View source for DosAddMuxWaitSem

DosAddMuxWaitSem adds an event semaphore or a mutex semaphore a MuxWait semaphore list.

== Syntax ==
 DosAddMuxWaitSem( ''hmuxSemaphore'', ''pSemRecord'' )

=== Parameters ===
;HMUX ''hmuxSemaphore'' (input):The handle of the MuxWait semaphore to which another semaphore will be added.
;PSEMRECORD ''pSemRecord'' (input):The address of a SEMRECORD to be added to the specified MuxWait semaphore.
 
=== Returns ===
 APIRET rc
The following values can be returned:
*0 NO_ERROR - Operation was successful.
*6 ERROR_INVALID_HANDLE - Error, The value in ''hmuxSemaphore'' does not point to a valid semaphore, The calling process must first have access to the semaphore in question
*8 ERROR_NOT_ENOUGH_MEMORY - Error, The system memory limit has been exhausted
*87 ERROR_INVALID_PARAMETER - Error, One or more of the parameters contains an illegal value.
*100 ERROR_TOO_MANY_SEMAPHORES - Error, The system limit of 64 semaphores has been exceeded for this MuxWait semaphore.
*105 ERROR_SEM_OWNER_DIED - Error, The owner of the MuxWait semaphore specified has terminated.
*284 ERROR_DUPLICATE_HANDLE - Error, The semaphore referred to in ''pSemRecord'' has already been added to the specified MuxWait semaphore.
*292 ERROR_WRONG_TYPE - Error, The semaphore referred to in ''pSemRecord'' is of a different 
type than those already in the list for ''hmuxSemaphore''.

=== Gotchas ===
All processes that have access to a shared MuxWait semaphore must also have access to the event/mutex semaphore that is to be added to the MuxWait list.
If a process does not have access to this semaphore then it will unblock and return the error ERROR_INVALID_HANDLE. DosAddMuxWaitSem will NOT return an error in this case. The processes wishing to gain access to the MuxWait semaphore will return errors until proper access has been obtained.

=== Sample Code ===
<PRE>
#define INCL_DOSSEMAPHORES
#include <os2.h>

HMUX  hmuxMySemaphore;     /* MySemaphore handle */
SEMRECORD SemRecord;       /* Record containing info about the sem */
                           /* I want to add to MySemaphore's list */

	/* access is gained to the semaphore in question */
	/* either by DosCreateMuxWaitSem ... */
	/* ... or by DosOpenMuxWaitSem */
	/* its handle is placed in hmuxMySemaphore */

	/* SemRecord is filled with appropriate information about */
	/* the semaphore I wish to add to hmuxMySemaphore's list */

	rc = DosAddMuxWaitSem(hmuxMySemaphore, &SemRecord);

	if (rc != 0)
	{
	  /* We got an error to take care of. */
	}
</PRE>

=== See Also ===
*[[DosCloseMuxWaitSem]]
*[[DosCreateMuxWaitSem]]
*[[DosDeleteMuxWaitSem]]
*[[DosOpenMuxWaitSem]]
*[[DosQueryMuxWaitSem]]
*[[DosWaitMuxWaitSem]] 

[[Category:Dos]]