DBusPendingCall
[D-Bus low-level public API]

Pending reply to a method call message. More...


Typedefs
typedef DBusPendingCall	DBusPendingCall
	Opaque type representing a method call that has not yet received a reply.
Functions
DBusPendingCall *	dbus_pending_call_ref (DBusPendingCall *pending)
	Increments the reference count on a pending call.
void	dbus_pending_call_unref (DBusPendingCall *pending)
	Decrements the reference count on a pending call, freeing it if the count reaches 0.
dbus_bool_t	dbus_pending_call_set_notify (DBusPendingCall pending, DBusPendingCallNotifyFunction function, void user_data, DBusFreeFunction free_user_data)
	Sets a notification function to be called when the reply is received or the pending call times out.
void	dbus_pending_call_cancel (DBusPendingCall *pending)
	Cancels the pending call, such that any reply or error received will just be ignored.
dbus_bool_t	dbus_pending_call_get_completed (DBusPendingCall *pending)
	Checks whether the pending call has received a reply yet, or not.
DBusMessage *	dbus_pending_call_steal_reply (DBusPendingCall *pending)
	Gets the reply, or returns NULL if none has been received yet.
void	dbus_pending_call_block (DBusPendingCall *pending)
	Block until the pending call is completed.
dbus_bool_t	dbus_pending_call_allocate_data_slot (dbus_int32_t *slot_p)
	Allocates an integer ID to be used for storing application-specific data on any DBusPendingCall.
void	dbus_pending_call_free_data_slot (dbus_int32_t *slot_p)
	Deallocates a global ID for DBusPendingCall data slots.
dbus_bool_t	dbus_pending_call_set_data (DBusPendingCall pending, dbus_int32_t slot, void data, DBusFreeFunction free_data_func)
	Stores a pointer on a DBusPendingCall, along with an optional function to be used for freeing the data when the data is set again, or when the pending call is finalized.
void *	dbus_pending_call_get_data (DBusPendingCall *pending, dbus_int32_t slot)
	Retrieves data previously set with dbus_pending_call_set_data().

Detailed Description

Pending reply to a method call message.

A DBusPendingCall is an object representing an expected reply. A DBusPendingCall can be created when you send a message that should have a reply.

Function Documentation

dbus_bool_t dbus_pending_call_allocate_data_slot ( dbus_int32_t * slot_p )

Allocates an integer ID to be used for storing application-specific data on any DBusPendingCall.

The allocated ID may then be used with dbus_pending_call_set_data() and dbus_pending_call_get_data(). The passed-in slot must be initialized to -1, and is filled in with the slot ID. If the passed-in slot is not -1, it's assumed to be already allocated, and its refcount is incremented.

The allocated slot is global, i.e. all DBusPendingCall objects will have a slot with the given integer ID reserved.

Parameters:

slot_p

address of a global variable storing the slot

Returns:: FALSE on failure (no memory)

Definition at line 725 of file dbus-pending-call.c.

References _dbus_data_slot_allocator_alloc(), _DBUS_LOCK_NAME, FALSE, and NULL.

Referenced by _dbus_pending_call_new_unlocked().

void dbus_pending_call_block ( DBusPendingCall * pending )

Block until the pending call is completed.

The blocking is as with dbus_connection_send_with_reply_and_block(); it does not enter the main loop or process other messages, it simply waits for the reply in question.

If the pending call is already completed, this function returns immediately.

Todo:: when you start blocking, the timeout is reset, but it should really only use time remaining since the pending call was created. This requires storing timestamps instead of intervals in the timeout

Parameters:

pending

the pending call

Definition at line 703 of file dbus-pending-call.c.

References _dbus_connection_block_pending_call(), and NULL.

Referenced by dbus_connection_send_with_reply_and_block().

void dbus_pending_call_cancel ( DBusPendingCall * pending )

Cancels the pending call, such that any reply or error received will just be ignored.

Drops the dbus library's internal reference to the DBusPendingCall so will free the call if nobody else is holding a reference. However you usually get a reference from dbus_connection_send_with_reply() so probably your app owns a ref also.

Note that canceling a pending call will not simulate a timed-out call; if a call times out, then a timeout error reply is received. If you cancel the call, no reply is received unless the the reply was already received before you canceled.

Parameters:

pending

the pending call

Definition at line 630 of file dbus-pending-call.c.

References _dbus_connection_remove_pending_call(), connection, and NULL.

void dbus_pending_call_free_data_slot ( dbus_int32_t * slot_p )

Deallocates a global ID for DBusPendingCall data slots.

dbus_pending_call_get_data() and dbus_pending_call_set_data() may no longer be used with this slot. Existing data stored on existing DBusPendingCall objects will be freed when the DBusPendingCall is finalized, but may not be retrieved (and may only be replaced if someone else reallocates the slot). When the refcount on the passed-in slot reaches 0, it is set to -1.

Parameters:

slot_p

address storing the slot to deallocate

Definition at line 746 of file dbus-pending-call.c.

References _dbus_data_slot_allocator_free(), and NULL.

Referenced by _dbus_pending_call_new_unlocked().

dbus_bool_t dbus_pending_call_get_completed ( DBusPendingCall * pending )

Checks whether the pending call has received a reply yet, or not.

Parameters:

pending

the pending call

Returns:: TRUE if a reply has been received

Definition at line 646 of file dbus-pending-call.c.

References completed, connection, CONNECTION_LOCK, CONNECTION_UNLOCK, FALSE, and NULL.

Referenced by _dbus_connection_block_pending_call().

void * dbus_pending_call_get_data	(	DBusPendingCall *	pending,
		dbus_int32_t	slot
	)

Retrieves data previously set with dbus_pending_call_set_data().

The slot must still be allocated (must not have been freed).

Parameters:

	pending	the pending_call
	slot	the slot to get data from

Returns:: the data, or NULL if not found

Definition at line 794 of file dbus-pending-call.c.

References _dbus_data_slot_list_get(), connection, CONNECTION_LOCK, CONNECTION_UNLOCK, NULL, and slot_list.

Referenced by _dbus_pending_call_complete().

DBusPendingCall * dbus_pending_call_ref ( DBusPendingCall * pending )

Increments the reference count on a pending call.

Parameters:

pending

the pending call object

Returns:: the pending call object

Definition at line 532 of file dbus-pending-call.c.

References _dbus_assert, _dbus_atomic_inc(), connection, CONNECTION_LOCK, CONNECTION_UNLOCK, NULL, refcount, and DBusAtomic::value.

Referenced by _dbus_connection_block_pending_call().

dbus_bool_t dbus_pending_call_set_data	(	DBusPendingCall *	pending,
		dbus_int32_t	slot,
		void *	data,
		DBusFreeFunction	free_data_func
	)

Stores a pointer on a DBusPendingCall, along with an optional function to be used for freeing the data when the data is set again, or when the pending call is finalized.

The slot number must have been allocated with dbus_pending_call_allocate_data_slot().

Parameters:

	pending	the pending_call
	slot	the slot number
	data	the data to store
	free_data_func	finalizer function for the data

Returns:: TRUE if there was enough memory to store the data

Definition at line 768 of file dbus-pending-call.c.

References _dbus_pending_call_set_data_unlocked(), connection, CONNECTION_LOCK, CONNECTION_UNLOCK, FALSE, and NULL.

dbus_bool_t dbus_pending_call_set_notify	(	DBusPendingCall *	pending,
		DBusPendingCallNotifyFunction	function,
		void *	user_data,
		DBusFreeFunction	free_user_data
	)

Sets a notification function to be called when the reply is received or the pending call times out.

Parameters:

	pending	the pending call
	function	notifier function
	user_data	data to pass to notifier function
	free_user_data	function to free the user data

Returns:: FALSE if not enough memory

Definition at line 593 of file dbus-pending-call.c.

References _dbus_pending_call_set_data_unlocked(), connection, CONNECTION_LOCK, CONNECTION_UNLOCK, FALSE, NULL, and TRUE.

DBusMessage * dbus_pending_call_steal_reply ( DBusPendingCall * pending )

Gets the reply, or returns NULL if none has been received yet.

Ownership of the reply message passes to the caller. This function can only be called once per pending call, since the reply message is tranferred to the caller.

Parameters:

pending

the pending call