WinWaitMuxWaitSem waits for a muxwait semaphore to clear or for a Presentation Manager message.

#define INCL_WINMESSAGEMGR
#include <os2.h>

HMUX      hmux;       /*  The handle of the muxwait semaphore to wait for. */
ULONG     ulTimeout;  /*  Time-out in milliseconds. */
PULONG    pulUser;    /*  Pointer to receive the user field. */
APIRET    ulrc;       /*  Return Code. */

ulrc = WinWaitMuxWaitSem(hmux, ulTimeout,
         pulUser);