Tracking state changes

When the WiMAX devices change state, the kernel sends state change notification. More...

Typedefs
typedef int(*	wimaxll_state_change_cb_f )(struct wimaxll_handle *, void *priv, enum wimax_st old_state, enum wimax_st new_state)
	Callback for a state change notification from the WiMAX kernel stack. More...

Functions
void	wimaxll_get_cb_state_change (struct wimaxll_handle *wmx, wimaxll_state_change_cb_f *cb, void **priv)
	Get the callback and priv pointer for a WIMAX_GNL_RE_STATE_CHANGE message. More...
void	wimaxll_set_cb_state_change (struct wimaxll_handle *wmx, wimaxll_state_change_cb_f cb, void *priv)
	Set the callback and priv pointer for a WIMAX_GNL_RE_STATE_CHANGE message. More...
ssize_t	wimaxll_wait_for_state_change (struct wimaxll_handle *wmx, enum wimax_st *old_state, enum wimax_st *new_state)
	Wait for an state change notification from the kernel. More...

Detailed Description

When the WiMAX devices change state, the kernel sends state change notification.

An application can simply block a thread waiting for state changes using the following convenience function:

* result = wimaxll_wait_for_state_change(wmx, &old_state, &new_state);
* 

However, in most cases, applications will want to integrate into main loops and use the callback mechanism.

For that, they just need to set a callback for the state change notification:

* wimaxll_set_cb_state_change(wmx, my_state_change_callback, context_pointer);
* 

and then wait for notifications to be available (see receiving with select()). When data is available and wimax_recv() is called to process it, the callback will be executed for each state change notification.

Applications can query the current callback set for the state change notifications with wimaxll_get_cb_state_change().

Typedef Documentation

typedef int(* wimaxll_state_change_cb_f)(struct wimaxll_handle *, void *priv, enum wimax_st old_state, enum wimax_st new_state)

Callback for a state change notification from the WiMAX kernel stack.

The WiMAX device has changed state from old_state to new_state.

Note

See Callbacks callbacks for a set of warnings and guidelines for using callbacks.

Parameters

wmx	WiMAX device handle
priv	ctx Context passed by the user with wimaxll_set_cb_state_change().
old_state	State the WiMAX device left
new_state	State the WiMAX device entered

Returns

>= 0 if it is ok to keep processing messages, -EBUSY if message processing should stop and control be returned to the caller. Any other negative error code to continue processing messages skipping the current one.

Function Documentation

void wimaxll_get_cb_state_change	(	struct wimaxll_handle *	wmx,
		wimaxll_state_change_cb_f *	cb,
		void **	priv
	)

Get the callback and priv pointer for a WIMAX_GNL_RE_STATE_CHANGE message.

Parameters

wmx	WiMAX handle.
cb	Where to store the current callback function.
priv	Where to store the private data pointer passed to the callback.

Referenced by wimaxll_wait_for_state_change().

void wimaxll_set_cb_state_change	(	struct wimaxll_handle *	wmx,
		wimaxll_state_change_cb_f	cb,
		void *	priv
	)

Set the callback and priv pointer for a WIMAX_GNL_RE_STATE_CHANGE message.

Parameters

wmx	WiMAX handle.
cb	Callback function to set
priv	Private data pointer to pass to the callback function.

Referenced by wimaxll_wait_for_state_change().

ssize_t wimaxll_wait_for_state_change	(	struct wimaxll_handle *	wmx,
		enum wimax_st *	old_state,
		enum wimax_st *	new_state
	)

Wait for an state change notification from the kernel.

Parameters

wmx	WiMAX device handle
old_state	Pointer to where to store the previous state
new_state	Pointer to where to store the new state

Returns

If successful, 0 and the values pointed to by the old_state and new_state arguments are valid; on error, a negative errno code and the state pointers contain no valid information.

Waits for the WiMAX device to change state and reports said state change.

Internally, this function uses wimax_recv() , which means that on reception (from the kernel) of notifications other than state change, any callbacks that are set for them will be executed.

Note

This is a blocking call.

This function cannot be run in parallel with other code that modifies the state change callbacks for this same handle.