This example creates two semaphore record lists, with two event semaphores in each. It then creates a muxwait semaphore with the first semaphore record list, and it adds the second list later using DosAddMuxWaitSem.

#define INCL_DOSSEMAPHORES   /* DOS semaphore values */
#define INCL_DOSERRORS       /* DOS error values */
#include <os2.h>
#include <stdio.h>

int main(VOID) {
 HMUX      hmuxHandAny = NULLHANDLE;      /* Muxwaithandle */
 HEV       hev[5]      = {0};             /* Event semaphores */
 SEMRECORD apsr[5]     = {{0}};           /* Semaphore records */
 APIRET    rc          = NO_ERROR;        /* Return code */
 ULONG     ulLoop      = 0;               /* Loop count */
 ULONG     ulSem       = 0;

for (ulLoop = 0; ulLoop < 5; ulLoop++) {
    rc = DosCreateEventSem((PSZ) NULL,
                           &hev[ulLoop],
                           0,
                           FALSE);
    if (rc != NO_ERROR) {
      printf("DosCreateEventSem error:  return code = %u\n", rc);
      return 1;
    }
    apsr[ulLoop].hsemCur = (HSEM) hev[ulLoop],
    apsr[ulLoop].ulUser = 0;
} /* endfor */

rc = DosCreateMuxWaitSem((PSZ) NULL,
                         &hmuxHandAny,
                         5L,              /* Number of semaphores in list */
                         apsr,            /* Semaphore list */
                         DCMW_WAIT_ANY);  /* Wait for any semaphore */
    if (rc != NO_ERROR) {
      printf("DosCreateMuxWaitSem error:  return code = %u\n", rc);
      return 1;
    }

rc = DosWaitMuxWaitSem(hmuxHandAny,
                       SEM_IMMEDIATE_RETURN,
                       &ulSem);           /* No semaphores have been posted, so
                                             we should see a timeout below...    */
    if (rc != ERROR_TIMEOUT) {
      printf("DosWaitMuxWaitSem error:  return code = %u\n", rc);
      return 1;
    }

rc = DosDeleteMuxWaitSem(hmuxHandAny, apsr[0].hsemCur);
    if (rc != NO_ERROR) {
      printf("DosDeleteMuxWaitSem error:  return code = %u\n", rc);
      return 1;
    }
rc = DosCloseMuxWaitSem(hmuxHandAny);
     if (rc != NO_ERROR) {
       printf("DosCloseMuxWaitSem error: return code = %u\n", rc);
       return 1;
     }

return NO_ERROR;
}