Remove vlc_threads_(init|end), fix thread-safety on Win32

src/libvlc.c

@@ -238,11 +238,6 @@ libvlc_int_t * libvlc_InternalCreate( void )
     libvlc_priv_t *priv;
     char *psz_env = NULL;
 
-    /* vlc_threads_init *must* be the first internal call! No other call is
-     * allowed before the thread system has been initialized. */
-    if (vlc_threads_init ())
-        return NULL;
-
     /* Now that the thread system is initialized, we don't have much, but
      * at least we have variables */
     vlc_mutex_t *lock = var_AcquireMutex( "libvlc" );
@@ -1161,11 +1156,6 @@ int libvlc_InternalDestroy( libvlc_int_t *p_libvlc )
     vlc_object_release( p_libvlc );
     p_libvlc = NULL;
 
-    /* Stop thread system: last one out please shut the door!
-     * The number of initializations of the thread system is counted, we
-     * can call this each time */
-    vlc_threads_end ();
-
     return VLC_SUCCESS;
 }
 

src/libvlc.h

@@ -45,8 +45,6 @@ void system_End       ( libvlc_int_t * );
 /*
  * Threads subsystem
  */
-int vlc_threads_init( void );
-void vlc_threads_end( void );
 
 /* Hopefully, no need to export this. There is a new thread API instead. */
 void vlc_thread_cancel (vlc_object_t *);

src/misc/threads.c

@@ -39,15 +39,8 @@
 #endif
 #include <signal.h>
 
-/*****************************************************************************
- * Global mutex for lazy initialization of the threads system
- *****************************************************************************/
-static volatile unsigned i_initializations = 0;
-
 #if defined( LIBVLC_USE_PTHREAD )
 # include <sched.h>
-
-static pthread_mutex_t once_mutex = PTHREAD_MUTEX_INITIALIZER;
 #else
 static vlc_threadvar_t cancel_key;
 #endif
@@ -56,7 +49,12 @@ static struct
 {
    vlc_dictionary_t list;
    vlc_mutex_t      lock;
-} named_mutexes;
+} named_mutexes = {
+    { 0, NULL, },
+#ifdef LIBVLC_USE_PTHREAD
+    PTHREAD_MUTEX_INITIALIZER,
+#endif
+};
 
 #ifdef HAVE_EXECINFO_H
 # include <execinfo.h>
@@ -158,65 +156,29 @@ typedef struct vlc_cancel_t
 # define VLC_CANCEL_INIT { NULL, true, false }
 #endif
 
-/*****************************************************************************
- * vlc_threads_init: initialize threads system
- *****************************************************************************
- * This function requires lazy initialization of a global lock in order to
- * keep the library really thread-safe. Some architectures don't support this
- * and thus do not guarantee the complete reentrancy.
- *****************************************************************************/
-int vlc_threads_init( void )
+#ifdef WIN32
+BOOL WINAPI DllMain (HINSTANCE hinstDll, DWORD fdwReason, LPVOID lpvReserved)
 {
-    /* If we have lazy mutex initialization, use it. Otherwise, we just
-     * hope nothing wrong happens. */
-#if defined( LIBVLC_USE_PTHREAD )
-    pthread_mutex_lock( &once_mutex );
-#endif
+    (void) hinstDll;
+    (void) lpvReserved;
 
-    if( i_initializations == 0 )
+    switch (fdwReason)
     {
-        vlc_dictionary_init (&named_mutexes.list, 0);
-        vlc_mutex_init (&named_mutexes.lock);
-#ifndef LIBVLC_USE_PTHREAD_CANCEL
-        vlc_threadvar_create( &cancel_key, free );
-#endif
-    }
-    i_initializations++;
-
-#if defined( LIBVLC_USE_PTHREAD )
-    pthread_mutex_unlock( &once_mutex );
-#endif
-
-    return VLC_SUCCESS;
-}
-
-/*****************************************************************************
- * vlc_threads_end: stop threads system
- *****************************************************************************
- * FIXME: This function is far from being threadsafe.
- *****************************************************************************/
-void vlc_threads_end( void )
-{
-#if defined( LIBVLC_USE_PTHREAD )
-    pthread_mutex_lock( &once_mutex );
-#endif
-
-    assert( i_initializations > 0 );
+        case DLL_PROCESS_ATTACH:
+            vlc_dictionary_init (&named_mutexes.list, 0);
+            vlc_mutex_init (&named_mutexes.lock);
+            vlc_threadvar_create (&cancel_key, free);
+            break;
 
-    if( i_initializations == 1 )
-    {
-#ifndef LIBVLC_USE_PTHREAD
-        vlc_threadvar_delete( &cancel_key );
-#endif
-        vlc_mutex_destroy (&named_mutexes.lock);
-        vlc_dictionary_clear (&named_mutexes.list);
+        case DLL_PROCESS_DETACH:
+            vlc_threadvar_delete( &cancel_key );
+            vlc_mutex_destroy (&named_mutexes.lock);
+            vlc_dictionary_clear (&named_mutexes.list);
+            break;
     }
-    i_initializations--;
-
-#if defined( LIBVLC_USE_PTHREAD )
-    pthread_mutex_unlock( &once_mutex );
-#endif
+    return TRUE;
 }
+#endif
 
 #if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
 /* This is not prototyped under glibc, though it exists. */