DosEnterMustComplete

Provides entry into a section of code in which asynchronous exceptions are held.

Syntax

DosEnterMustComplete(pulNesting)

Parameters

pulNesting (PULONG) - output

A pointer to a value that is equal to the number of DosEnterMustComplete requests minus the number of DosExitMustComplete requests for the current thread.

Return Code

ulrc (APIRET) - returns

DosEnterMustComplete returns one of the following values:

• 0 NO_ERROR
• 650 ERROR_NESTING_TOO_DEEP

Remarks

Note: Do not make Presentation Manager calls from exception handlers.

DosEnterMustComplete notifies the system that the thread is entering a section of code in which asynchronous exceptions (signals and asynchronous process terminations) are to be held, rather than being immediately delivered to the thread.

Example Code

This example shows how a thread can notify the system to hold asynchronous exceptions during a section of 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;
}

Related Functions

• DosAcknowledgeSignalException
• DosExitMustComplete
• DosRaiseException
• DosSendSignalException
• DosSetExceptionHandler
• DosSetSignalExceptionFocus
• DosUnsetExceptionHandler
• DosUnwindException