[vlc-devel] commit: Use a doubly-linked list for objects instead of a flat table ( Rémi Denis-Courmont )
git version control
git at videolan.org
Wed May 28 19:21:06 CEST 2008
vlc | branch: master | Rémi Denis-Courmont <rem at videolan.org> | Wed May 28 20:22:34 2008 +0300| [0d37c5b11c5226f990a48d4617f4b70527bb50b3]
Use a doubly-linked list for objects instead of a flat table
Speeds up object creation and deletion, slows down vlc_object_get (which
you should not use anyway, remember), makes no difference for the rest
> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=0d37c5b11c5226f990a48d4617f4b70527bb50b3
---
src/libvlc.h | 4 +-
src/misc/objects.c | 156 ++++++++++++----------------------------------------
2 files changed, 38 insertions(+), 122 deletions(-)
diff --git a/src/libvlc.h b/src/libvlc.h
index 85f62df..f23490c 100644
--- a/src/libvlc.h
+++ b/src/libvlc.h
@@ -149,8 +149,6 @@ typedef struct libvlc_global_data_t
/* Object structure data */
int i_counter; ///< object counter
- int i_objects; ///< Attached objects count
- vlc_object_t ** pp_objects; ///< Array of all objects
module_bank_t * p_module_bank; ///< The module bank
@@ -184,6 +182,8 @@ struct vlc_object_internals_t
unsigned i_refcount;
vlc_destructor_t pf_destructor;
+ /* Objects tree structure */
+ vlc_object_t *prev, *next;
vlc_object_t **pp_children;
int i_children;
};
diff --git a/src/misc/objects.c b/src/misc/objects.c
index 043fd9e..06177dc 100644
--- a/src/misc/objects.c
+++ b/src/misc/objects.c
@@ -72,7 +72,6 @@ static vlc_object_t * FindObject ( vlc_object_t *, int, int );
static vlc_object_t * FindObjectName( vlc_object_t *, const char *, int );
static void PrintObject ( vlc_object_t *, const char * );
static void DumpStructure ( vlc_object_t *, int, char * );
-static int FindIndex ( vlc_object_t *, vlc_object_t **, int );
static vlc_list_t * NewList ( int );
static void ListReplace ( vlc_list_t *, vlc_object_t *, int );
@@ -141,8 +140,7 @@ void *vlc_custom_create( vlc_object_t *p_this, size_t i_size,
p_new->p_libvlc = NULL;
p_libvlc_global->i_counter = 0;
- p_libvlc_global->i_objects = 0;
- p_libvlc_global->pp_objects = NULL;
+ p_priv->next = p_priv->prev = p_new;
vlc_mutex_init( &structure_lock );
}
else
@@ -171,12 +169,12 @@ void *vlc_custom_create( vlc_object_t *p_this, size_t i_size,
vlc_spin_init( &p_priv->spin );
p_priv->pipes[0] = p_priv->pipes[1] = -1;
+ p_priv->next = VLC_OBJECT (p_libvlc_global);
vlc_mutex_lock( &structure_lock );
+ p_priv->prev = vlc_internals (p_libvlc_global)->prev;
+ vlc_internals (p_libvlc_global)->prev = p_new;
+ vlc_internals (p_priv->prev)->next = p_new;
p_new->i_object_id = p_libvlc_global->i_counter++;
- /* Wooohaa! If *this* fails, we're in serious trouble! Anyway it's
- * useless to try and recover anything if pp_objects gets smashed. */
- TAB_APPEND( p_libvlc_global->i_objects, p_libvlc_global->pp_objects,
- p_new );
vlc_mutex_unlock( &structure_lock );
if( i_type == VLC_OBJECT_LIBVLC )
@@ -340,36 +338,30 @@ static void vlc_object_destroy( vlc_object_t *p_this )
#ifndef NDEBUG
assert( p_global == vlc_global() );
/* Test for leaks */
- if( p_global->i_objects > 0 )
+ for( vlc_object_t *leaked = p_priv->next;
+ leaked != p_this;
+ leaked = vlc_internals (leaked)->next )
{
- int i;
- for( i = 0; i < p_global->i_objects; i++ )
- {
- /* We are leaking this object */
- fprintf( stderr,
- "ERROR: leaking object (id:%i, type:%s, name:%s)\n",
- p_global->pp_objects[i]->i_object_id,
- p_global->pp_objects[i]->psz_object_type,
- p_global->pp_objects[i]->psz_object_name );
-
- /* Dump libvlc object to ease debugging */
- vlc_object_dump( p_global->pp_objects[i] );
-
- fflush(stderr);
- }
+ /* We are leaking this object */
+ fprintf( stderr,
+ "ERROR: leaking object (id:%i, type:%s, name:%s)\n",
+ leaked->i_object_id, leaked->psz_object_type,
+ leaked->psz_object_name );
+ /* Dump libvlc object to ease debugging */
+ vlc_object_dump( leaked );
+ fflush(stderr);
+ }
+ if( p_priv->next != p_this )
+ {
/* Dump libvlc object to ease debugging */
vlc_object_dump( p_this );
-
/* Strongly abort, cause we want these to be fixed */
abort();
}
#endif
/* We are the global object ... no need to lock. */
- free( p_global->pp_objects );
- p_global->pp_objects = NULL;
-
vlc_mutex_destroy( &structure_lock );
}
@@ -644,47 +636,19 @@ void __vlc_object_kill( vlc_object_t *p_this )
*/
void * vlc_object_get( int i_id )
{
- int i_max, i_middle;
- vlc_object_t **pp_objects;
libvlc_global_data_t *p_libvlc_global = vlc_global();
vlc_object_t *obj = NULL;
vlc_mutex_lock( &structure_lock );
- pp_objects = p_libvlc_global->pp_objects;
-
- /* Perform our dichotomy */
- for( i_max = p_libvlc_global->i_objects - 1 ; ; )
+ for( obj = vlc_internals (p_libvlc_global)->next;
+ obj != VLC_OBJECT (p_libvlc_global);
+ obj = vlc_internals (obj)->next )
{
- i_middle = i_max / 2;
-
- if( pp_objects[i_middle]->i_object_id > i_id )
+ if( obj->i_object_id == i_id )
{
- i_max = i_middle;
- }
- else if( pp_objects[i_middle]->i_object_id < i_id )
- {
- if( i_middle )
- {
- pp_objects += i_middle;
- i_max -= i_middle;
- }
- else
- {
- /* This happens when there are only two remaining objects */
- if( pp_objects[i_middle+1]->i_object_id == i_id )
- {
- vlc_object_yield( pp_objects[i_middle+1] );
- obj = pp_objects[i_middle+1];
- }
- break;
- }
- }
- else
- {
- vlc_object_yield( pp_objects[i_middle] );
- obj = pp_objects[i_middle];
- break;
+ vlc_object_yield( obj );
+ return obj;
}
}
@@ -829,15 +793,10 @@ void __vlc_object_release( vlc_object_t *p_this )
if( b_should_destroy )
{
- /* Remove the object from the table
+ /* Remove the object from object list
* so that it cannot be encountered by vlc_object_get() */
- libvlc_global_data_t *p_libvlc_global = vlc_global();
- int i_index;
-
- i_index = FindIndex( p_this, p_libvlc_global->pp_objects,
- p_libvlc_global->i_objects );
- REMOVE_ELEM( p_libvlc_global->pp_objects,
- p_libvlc_global->i_objects, i_index );
+ vlc_internals (internals->next)->prev = internals->prev;
+ vlc_internals (internals->prev)->next = internals->next;
/* Detach from parent to protect against FIND_CHILDREN */
vlc_object_detach_unlocked (p_this);
@@ -1023,21 +982,18 @@ vlc_list_t *__vlc_list_children( vlc_object_t *obj )
static int DumpCommand( vlc_object_t *p_this, char const *psz_cmd,
vlc_value_t oldval, vlc_value_t newval, void *p_data )
{
- libvlc_global_data_t *p_libvlc_global = vlc_global();
-
(void)oldval; (void)p_data;
if( *psz_cmd == 'l' )
{
- vlc_mutex_lock( &structure_lock );
-
- vlc_object_t **pp_current, **pp_end;
-
- pp_current = p_libvlc_global->pp_objects;
- pp_end = pp_current + p_libvlc_global->i_objects;
-
- for( ; pp_current < pp_end ; pp_current++ )
- PrintObject( *pp_current, "" );
+ vlc_object_t *root = VLC_OBJECT (vlc_global ()), *cur = root;
+ vlc_mutex_lock( &structure_lock );
+ do
+ {
+ PrintObject (cur, "");
+ cur = vlc_internals (cur)->next;
+ }
+ while (cur != root);
vlc_mutex_unlock( &structure_lock );
}
else
@@ -1212,46 +1168,6 @@ void __vlc_object_dump( vlc_object_t *p_this )
/* Following functions are local */
-/*****************************************************************************
- * FindIndex: find the index of an object in an array of objects
- *****************************************************************************
- * This function assumes that p_this can be found in pp_objects. It will not
- * crash if p_this cannot be found, but will return a wrong value. It is your
- * duty to check the return value if you are not certain that the object could
- * be found for sure.
- *****************************************************************************/
-static int FindIndex( vlc_object_t *p_this,
- vlc_object_t **pp_objects, int i_count )
-{
- int i_middle = i_count / 2;
-
- if( i_count == 0 )
- {
- return 0;
- }
-
- if( pp_objects[i_middle] == p_this )
- {
- return i_middle;
- }
-
- if( i_count == 1 )
- {
- return 0;
- }
-
- /* We take advantage of the sorted array */
- if( pp_objects[i_middle]->i_object_id < p_this->i_object_id )
- {
- return i_middle + FindIndex( p_this, pp_objects + i_middle,
- i_count - i_middle );
- }
- else
- {
- return FindIndex( p_this, pp_objects, i_middle );
- }
-}
-
static vlc_object_t * FindObject( vlc_object_t *p_this, int i_type, int i_mode )
{
int i;
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