CTA event structure

NMS OAM events arrive encapsulated in the standard CTA_EVENT data structure (defined in ctadef.h):

typedef struct CTA_EVENT
{
    DWORD    id;             /* Event code (and source service id)      */
    CTAHD    ctahd;          /* Context handle                          */
    DWORD    timestamp;      /* Timestamp                               */
    DWORD    userid;         /* User id (defined by ctaCreateContext)   */
    DWORD    size;           /* Size of buffer if buffer != NULL        */
    void     *buffer;        /* Buffer pointer                          */
    DWORD    value;          /* Event status or event-specific data     */
    DWORD    objHd;          /* Service client side object handle       */
} CTA_EVENT;

This structure, returned by ctaWaitEvent, informs the application which event occurred on which context, and includes additional information specific to the event.

The CTA_EVENT structure contains the following fields:

Field	Description
id	Event code defined in the library header file. For example: OAMEVN_SOMETHING_ HAPPENED. For a list of NMS OAM event codes, see NMS OAM events.
ctahd	Context handle returned from ctaCreateContext.
timestamp	Time when the event was created in milliseconds since midnight, January 1, 1970, modulo 49 days. An application can decode the timestamp using ctaGetTimeStamp.
userid	User-supplied identifier. This field is unaltered by Natural Access and facilitates asynchronous programming. Its purpose is to correlate a context with an application object/context when events occur.
size	Size (bytes) of the area to which the buffer field points. This field also indicates whether a data buffer associated with the event must be freed using ctaFreeBuffer. If the buffer is NULL, this field can hold an event-specific value. For NMS OAM events, size indicates the size of the OAM_MSG structure.
buffer	Pointer to data returned with the event. The field contains an application process address and the event's size field contains the actual size of the buffer. For NMS OAM events, the buffer points to an OAM_MSG structure. Note: After processing an NMS OAM event, the application must free the event buffer for Natural Access. For more information, see Event buffer management.
value	Event-specific value. If the event is a DONE event (an event indicating that a function was successfully invoked, such as OAMEVN_STARTBOARD_DONE), this field holds a reason code indicating the actual results of the function. For more information, see NMS OAM reason codes.
objHd	The service client-side object handle.