
printf("Could not allocate space for unsorted array.\n");
return 0UL;
}
for (i = 0; i < nSize; ++i)
pArray[i] = rand();
break;
case 1 :
#ifdef STATIC_LINK
printf("The array will now be freed.\n");
free(pArray);
_CRT_term();
#endif
break;
default :
printf("ulFlag = %lu\n", ulFlag);
return 0UL;
}
/* A non-zero value must be returned to indicate success. */
return 1UL;
}
#ifndef STATIC_LINK
static void cleanup(ULONG ulReason)
{
if (!ulReason) {
printf("The array will now be freed.\n");
free(pArray);
}
DosExitList(EXLST_EXIT, cleanup);
return ;
}
#endif
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