/*****************************************************************************
* events.c: events interface
* This library provides an interface to the send and receive events.
* It is more lightweight than variable based callback.
*****************************************************************************
* Copyright (C) 1998-2005 the VideoLAN team
* $Id$
*
* Authors: Pierre d'Herbemont <pdherbemont # videolan.org >
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
/*****************************************************************************
* Preamble
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "vlc_common.h"
#include <assert.h>
#include "vlc_events.h"
#include "vlc_arrays.h"
/*****************************************************************************
* Documentation : Read vlc_events.h
*****************************************************************************/
//#define DEBUG_EVENT
/*****************************************************************************
* Private types.
*****************************************************************************/
typedef struct vlc_event_listener_t
{
void * p_user_data;
vlc_event_callback_t pf_callback;
#ifdef DEBUG_EVENT
char * psz_debug_name;
#endif
} vlc_event_listener_t;
typedef struct vlc_event_listeners_group_t
{
vlc_event_type_t event_type;
DECL_ARRAY(struct vlc_event_listener_t *) listeners;
/* Used in vlc_event_send() to make sure to behave
Correctly when vlc_event_detach was called during
a callback */
bool b_sublistener_removed;
} vlc_event_listeners_group_t;
#ifdef DEBUG_EVENT
static const char ppsz_event_type_to_name[][33] =
{
[vlc_InputStateChanged] = "vlc_InputStateChanged",
[vlc_InputSelectedStreamChanged] = "vlc_InputSelectedStreamChanged",
[vlc_InputItemMetaChanged] = "vlc_InputItemMetaChanged",
[vlc_InputItemSubItemAdded] = "vlc_InputItemSubItemAdded",
[vlc_InputItemDurationChanged] = "vlc_InputItemDurationChanged",
[vlc_InputItemPreparsedChanged] = "vlc_InputItemPreparsedChanged",
[vlc_InputItemNameChanged] = "vlc_InputItemNameChanged",
[vlc_InputItemInfoChanged] = "vlc_InputItemInfoChanged",
[vlc_InputItemErrorWhenReadingChanged] = "vlc_InputItemErrorWhenReadingChanged",
[vlc_ServicesDiscoveryItemAdded] = "vlc_ServicesDiscoveryItemAdded",
[vlc_ServicesDiscoveryItemRemoved] = "vlc_ServicesDiscoveryItemRemoved"
[vlc_ServicesDiscoveryStarted] = "vlc_ServicesDiscoveryStarted"
[vlc_ServicesDiscoveryEnded] = "vlc_ServicesDiscoveryEnded"
};
#endif
static bool
listeners_are_equal( vlc_event_listener_t * listener1,
vlc_event_listener_t * listener2 )
{
return listener1->pf_callback == listener2->pf_callback &&
listener1->p_user_data == listener2->p_user_data;
}
static bool
group_contains_listener( vlc_event_listeners_group_t * group,
vlc_event_listener_t * searched_listener )
{
vlc_event_listener_t * listener;
FOREACH_ARRAY( listener, group->listeners )
if( listeners_are_equal(searched_listener, listener) )
return true;
FOREACH_END()
return false;
}
/*****************************************************************************
*
*****************************************************************************/
/**
* Initialize event manager object
* p_obj is the object that contains the event manager. But not
* necessarily a vlc_object_t (an input_item_t is not a vlc_object_t
* for instance).
* p_parent_obj gives a libvlc instance
*/
int __vlc_event_manager_init( vlc_event_manager_t * p_em, void * p_obj,
vlc_object_t * p_parent_obj )
{
p_em->p_obj = p_obj;
p_em->p_parent_object = p_parent_obj;
vlc_mutex_init( &p_em->object_lock );
/* We need a recursive lock here, because we need to be able
* to call libvlc_event_detach even if vlc_event_send is in
* the call frame.
* This ensures that after libvlc_event_detach, the callback
* will never gets triggered.
* */
vlc_mutex_init_recursive( &p_em->event_sending_lock );
ARRAY_INIT( p_em->listeners_groups );
return VLC_SUCCESS;
}
/**
* Destroy the event manager
*/
void vlc_event_manager_fini( vlc_event_manager_t * p_em )
{
struct vlc_event_listeners_group_t * listeners_group;
struct vlc_event_listener_t * listener;
vlc_mutex_destroy( &p_em->object_lock );
vlc_mutex_destroy( &p_em->event_sending_lock );
FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
FOREACH_ARRAY( listener, listeners_group->listeners )
free( listener );
FOREACH_END()
ARRAY_RESET( listeners_group->listeners );
free( listeners_group );
FOREACH_END()
ARRAY_RESET( p_em->listeners_groups );
}
/**
* Destroy the event manager
*/
int vlc_event_manager_register_event_type(
vlc_event_manager_t * p_em,
vlc_event_type_t event_type )
{
vlc_event_listeners_group_t * listeners_group;
listeners_group = malloc(sizeof(vlc_event_listeners_group_t));
if( !listeners_group )
return VLC_ENOMEM;
listeners_group->event_type = event_type;
ARRAY_INIT( listeners_group->listeners );
vlc_mutex_lock( &p_em->object_lock );
ARRAY_APPEND( p_em->listeners_groups, listeners_group );
vlc_mutex_unlock( &p_em->object_lock );
return VLC_SUCCESS;
}
/**
* Send an event to the listener attached to this p_em.
*/
void vlc_event_send( vlc_event_manager_t * p_em,
vlc_event_t * p_event )
{
vlc_event_listeners_group_t * listeners_group = NULL;
vlc_event_listener_t * listener;
vlc_event_listener_t * array_of_cached_listeners = NULL;
vlc_event_listener_t * cached_listener;
int i, i_cached_listeners = 0;
/* Fill event with the sending object now */
p_event->p_obj = p_em->p_obj;
vlc_mutex_lock( &p_em->object_lock );
FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
if( listeners_group->event_type == p_event->type )
{
if( listeners_group->listeners.i_size <= 0 )
break;
/* Save the function to call */
i_cached_listeners = listeners_group->listeners.i_size;
array_of_cached_listeners = malloc(
sizeof(vlc_event_listener_t)*i_cached_listeners );
if( !array_of_cached_listeners )
{
vlc_mutex_unlock( &p_em->object_lock );
return;
}
cached_listener = array_of_cached_listeners;
FOREACH_ARRAY( listener, listeners_group->listeners )
memcpy( cached_listener, listener, sizeof(vlc_event_listener_t));
#ifdef DEBUG_EVENT
cached_listener->psz_debug_name = strdup(cached_listener->psz_debug_name);
#endif
cached_listener++;
FOREACH_END()
break;
}
FOREACH_END()
vlc_mutex_unlock( &p_em->object_lock );
/* Call the function attached */
cached_listener = array_of_cached_listeners;
if( !listeners_group || !array_of_cached_listeners )
{
free( array_of_cached_listeners );
return;
}
vlc_mutex_lock( &p_em->event_sending_lock ) ;
/* Track item removed from *this* thread, with a simple flag */
listeners_group->b_sublistener_removed = false;
for( i = 0; i < i_cached_listeners; i++ )
{
#ifdef DEBUG_EVENT
msg_Dbg( p_em->p_parent_object,
"Calling '%s' with a '%s' event (data %p)",
cached_listener->psz_debug_name,
ppsz_event_type_to_name[p_event->type],
cached_listener->p_user_data );
free(cached_listener->psz_debug_name);
#endif
/* No need to lock on listeners_group, a listener group can't be removed */
if( listeners_group->b_sublistener_removed )
{
/* If a callback was removed, this gets called */
bool valid_listener;
vlc_mutex_lock( &p_em->object_lock );
valid_listener = group_contains_listener( listeners_group, cached_listener );
vlc_mutex_unlock( &p_em->object_lock );
if( !valid_listener )
{
#ifdef DEBUG_EVENT
msg_Dbg( p_em->p_parent_object, "Callback was removed during execution" );
#endif
cached_listener++;
continue;
}
}
cached_listener->pf_callback( p_event, cached_listener->p_user_data );
cached_listener++;
}
vlc_mutex_unlock( &p_em->event_sending_lock );
free( array_of_cached_listeners );
}
/**
* Add a callback for an event.
*/
int __vlc_event_attach( vlc_event_manager_t * p_em,
vlc_event_type_t event_type,
vlc_event_callback_t pf_callback,
void *p_user_data,
const char * psz_debug_name )
{
vlc_event_listeners_group_t * listeners_group;
vlc_event_listener_t * listener;
listener = malloc(sizeof(vlc_event_listener_t));
if( !listener )
return VLC_ENOMEM;
listener->p_user_data = p_user_data;
listener->pf_callback = pf_callback;
#ifdef DEBUG_EVENT
listener->psz_debug_name = strdup( psz_debug_name );
#else
(void)psz_debug_name;
#endif
vlc_mutex_lock( &p_em->object_lock );
FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
if( listeners_group->event_type == event_type )
{
ARRAY_APPEND( listeners_group->listeners, listener );
#ifdef DEBUG_EVENT
msg_Dbg( p_em->p_parent_object,
"Listening to '%s' event with '%s' (data %p)",
ppsz_event_type_to_name[event_type],
listener->psz_debug_name,
listener->p_user_data );
#endif
vlc_mutex_unlock( &p_em->object_lock );
return VLC_SUCCESS;
}
FOREACH_END()
vlc_mutex_unlock( &p_em->object_lock );
msg_Err( p_em->p_parent_object, "Can't attach to an object event manager event" );
free(listener);
return VLC_EGENERIC;
}
/**
* Remove a callback for an event.
*/
int vlc_event_detach( vlc_event_manager_t *p_em,
vlc_event_type_t event_type,
vlc_event_callback_t pf_callback,
void *p_user_data )
{
vlc_event_listeners_group_t * listeners_group;
struct vlc_event_listener_t * listener;
vlc_mutex_lock( &p_em->object_lock );
vlc_mutex_lock( &p_em->event_sending_lock );
FOREACH_ARRAY( listeners_group, p_em->listeners_groups )
if( listeners_group->event_type == event_type )
{
FOREACH_ARRAY( listener, listeners_group->listeners )
if( listener->pf_callback == pf_callback &&
listener->p_user_data == p_user_data )
{
/* Tell vlc_event_send, we did remove an item from that group,
in case vlc_event_send is in our caller stack */
listeners_group->b_sublistener_removed = true;
/* that's our listener */
ARRAY_REMOVE( listeners_group->listeners,
fe_idx /* This comes from the macro (and that's why
I hate macro) */ );
#ifdef DEBUG_EVENT
msg_Dbg( p_em->p_parent_object,
"Detaching '%s' from '%s' event (data %p)",
listener->psz_debug_name,
ppsz_event_type_to_name[event_type],
listener->p_user_data );
free( listener->psz_debug_name );
#endif
free( listener );
vlc_mutex_unlock( &p_em->event_sending_lock );
vlc_mutex_unlock( &p_em->object_lock );
return VLC_SUCCESS;
}
FOREACH_END()
}
FOREACH_END()
vlc_mutex_unlock( &p_em->event_sending_lock );
vlc_mutex_unlock( &p_em->object_lock );
msg_Warn( p_em->p_parent_object, "Can't detach to an object event manager event" );
return VLC_EGENERIC;
}
