pszName (PSZ) - input

Pointer to the ASCIIZ name of the semaphore.

Semaphore names are validated by the file system, and must include the prefix \SEM32\. A maximum of 255 characters is allowed. If these requirements are not met, ERROR_INVALID_NAME is returned. If the semaphore already exists, ERROR_DUPLICATE_NAME is returned.

If this field is null, the semaphore is unnamed. Unnamed mutex semaphores can be either private or shared, depending on flAttr They are identified by the semaphore handle that phmtx points to.

By default, named semaphores are shared.

phmtx (PHMTX) - output

A pointer to the handle of the mutex semaphore.

flAttr (ULONG) - input

A set of flags that specify the attributes of the semaphore.

If the DC_SEM_SHARED bit is set, the semaphore is shared. Otherwise, this flag should be set to 0L. This bit is checked only if the semaphore is unnamed (that is, if pszName is null), because all named semaphores are shared.

fState (BOOL32) - input

Initial state of the semaphore.

Possible values are shown in the following list:

• FALSE The initial state of the semaphore is "unowned."

• TRUE
  The initial state of the semaphore is "owned."

ulrc (APIRET) - returns

Return Code.

DosCreateMutexSem returns one of the following values:

• NO_ERROR 8
  ERROR_NOT_ENOUGH_MEMORY
  87
  ERROR_INVALID_PARAMETER
  123
  ERROR_INVALID_NAME
  285
  ERROR_DUPLICATE_NAME
  290
  ERROR_TOO_MANY_HANDLES
  For a full list of error codes, see Errors.