DosExitMustComplete: Difference between revisions

Revision as of 22:57, 19 December 2016

Description

Provides exit from a section of code in which asynchronous exceptions are held.

Syntax

#define INCL_DOSEXCEPTIONS
#include <os2.h>

PULONG    pulNesting;  /*  Pointer to the nesting level. */
APIRET    ulrc;        /*  Return Code. */

ulrc = DosExitMustComplete(pulNesting);

Parameters

pulNesting (PULONG) - output: Pointer to the nesting level.

The nesting level is equal to the number of DosEnterMustComplete requests minus the number of DosExitMustComplete requests for the current thread.

Return Code

ulrc (APIRET) - returns

DosExitMustComplete returns one of the following values:

0 NO_ERROR
300 ERROR_ALREADY_RESET

Remarks

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

DosExitMustComplete notifies the system that the calling thread is leaving a section of code in which any asynchronous exceptions (signals and asynchronous process terminations) that may have occurred were 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;
    }

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