From 7da966334cdcc989b548edcde51ab809a4ba37d1 Mon Sep 17 00:00:00 2001 From: Pierre d'Herbemont Date: Tue, 2 Jun 2009 00:24:42 -0700 Subject: [PATCH] libvlc: Allow event to be dispatched asynchronously. --- src/Makefile.am | 2 + src/control/event.c | 146 ++++++++++++++------- src/control/event_async.c | 237 ++++++++++++++++++++++++++++++++++ src/control/event_internal.h | 113 ++++++++++++++++ src/control/libvlc_internal.h | 68 +--------- 5 files changed, 459 insertions(+), 107 deletions(-) create mode 100644 src/control/event_async.c create mode 100644 src/control/event_internal.h diff --git a/src/Makefile.am b/src/Makefile.am index a59820684b..84f380aec2 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -439,6 +439,7 @@ SOURCES_libvlc = \ SOURCES_libvlc_control = \ control/libvlc_internal.h \ + control/event_internal.h \ control/media_internal.h \ control/media_list_internal.h \ control/media_list_view_internal.h \ @@ -450,6 +451,7 @@ SOURCES_libvlc_control = \ control/video.c \ control/audio.c \ control/event.c \ + control/event_async.c \ control/flat_media_list_view.c \ control/hierarchical_media_list_view.c \ control/hierarchical_node_media_list_view.c \ diff --git a/src/control/event.c b/src/control/event.c index ae35e300b4..235c27dda2 100644 --- a/src/control/event.c +++ b/src/control/event.c @@ -22,23 +22,22 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. *****************************************************************************/ -#include "libvlc_internal.h" #include -#include + +#include "libvlc_internal.h" +#include "event_internal.h" + +typedef struct libvlc_event_listeners_group_t +{ + libvlc_event_type_t event_type; + vlc_array_t listeners; + bool b_sublistener_removed; +} libvlc_event_listeners_group_t; /* * Private functions */ -static bool -listeners_are_equal( libvlc_event_listener_t * listener1, - libvlc_event_listener_t * listener2 ) -{ - return listener1->event_type == listener2->event_type && - listener1->pf_callback == listener2->pf_callback && - listener1->p_user_data == listener2->p_user_data; -} - static bool group_contains_listener( libvlc_event_listeners_group_t * group, libvlc_event_listener_t * searched_listener ) @@ -75,7 +74,10 @@ libvlc_event_manager_new( void * p_obj, libvlc_instance_t * p_libvlc_inst, } p_em->p_obj = p_obj; + p_em->p_obj = p_obj; + p_em->async_event_queue = NULL; p_em->p_libvlc_instance = p_libvlc_inst; + libvlc_retain( p_libvlc_inst ); vlc_array_init( &p_em->listeners_groups ); vlc_mutex_init( &p_em->object_lock ); @@ -93,6 +95,8 @@ void libvlc_event_manager_release( libvlc_event_manager_t * p_em ) libvlc_event_listeners_group_t * p_lg; int i,j ; + libvlc_event_async_fini(p_em); + vlc_mutex_destroy( &p_em->event_sending_lock ); vlc_mutex_destroy( &p_em->object_lock ); @@ -165,7 +169,8 @@ void libvlc_event_send( libvlc_event_manager_t * p_em, if( vlc_array_count( &listeners_group->listeners ) <= 0 ) break; - /* Cache a copy of the listener to avoid locking issues */ + /* Cache a copy of the listener to avoid locking issues, + * and allow that edition of listeners during callbacks will garantee immediate effect. */ i_cached_listeners = vlc_array_count(&listeners_group->listeners); array_listeners_cached = malloc(sizeof(libvlc_event_listener_t)*(i_cached_listeners)); if( !array_listeners_cached ) @@ -200,22 +205,32 @@ void libvlc_event_send( libvlc_event_manager_t * p_em, listeners_group->b_sublistener_removed = false; for( i = 0; i < i_cached_listeners; i++ ) { - if( listeners_group->b_sublistener_removed ) + if(listener_cached->is_asynchronous) { - /* 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, listener_cached ); - vlc_mutex_unlock( &p_em->object_lock ); - if( !valid_listener ) + /* The listener wants not to block the emitter during event callback */ + libvlc_event_async_dispatch(p_em, listener_cached, p_event); + } + else + { + /* The listener wants to block the emitter during event callback */ + + listener_cached->pf_callback( p_event, listener_cached->p_user_data ); + listener_cached++; + + if( listeners_group->b_sublistener_removed ) { - listener_cached++; - continue; - } + /* 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, listener_cached ); + vlc_mutex_unlock( &p_em->object_lock ); + if( !valid_listener ) + { + listener_cached++; + continue; + } + } } - - listener_cached->pf_callback( p_event, listener_cached->p_user_data ); - listener_cached++; } vlc_mutex_unlock( &p_em->event_sending_lock ); @@ -287,31 +302,34 @@ const char * libvlc_event_type_name( libvlc_event_type_t event_type ) } /************************************************************************** - * libvlc_event_attach (public) : + * event_attach (internal) : * * Add a callback for an event. **************************************************************************/ -void libvlc_event_attach( libvlc_event_manager_t * p_event_manager, - libvlc_event_type_t event_type, - libvlc_callback_t pf_callback, - void *p_user_data, - libvlc_exception_t *p_e ) +static +void event_attach( libvlc_event_manager_t * p_event_manager, + libvlc_event_type_t event_type, + libvlc_callback_t pf_callback, + void *p_user_data, + bool is_asynchronous, + libvlc_exception_t *p_e ) { libvlc_event_listeners_group_t * listeners_group; libvlc_event_listener_t * listener; int i; - + listener = malloc(sizeof(libvlc_event_listener_t)); if( !listener ) { libvlc_exception_raise( p_e, "No Memory left" ); return; } - + listener->event_type = event_type; listener->p_user_data = p_user_data; listener->pf_callback = pf_callback; - + listener->is_asynchronous = is_asynchronous; + vlc_mutex_lock( &p_event_manager->object_lock ); for( i = 0; i < vlc_array_count(&p_event_manager->listeners_groups); i++ ) { @@ -324,11 +342,39 @@ void libvlc_event_attach( libvlc_event_manager_t * p_event_manager, } } vlc_mutex_unlock( &p_event_manager->object_lock ); - + free(listener); libvlc_exception_raise( p_e, - "This object event manager doesn't know about '%s' events", - libvlc_event_type_name(event_type)); + "This object event manager doesn't know about '%s' events", + libvlc_event_type_name(event_type)); +} + +/************************************************************************** + * libvlc_event_attach (public) : + * + * Add a callback for an event. + **************************************************************************/ +void libvlc_event_attach( libvlc_event_manager_t * p_event_manager, + libvlc_event_type_t event_type, + libvlc_callback_t pf_callback, + void *p_user_data, + libvlc_exception_t *p_e ) +{ + event_attach(p_event_manager, event_type, pf_callback, p_user_data, false /* synchronous */, p_e); +} + +/************************************************************************** + * libvlc_event_attach (public) : + * + * Add a callback for an event. + **************************************************************************/ +void libvlc_event_attach_async( libvlc_event_manager_t * p_event_manager, + libvlc_event_type_t event_type, + libvlc_callback_t pf_callback, + void *p_user_data, + libvlc_exception_t *p_e ) +{ + event_attach(p_event_manager, event_type, pf_callback, p_user_data, true /* asynchronous */, p_e); } /************************************************************************** @@ -345,7 +391,8 @@ void libvlc_event_detach( libvlc_event_manager_t *p_event_manager, libvlc_event_listeners_group_t * listeners_group; libvlc_event_listener_t * listener; int i, j; - + bool found = false; + vlc_mutex_lock( &p_event_manager->event_sending_lock ); vlc_mutex_lock( &p_event_manager->object_lock ); for( i = 0; i < vlc_array_count(&p_event_manager->listeners_groups); i++) @@ -368,9 +415,8 @@ void libvlc_event_detach( libvlc_event_manager_t *p_event_manager, free( listener ); vlc_array_remove( &listeners_group->listeners, j ); - vlc_mutex_unlock( &p_event_manager->object_lock ); - vlc_mutex_unlock( &p_event_manager->event_sending_lock ); - return; + found = true; + break; } } } @@ -378,7 +424,19 @@ void libvlc_event_detach( libvlc_event_manager_t *p_event_manager, vlc_mutex_unlock( &p_event_manager->object_lock ); vlc_mutex_unlock( &p_event_manager->event_sending_lock ); - libvlc_exception_raise( p_e, - "This object event manager doesn't know about '%s,%p,%p' event observer", - libvlc_event_type_name(event_type), pf_callback, p_user_data ); + /* Now make sure any pending async event won't get fired after that point */ + libvlc_event_listener_t listener_to_remove; + listener_to_remove.event_type = event_type; + listener_to_remove.pf_callback = pf_callback; + listener_to_remove.p_user_data = p_user_data; + listener_to_remove.is_asynchronous = true; + + libvlc_event_async_ensure_listener_removal(p_event_manager, &listener_to_remove); + + if(!found) + { + libvlc_exception_raise( p_e, + "This object event manager doesn't know about '%s,%p,%p' event observer", + libvlc_event_type_name(event_type), pf_callback, p_user_data ); + } } diff --git a/src/control/event_async.c b/src/control/event_async.c new file mode 100644 index 0000000000..ef6d6756be --- /dev/null +++ b/src/control/event_async.c @@ -0,0 +1,237 @@ +/***************************************************************************** + * event.c: New libvlc event control API + ***************************************************************************** + * Copyright (C) 2007 the VideoLAN team + * $Id $ + * + * Authors: Filippo Carone + * Pierre d'Herbemont + * + * 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. + *****************************************************************************/ + +#include + +#include "libvlc_internal.h" +#include "event_internal.h" + +struct queue_elmt { + libvlc_event_listener_t listener; + libvlc_event_t event; + struct queue_elmt * next; +}; + +struct libvlc_event_async_queue { + struct queue_elmt * elements; + vlc_mutex_t lock; + vlc_cond_t signal; + vlc_thread_t thread; +}; + +/* + * Utilities + */ + +static void* event_async_loop(void * arg); + +static inline struct libvlc_event_async_queue * queue(libvlc_event_manager_t * p_em) +{ + return p_em->async_event_queue; +} + +static inline bool is_queue_initialized(libvlc_event_manager_t * p_em) +{ + return queue(p_em) != NULL; +} + +/* Lock must be held */ +static void push(libvlc_event_manager_t * p_em, libvlc_event_listener_t * listener, libvlc_event_t * event) +{ +#ifndef NDEBUG + static const long MaxQueuedItem = 300000; + long count = 0; +#endif + + struct queue_elmt * elmt = malloc(sizeof(struct queue_elmt)); + elmt->listener = *listener; + elmt->event = *event; + elmt->next = NULL; + + /* Append to the end of the queue */ + struct queue_elmt * iter = queue(p_em)->elements; + if(!iter) + { + queue(p_em)->elements = elmt; + return; + } + + while (iter->next) { + iter = iter->next; +#ifndef NDEBUG + if(count++ > MaxQueuedItem) + { + fprintf(stderr, "Warning: libvlc event overflow.\n"); + abort(); + } +#endif + } + iter->next = elmt; +} + +/* Lock must be held */ +static bool pop(libvlc_event_manager_t * p_em, libvlc_event_listener_t * listener, libvlc_event_t * event) +{ + if(!queue(p_em)->elements) + return false; /* No elements */ + + *listener = queue(p_em)->elements->listener; + *event = queue(p_em)->elements->event; + + struct queue_elmt * elmt = queue(p_em)->elements; + queue(p_em)->elements = elmt->next; + free(elmt); + return true; +} + +/* Lock must be held */ +static void pop_listener(libvlc_event_manager_t * p_em, libvlc_event_listener_t * listener) +{ + struct queue_elmt * iter = queue(p_em)->elements; + struct queue_elmt * prev = NULL; + while (iter) { + if(listeners_are_equal(&iter->listener, listener)) + { + if(!prev) + queue(p_em)->elements = iter->next; + else + prev->next = iter->next; + free(iter); + } + prev = iter; + iter = iter->next; + } +} + +/************************************************************************** + * libvlc_event_async_fini (internal) : + * + * Destroy what might have been created by. + **************************************************************************/ +void +libvlc_event_async_fini(libvlc_event_manager_t * p_em) +{ + if(!is_queue_initialized(p_em)) return; + + vlc_thread_t thread = queue(p_em)->thread; + if(thread) + { + vlc_cancel(thread); + vlc_join(thread, NULL); + } + + vlc_mutex_destroy(&queue(p_em)->lock); + vlc_cond_destroy(&queue(p_em)->signal); + + struct queue_elmt * iter = queue(p_em)->elements; + while (iter) { + struct queue_elmt * elemt_to_delete = iter; + iter = iter->next; + free(elemt_to_delete); + } + + free(queue(p_em)); +} + +/************************************************************************** + * libvlc_event_async_init (private) : + * + * Destroy what might have been created by. + **************************************************************************/ +static void +libvlc_event_async_init(libvlc_event_manager_t * p_em) +{ + p_em->async_event_queue = calloc(1, sizeof(struct libvlc_event_async_queue)); + + int error = vlc_clone (&queue(p_em)->thread, event_async_loop, p_em, VLC_THREAD_PRIORITY_LOW); + if(error) + { + free(p_em->async_event_queue); + p_em->async_event_queue = NULL; + return; + } + + vlc_mutex_init_recursive(&queue(p_em)->lock); // Beware, this is re-entrant + vlc_cond_init(&queue(p_em)->signal); +} + +/************************************************************************** + * libvlc_event_async_ensure_listener_removal (internal) : + * + * Make sure no more message will be issued to the listener. + **************************************************************************/ +void +libvlc_event_async_ensure_listener_removal(libvlc_event_manager_t * p_em, libvlc_event_listener_t * listener) +{ + if(!is_queue_initialized(p_em)) return; + + vlc_mutex_lock(&queue(p_em)->lock); + pop_listener(p_em, listener); + vlc_mutex_unlock(&queue(p_em)->lock); +} + +/************************************************************************** + * libvlc_event_async_dispatch (internal) : + * + * Send an event in an asynchronous way. + **************************************************************************/ +void +libvlc_event_async_dispatch(libvlc_event_manager_t * p_em, libvlc_event_listener_t * listener, libvlc_event_t * event) +{ + // We do a lazy init here, to prevent constructing the thread when not needed. + vlc_mutex_lock(&p_em->object_lock); + if(!queue(p_em)) + libvlc_event_async_init(p_em); + vlc_mutex_unlock(&p_em->object_lock); + + vlc_mutex_lock(&queue(p_em)->lock); + push(p_em, listener, event); + vlc_cond_signal(&queue(p_em)->signal); + vlc_mutex_unlock(&queue(p_em)->lock); +} + +/************************************************************************** + * event_async_loop (private) : + * + * Send queued events. + **************************************************************************/ +static void * event_async_loop(void * arg) +{ + libvlc_event_manager_t * p_em = arg; + libvlc_event_listener_t listener; + libvlc_event_t event; + + vlc_mutex_lock(&queue(p_em)->lock); + vlc_cleanup_push(vlc_cleanup_lock, &queue(p_em)->lock); + while (true) { + int has_listener = pop(p_em, &listener, &event); + if (has_listener) + listener.pf_callback( &event, listener.p_user_data ); // This might edit the queue, ->lock is recursive + else + vlc_cond_wait(&queue(p_em)->signal, &queue(p_em)->lock); + } + vlc_cleanup_pop(); + vlc_mutex_unlock(&queue(p_em)->lock); + return NULL; +} diff --git a/src/control/event_internal.h b/src/control/event_internal.h new file mode 100644 index 0000000000..b7df2cbfbf --- /dev/null +++ b/src/control/event_internal.h @@ -0,0 +1,113 @@ +/***************************************************************************** + * libvlc_internal.h : Definition of opaque structures for libvlc exported API + * Also contains some internal utility functions + ***************************************************************************** + * Copyright (C) 2005-2009 the VideoLAN team + * $Id$ + * + * Authors: Clément Stenac + * + * 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. + *****************************************************************************/ + +#ifndef _LIBVLC_EVENT_H +#define _LIBVLC_EVENT_H 1 + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include +#include +#include + +#include + + +/* + * Event Handling + */ + +/* Example usage + * + * struct libvlc_cool_object_t + * { + * ... + * libvlc_event_manager_t * p_event_manager; + * ... + * } + * + * libvlc_my_cool_object_new() + * { + * ... + * p_self->p_event_manager = libvlc_event_manager_new( p_self, + * p_self->p_libvlc_instance, p_e); + * libvlc_event_manager_register_event_type(p_self->p_event_manager, + * libvlc_MyCoolObjectDidSomething, p_e) + * ... + * } + * + * libvlc_my_cool_object_release() + * { + * ... + * libvlc_event_manager_release( p_self->p_event_manager ); + * ... + * } + * + * libvlc_my_cool_object_do_something() + * { + * ... + * libvlc_event_t event; + * event.type = libvlc_MyCoolObjectDidSomething; + * event.u.my_cool_object_did_something.what_it_did = kSomething; + * libvlc_event_send( p_self->p_event_manager, &event ); + * } + * */ + +typedef struct libvlc_event_listener_t +{ + libvlc_event_type_t event_type; + void * p_user_data; + libvlc_callback_t pf_callback; + bool is_asynchronous; +} libvlc_event_listener_t; + +typedef struct libvlc_event_manager_t +{ + void * p_obj; + struct libvlc_instance_t * p_libvlc_instance; + vlc_array_t listeners_groups; + vlc_mutex_t object_lock; + vlc_mutex_t event_sending_lock; + struct libvlc_event_async_queue * async_event_queue; +} libvlc_event_sender_t; + + +static inline bool +listeners_are_equal( libvlc_event_listener_t * listener1, + libvlc_event_listener_t * listener2 ) +{ + return listener1->event_type == listener2->event_type && + listener1->pf_callback == listener2->pf_callback && + listener1->p_user_data == listener2->p_user_data && + listener1->is_asynchronous == listener2->is_asynchronous; +} + +/* event_async.c */ +void libvlc_event_async_fini(libvlc_event_manager_t * p_em); +void libvlc_event_async_dispatch(libvlc_event_manager_t * p_em, libvlc_event_listener_t * listener, libvlc_event_t * event); +void libvlc_event_async_ensure_listener_removal(libvlc_event_manager_t * p_em, libvlc_event_listener_t * listener); + +#endif diff --git a/src/control/libvlc_internal.h b/src/control/libvlc_internal.h index e37e3db8c8..2d62b1b079 100644 --- a/src/control/libvlc_internal.h +++ b/src/control/libvlc_internal.h @@ -71,69 +71,6 @@ struct libvlc_instance_t }; -/* - * Event Handling - */ -/* Example usage - * - * struct libvlc_cool_object_t - * { - * ... - * libvlc_event_manager_t * p_event_manager; - * ... - * } - * - * libvlc_my_cool_object_new() - * { - * ... - * p_self->p_event_manager = libvlc_event_manager_new( p_self, - * p_self->p_libvlc_instance, p_e); - * libvlc_event_manager_register_event_type(p_self->p_event_manager, - * libvlc_MyCoolObjectDidSomething, p_e) - * ... - * } - * - * libvlc_my_cool_object_release() - * { - * ... - * libvlc_event_manager_release( p_self->p_event_manager ); - * ... - * } - * - * libvlc_my_cool_object_do_something() - * { - * ... - * libvlc_event_t event; - * event.type = libvlc_MyCoolObjectDidSomething; - * event.u.my_cool_object_did_something.what_it_did = kSomething; - * libvlc_event_send( p_self->p_event_manager, &event ); - * } - * */ - -typedef struct libvlc_event_listener_t -{ - libvlc_event_type_t event_type; - void * p_user_data; - libvlc_callback_t pf_callback; -} libvlc_event_listener_t; - -typedef struct libvlc_event_listeners_group_t -{ - libvlc_event_type_t event_type; - vlc_array_t listeners; - bool b_sublistener_removed; -} libvlc_event_listeners_group_t; - -typedef struct libvlc_event_manager_t -{ - void * p_obj; - struct libvlc_instance_t * p_libvlc_instance; - vlc_array_t listeners_groups; - vlc_mutex_t object_lock; - vlc_mutex_t event_sending_lock; -} libvlc_event_sender_t; - - /*************************************************************************** * Other internal functions ***************************************************************************/ @@ -155,6 +92,11 @@ void libvlc_event_send( libvlc_event_manager_t * p_em, libvlc_event_t * p_event ); +void libvlc_event_attach_async( libvlc_event_manager_t * p_event_manager, + libvlc_event_type_t event_type, + libvlc_callback_t pf_callback, + void *p_user_data, + libvlc_exception_t *p_e ); /* Exception shorcuts */ -- 2.39.2