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rc = DosCreateMuxWaitSem( pszSemaphoreName, phmuxSemaphore, ulNumberOfRecords, pSemaphoreRecord, ulfAttributes );


PSZ pszSemaphoreName (input)
This is a pointer to the null-terminated string containing the semaphore name. Any named semaphore is considered shared. An unnamed semaphore will be created with pszSemaphoreName set to NULL. The name of a semaphore must be prefixed by \SEM32\, cannot be longer than 255 characters and must conform to the naming conventions of the file system.

PHMUX phmuxSemaphore (output)
This is a pointer to the HMUX that will get the handle to the new semaphore.

ULONG ulNumberOfRecords (input)
This is the number of records that are pointed to by pSemaphoreRecord. 64 is the maximum number of records allowable in a muxwait list.

PSEMRECORD pSemaphoreRecord (input)
This points to an array of SEMRECORD structures that are to be added to the muxwait list.

ULONG ulfAttributes (input)
This contains the attribute flags relevant to the creation of the semaphore. As of this writing three values may be set for ulAttributeFlags, they are DC_SEM_SHARED, DCMW_WAIT_ANY and DCMW_WAIT_ALL.


The following values can be returned
0NO_ERROROperation was successful.
6ERROR_INVALID_HANDLEError, The calling process must first have access to the shared semaphore in question before adding it to the muxwait list
8ERROR_NOT_ENOUGH_MEMORYError, Memory limit has been exceeded
87ERROR_INVALID_PARAMETERError, Unrecognized parameter
100ERROR_TOO_MANY_SEMAPHORESError, The value in ulNumberOfRecords cannot exceed 64
105ERROR_SEM_OWNER_DIEDError, The owner of a semaphore in the muxwait list has died before releasing it
123ERROR_INVALID_NAMEError, Name in pszSemaphoreName was rejected by file system
284ERROR_DUPLICATE_HANDLEError, The muxwait list pointed to by pSemaphoreRecord contains duplicate entries
285ERROR_DUPLICATE_NAMEError, Name in pszSemaphoreName is in use
290ERROR_TOO_MANY_HANDLESError, System limit of 65536 semaphores has been exceeded
292ERROR_WRONG_TYPEError, One or more entries in the muxwait list pointed to by pSemaphoreRecord is of the wrong type, MuxWait semaphores may not be added to a muxwait list, if the MuxWait semaphore is shared then only shared semaphores may be added to the list, If the MuxWait semaphore is private than the list may contain both shared and private semaphores

Include Info

#include <os2.h>

Usage Explanation

DosCreateMuxWaitSem creates a private or shared MuxWait semaphore. The usage count is incremented to 1. The process creating the semaphore does not need to open it also.

Relevant Structures


Sample Code

#define INCL_DOSSEMAPHORES #include <os2.h> UCHAR SemName; /* Pointer to the Semaphore Name */ PHMUX phmuxMySemaphore; /* pointer to my new semaphore handle */ ULONG ulAttribs= 0; /* Attribute flags, not used in this case */ SEMRECORD SemRecord; /* Record containing info about the sem */ /* I want to add to MySemaphore's list */ /* put the semaphore name in SemName */ strcpy(SemName,"\\SEM32\\MySem"); /* SemRecord is filled with appropriate information about */ /* the semaphore I wish to add to hmuxMySemaphore's list */ rc = DosCreateMuxWaitSem( SemName, phmuxMySemaphore, 1, /* 1 record to add */ &SemRecord, ulAttribs); if (rc != 0) { /* We got an error to take care of. */ }

See Also

DosAddMuxWaitSem, DosCloseMuxWaitSem, DosDeleteMuxWaitSem DosOpenMuxWaitSem, DosQueryMuxWaitSem, DosWaitMuxWaitSem


Joe Phillips - jaiger@eng2.uconn.edu


Last modified July 17/1996
Please send all errors, comments, and suggestions to: timur@vnet.ibm.com

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