LDI_ADD_EVENT_HANDLER(9F) Kernel Functions for Drivers


ldi_add_event_handler - add NDI event service callback handler


#include <sys/ddi_obsolete.h>

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);




ldi_handle_t lh

Layered handle representing event notification device.

ddi_eventcookie_t ec

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.

void *arg

Pointer to opaque data supplied by caller. Typically, this is a
pointer to the layered driver's softstate structure.

ldi_callback_id_t *id

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.


This function is obsolete and is only maintained for compatibility. Use
of this function is strongly discouraged. For equivalent functionality
provided by new interfaces, see ldi_ev_get_cookie(9F) and

The ldi_add_event_handler() function adds a callback handler to be
invoked at the occurrence 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.


Callback handler registered successfully.

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.


ldi_ev_get_cookie(9F), ldi_ev_register_callbacks(9F),
ldi_get_eventcookie(9F), ldi_remove_event_handler(9F)

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.

illumos April 9, 2016 LDI_ADD_EVENT_HANDLER(9F)