Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

◄Function Group►  ◄Overview►                          ◄Up► ◄Next► ◄Previous►
────────────────────────────────────────────────────────────────────────────
 
#define INCL_WINMESSAGEMGR
 
USHORT WinMsgMuxSemWait(pisemCleared, pmxsl, lTimeOut);
PUSHORT pisemCleared;   /* address of variable that receives index number */
PVOID pmxsl;            /* address of structure with semaphore list       */
LONG lTimeOut;          /* length of time to wait                         */
 
The WinMsgMuxSemWait function waits for one or more of the specified
semaphores to clear. This function checks the specified list. If any of the
semaphores are clear, the function returns. Otherwise, the function waits
until the specified time elapses or until one of the semaphores in the list
clears.
 
Parameter     Description
────────────────────────────────────────────────────────────────────────────
 
pisemCleared  Points to the variable that receives the index number of the
              most recently cleared semaphore.
 
pmxsl         Points to the MUXSEMLIST structure containing a semaphore list
              that defines the semaphores to be cleared. The semaphore list
              consists of one or more semaphore handles.
 
lTimeOut      Specifies how long to wait for the semaphores to become
              available. If the value is greater then zero, this parameter
              specifies the number of milliseconds to wait before returning.
              If the value is SEM_IMMEDIATE_RETURN, the function returns
              immediately. If the value is SEM_INDEFINITE_WAIT, the function
              waits indefinitely.
 
Return Value
 
The return value is zero if the function is successful. Otherwise, it is an
error value, which may be one of the following:
 
     ERROR_EXCL_SEM_ALREADY_OWNED
     ERROR_INTERRUPT
     ERROR_INVALID_EVENT_COUNT
     ERROR_INVALID_HANDLE
     ERROR_INVALID_LIST_FORMAT
     ERROR_SEM_TIMEOUT
     ERROR_TOO_MANY_MUXWAITERS
 
Comments
 
This function is identical to the DosMuxSemWait function with the following
exceptions: Window messages sent via the WinSendMsg function by another
thread may be received; the function can wait for 15 semaphores
simultaneously (DosMuxSemWait can wait for 16).
 
This function should be used to wait for a semaphore when the semaphore
owner may need to issue a WinSendMsg function (or another Win function that
implicitly issues a WinSendMsg function) before clearing the semaphore.
 
See Also
 
DosMuxSemWait, WinMsgSemWait, WinSendMsg, MUXSEMLIST
 
                                      ♦