MP_RegisterForObjectPropertyChanges

- register a client function to be called

Synopsis

cc [ flag… ] file… -lMPAPI [ library… ]
#include <mpapi.h>

MP_STATUS MP_RegisterForObjectPropertyChanges(
     MP_OBJECT_PROPERTY_FN pClientFn, MP_OBJECT_TYPE objectType,
     void *pCallerData, MP_OID pluginOid);

Parameters

pClientFn

A pointer to an object ID that has type MP_OBJECT_PROPERTY_FN function defined by the client. With a successful return, this function is called to inform the client of objects that have had one or more properties changed.

objectType

The type of object the client wishes to register for property change callbacks.

pCallerData

A pointer that is passed to the callback routine with each event. This might be used by the caller to correlate the event to the source of the registration.

pluginOid

If this is a valid plugin object ID, then registration is limited to that plugin. If this is zero, then the registration is for all plugins.

Description

The MP_RegisterForObjectPropertyChanges() function registers a client function to be called whenever the property of an object changes.

The function specified by pClientFn is called whenever the property of an object changes. For the purposes of this function, a property is defined to be a field in an object's property structure and the object's status. Therefore, the client function is not called if a statistic of the associated object changes. But, it is called when the status changes (e.g., from working to failed) or when a name or other field in a property structure changes.

It is not an error to re-register a client function. However, a client function has only one registration. The first call to deregister a client function will deregister it no matter how many calls to register the function have been made.

If multiple properties of an object change simultaneously, a client function can be called only once to be notified that all the changes have occurred.

Return Values

MP_STATUS_INVALID_OBJECT_TYPE

The pluginOid or objectType does not specify any valid object type. This is most likely to happen if an uninitialized object ID is passed to the API.

MP_STATUS_OBJECT_NOT_FOUND

The pluginOid owner ID or object sequence number is invalid.

MP_STATUS_INVALID_PARAMETER

The pCallerData is null or if the pluginOid has a type subfield other than MP_OBJECT_TYPE_PLUGIN, or when objectType is invalid.

MP_STATUS_SUCCESS

The operation is successful.

MP_STATUS_FN_REPLACED

An existing client function is replaced with the one specified in pClientFn.

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

libMPAPI(3LIB), MP_DeregisterForObjectPropertyChanges(3MPAPI), attributes(5)

Multipath Management API Version 1.0