int ldi_add_event_handler(ldi_handle_t lh, ddi_eventcookie_t ec, void (*handler)(ldi_handle_t, ddi_eventcookie_t, void *, void *) void *arg, ldi_callback_id_t *id);
Solaris DDI Specific (Solaris DDI).
Layered handle representing event notification device.
Cookie returned from call to ldi_get_eventcookie(9F).
void (*handler)(ldi_handle_t, ddi_eventcookie_t, void *, void *)
Callback handler for NDI event service notification.
Pointer to opaque data supplied by caller. Typically, this is a pointer to the layered driver's softstate structure.
Pointer to registration id, where a unique registration id is returned. Registration id must be saved and used when calling ldi_remove_event_handler(9F) to unregister a callback handler.
The ldi_add_event_handler() function adds a callback handler to be invoked at the occurance of the event specified by the cookie. Adding a callback handler is also known as subscribing to an event. Upon successful subscription, the handler is invoked when the event occurs. You can unregister the handler by using ldi_remove_event_handler(9F).
An instance of a layered driver can register multiple handlers for an event or a single handler for multiple events. Callback order is not defined and should be assumed to be random.
The routine handler is invoked with the following arguments:
ldi_handle_t lh Layered handle representing the device for which the event notification is requested.
ddi_eventcookie_t ec Structure describing event that occurred.
void *arg Opaque data pointer provided by the driver during callback registration.
void *impl_data Pointer to event specific data defined by the framework that invokes the callback function.
DDI_SUCCESS Callback handler registered successfully.
DDI_FAILURE Failed to register callback handler. Possible reasons include lack of resources or a bad cookie.
The ldi_add_event_handler() function can be called from user and kernel contexts only.
Writing Device Drivers
Layered drivers must remove all registered callback handlers for a device instance, represented by the layered handle, by calling ldi_remove_event_handler(9F) before the layered driver's detach(9E) routine completes.