[vlc-devel] commit: Fix some race conditions in the module bank ( Rémi Denis-Courmont )
git version control
git at videolan.org
Sun Oct 5 15:43:42 CEST 2008
vlc | branch: master | Rémi Denis-Courmont <rdenis at simphalempin.com> | Sun Oct 5 16:33:28 2008 +0300| [89ea9a8dedde81e80a476ff2e54ed249a7a614cf] | committer: Rémi Denis-Courmont
Fix some race conditions in the module bank
Unfortunately(?), these only occur in multi-instances scenarii...
> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=89ea9a8dedde81e80a476ff2e54ed249a7a614cf
---
src/modules/modules.c | 57 +++++++++++++++++++++++++------------------------
1 files changed, 29 insertions(+), 28 deletions(-)
diff --git a/src/modules/modules.c b/src/modules/modules.c
index 33c335d..f6d7fc3 100644
--- a/src/modules/modules.c
+++ b/src/modules/modules.c
@@ -91,6 +91,7 @@
#include "modules/builtin.h"
static module_bank_t *p_module_bank = NULL;
+static vlc_mutex_t module_lock = VLC_STATIC_MUTEX;
/*****************************************************************************
* Local prototypes
@@ -102,7 +103,7 @@ static int AllocatePluginFile ( vlc_object_t *, char *, int64_t, int64_t );
static module_t * AllocatePlugin( vlc_object_t *, char * );
#endif
static int AllocateBuiltinModule( vlc_object_t *, int ( * ) ( module_t * ) );
-static void DeleteModule ( module_t * );
+static void DeleteModule ( module_bank_t *, module_t * );
#ifdef HAVE_DYNAMIC_PLUGINS
static void DupModule ( module_t * );
static void UndupModule ( module_t * );
@@ -120,7 +121,7 @@ void __module_InitBank( vlc_object_t *p_this )
{
module_bank_t *p_bank = NULL;
- vlc_mutex_lock( &global_lock );
+ vlc_mutex_lock( &module_lock );
if( p_module_bank == NULL )
{
@@ -144,7 +145,7 @@ void __module_InitBank( vlc_object_t *p_this )
else
p_module_bank->i_usage++;
- vlc_mutex_unlock( &global_lock );
+ vlc_mutex_unlock( &module_lock );
}
@@ -160,28 +161,28 @@ void __module_EndBank( vlc_object_t *p_this )
{
module_bank_t *p_bank;
- vlc_mutex_lock( &global_lock );
+ /* Save the configuration */
+ config_AutoSaveConfigFile( p_this );
+
+ vlc_mutex_lock( &module_lock );
p_bank = p_module_bank;
assert (p_bank != NULL);
if( --p_bank->i_usage > 0 )
{
- vlc_mutex_unlock( &global_lock );
+ vlc_mutex_unlock( &module_lock );
return;
}
- /*FIXME: For thread safety, we need to:
- p_module_bank = NULL; - immediately, but that will crash the cache */
- vlc_mutex_unlock( &global_lock );
-
- /* Save the configuration */
- config_AutoSaveConfigFile( p_this );
+ p_module_bank = NULL;
+ vlc_mutex_unlock( &module_lock );
#ifdef HAVE_DYNAMIC_PLUGINS
- if( p_bank->b_cache ) CacheSave( p_this, p_module_bank );
+ if( p_bank->b_cache )
+ CacheSave( p_this, p_bank );
while( p_bank->i_loaded_cache-- )
{
if( p_bank->pp_loaded_cache[p_bank->i_loaded_cache] )
{
- DeleteModule(
+ DeleteModule( p_bank,
p_bank->pp_loaded_cache[p_bank->i_loaded_cache]->p_module );
free( p_bank->pp_loaded_cache[p_bank->i_loaded_cache]->psz_file );
free( p_bank->pp_loaded_cache[p_bank->i_loaded_cache] );
@@ -207,9 +208,8 @@ void __module_EndBank( vlc_object_t *p_this )
#endif
while( p_bank->head != NULL )
- DeleteModule( p_bank->head );
+ DeleteModule( p_bank, p_bank->head );
- p_module_bank = NULL; /* FIXME: do this inside the lock */
free( p_bank );
}
@@ -222,16 +222,17 @@ void __module_EndBank( vlc_object_t *p_this )
*/
void __module_LoadBuiltins( vlc_object_t * p_this )
{
- vlc_mutex_lock( &global_lock );
+ vlc_mutex_lock( &module_lock );
if( p_module_bank->b_builtins )
{
- vlc_mutex_unlock( &global_lock );
+ vlc_mutex_unlock( &module_lock );
return;
}
p_module_bank->b_builtins = true;
- vlc_mutex_unlock( &global_lock );
+ vlc_mutex_unlock( &module_lock );
msg_Dbg( p_this, "checking builtin modules" );
+ /* FIXME: race here - do this under the lock!! */
ALLOCATE_ALL_BUILTINS();
}
@@ -247,23 +248,22 @@ void __module_LoadBuiltins( vlc_object_t * p_this )
void module_LoadPlugins( vlc_object_t * p_this, bool b_cache_delete )
{
#ifdef HAVE_DYNAMIC_PLUGINS
- vlc_mutex_lock( &global_lock );
+ vlc_mutex_lock( &module_lock );
if( p_module_bank->b_plugins )
{
- vlc_mutex_unlock( &global_lock );
+ vlc_mutex_unlock( &module_lock );
return;
}
p_module_bank->b_plugins = true;
- vlc_mutex_unlock( &global_lock );
+ vlc_mutex_unlock( &module_lock );
msg_Dbg( p_this, "checking plugin modules" );
-
- if( config_GetInt( p_this, "plugins-cache" ) )
- p_module_bank->b_cache = true;
+ p_module_bank->b_cache = config_GetInt( p_this, "plugins-cache" ) > 0;
if( p_module_bank->b_cache || b_cache_delete )
CacheLoad( p_this, p_module_bank, b_cache_delete );
+ /* FIXME: race - do this under the lock */
AllocateAllPlugins( p_this );
#endif
}
@@ -330,7 +330,7 @@ void module_release (module_t *m)
/**
* Frees the flat list of VLC modules.
- * @param list list obtained by module_list_get
+ * @param list list obtained by module_list_get()
* @param length number of items on the list
* @return nothing.
*/
@@ -357,6 +357,7 @@ module_t **module_list_get (size_t *n)
module_t **tab = NULL;
size_t i = 0;
+ assert (p_module_bank);
for (module_t *mod = p_module_bank->head; mod; mod = mod->next)
{
module_t **nt;
@@ -562,7 +563,7 @@ found_shortcut:
if( p_new_module )
{
CacheMerge( p_this, p_real, p_new_module );
- DeleteModule( p_new_module );
+ DeleteModule( p_module_bank, p_new_module );
}
}
#endif
@@ -1333,12 +1334,12 @@ static int AllocateBuiltinModule( vlc_object_t * p_this,
*****************************************************************************
* This function can only be called if the module isn't being used.
*****************************************************************************/
-static void DeleteModule( module_t * p_module )
+static void DeleteModule( module_bank_t *p_bank, module_t * p_module )
{
assert( p_module );
/* Unlist the module (if it is in the list) */
- module_t **pp_self = &p_module_bank->head;
+ module_t **pp_self = &p_bank->head;
while (*pp_self != NULL && *pp_self != p_module)
pp_self = &((*pp_self)->next);
if (*pp_self)
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