View source for Template:OS2API Example MustComplete

This example shows how a thread can notify the system to hold asynchronous exceptions during a section of code.
<code>
 #define INCL_DOSEXCEPTIONS   /* Exception values */
 #define INCL_DOSERRORS       /* Error values */
 #include <os2.h>
 #include <stdio.h>
 
 int main(VOID) {
   ULONG   ulNestLevel = 0;  /* Global variable tracking nesting
                                of DosEnterMustComplete calls     */
   APIRET  rc = NO_ERROR;    /* Return code                       */
 
   rc = DosEnterMustComplete(&ulNestLevel);
 
   if (rc != NO_ERROR) {
        printf("DosEnterMustComplete error: return code = %u\n",rc);
        return 1;
   } else {
        printf("ulNestLevel = %u\n",ulNestLevel);
   }
 
       /* ADD BLOCK OF CODE THAT MUST COMPLETE HERE... */
 
   rc = DosExitMustComplete(&ulNestLevel);
 
   if (rc != NO_ERROR) {
       printf("DosExitMustComplete error: return code = %u\n",rc);
       return 1;
   } else {
       printf("ulNestLevel = %u\n",ulNestLevel);
   }
 
   return NO_ERROR;
 }
</code>