msg_Subscribe: expose structure to plugins

This eliminates one error case that nobody dealt with anyway.

include/vlc_interface.h

@@ -107,11 +107,6 @@ VLC_API void libvlc_Quit( libvlc_int_t * );
  * @{
  */
 
-/**
- * Used by interface plugins which subscribe to the message bank.
- */
-typedef struct msg_subscription_t msg_subscription_t;
-
 /**
  * Message logging callback signature.
  * Accepts one private data pointer, the message, and an overrun counter.
@@ -119,7 +114,17 @@ typedef struct msg_subscription_t msg_subscription_t;
 typedef void (*msg_callback_t) (void *, int, const msg_item_t *,
                                 const char *, va_list);
 
-VLC_API msg_subscription_t *vlc_Subscribe(msg_callback_t, void *) VLC_USED;
+/**
+ * Used by interface plugins which subscribe to the message bank.
+ */
+typedef struct msg_subscription
+{
+    struct msg_subscription *prev, *next;
+    msg_callback_t func;
+    void *opaque;
+} msg_subscription_t;
+
+VLC_API void vlc_Subscribe(msg_subscription_t *, msg_callback_t, void *);
 VLC_API void vlc_Unsubscribe(msg_subscription_t *);
 
 /*@}*/

modules/gui/macosx/intf.h

@@ -75,7 +75,7 @@ struct intf_sys_t
     bool b_vout_update;
 
     /* The messages window */
-    msg_subscription_t * p_sub;
+    msg_subscription_t sub;
 };
 
 /*****************************************************************************

modules/gui/macosx/intf.m

@@ -106,7 +106,7 @@ int OpenIntf ( vlc_object_t *p_this )
     memset( p_intf->p_sys, 0, sizeof( *p_intf->p_sys ) );
 
     /* subscribe to LibVLCCore's messages */
-    p_intf->p_sys->p_sub = vlc_Subscribe( MsgCallback, NULL );
+    vlc_Subscribe( &p_intf->p_sys->sub, MsgCallback, NULL );
     p_intf->pf_run = Run;
     p_intf->b_should_run_on_first_thread = true;
 
@@ -775,7 +775,7 @@ static VLCMain *_o_sharedMainInstance = nil;
     [o_eyetv release];
 
     /* unsubscribe from libvlc's debug messages */
-    vlc_Unsubscribe( p_intf->p_sys->p_sub );
+    vlc_Unsubscribe( &p_intf->p_sys->sub );
 
     [o_msg_arr removeAllObjects];
     [o_msg_arr release];

modules/gui/ncurses.c

@@ -190,7 +190,7 @@ struct intf_sys_t
     int             box_start;        // first line of box displayed
     int             box_idx;          // selected line
 
-    msg_subscription_t  *sub;         // message bank subscription
+    msg_subscription_t sub;         // message bank subscription
     struct
     {
         int              type;
@@ -1789,7 +1789,7 @@ static int Open(vlc_object_t *p_this)
     vlc_mutex_init(&sys->pl_lock);
 
     sys->verbosity = var_InheritInteger(intf, "verbose");
-    sys->sub = vlc_Subscribe(MsgCallback, sys);
+    vlc_Subscribe(&sys->sub, MsgCallback, sys);
 
     sys->box_type = BOX_PLAYLIST;
     sys->plidx_follow = true;
@@ -1842,7 +1842,7 @@ static void Close(vlc_object_t *p_this)
 
     endwin();   /* Close the ncurses interface */
 
-    vlc_Unsubscribe(sys->sub);
+    vlc_Unsubscribe(&sys->sub);
     vlc_mutex_destroy(&sys->msg_lock);
     vlc_mutex_destroy(&sys->pl_lock);
     for(unsigned i = 0; i < sizeof sys->msgs / sizeof *sys->msgs; i++) {

modules/gui/qt4/dialogs/messages.cpp

@@ -121,13 +121,13 @@ MessagesDialog::MessagesDialog( intf_thread_t *_p_intf)
     readSettings( "Messages", QSize( 600, 450 ) );
 
     /* Hook up to LibVLC messaging */
-    sub = vlc_Subscribe( MsgCallback, this );
+    vlc_Subscribe( &sub, MsgCallback, this );
 }
 
 MessagesDialog::~MessagesDialog()
 {
     writeSettings( "Messages" );
-    vlc_Unsubscribe( sub );
+    vlc_Unsubscribe( &sub );
 };
 
 void MessagesDialog::changeVerbosity( int i_verbosity )

modules/gui/qt4/dialogs/messages.hpp

@@ -48,7 +48,7 @@ private:
     virtual ~MessagesDialog();
 
     Ui::messagesPanelWidget ui;
-    msg_subscription_t *sub;
+    msg_subscription_t sub;
     static void sinkMessage( void *, msg_item_t *, unsigned );
     void customEvent( QEvent * );
     void sinkMessage( const MsgEvent * );

modules/misc/logger.c

@@ -74,7 +74,7 @@
  *****************************************************************************/
 struct intf_sys_t
 {
-    msg_subscription_t *p_sub;
+    msg_subscription_t sub;
     FILE *p_file;
     const char *footer;
 };
@@ -298,7 +298,7 @@ static int Open( vlc_object_t *p_this )
         fputs( header, p_sys->p_file );
     }
 
-    p_sys->p_sub = vlc_Subscribe( cb, p_intf );
+    vlc_Subscribe( &p_sys->sub, cb, p_intf );
     return VLC_SUCCESS;
 }
 
@@ -311,7 +311,7 @@ static void Close( vlc_object_t *p_this )
     intf_sys_t *p_sys = p_intf->p_sys;
 
     /* Flush the queue and unsubscribe from the message queue */
-    vlc_Unsubscribe( p_sys->p_sub );
+    vlc_Unsubscribe( &p_sys->sub );
 
     /* Close the log file */
 #ifdef HAVE_SYSLOG_H

src/misc/messages.c

@@ -55,13 +55,6 @@
 vlc_rwlock_t msg_lock = VLC_STATIC_RWLOCK;
 msg_subscription_t *msg_head;
 
-struct msg_subscription_t
-{
-    msg_subscription_t *prev, *next;
-    msg_callback_t  func;
-    void           *opaque;
-};
-
 /**
  * Subscribe to the message queue.
  * Whenever a message is emitted, a callback will be called.
@@ -69,14 +62,9 @@ struct msg_subscription_t
  *
  * @param cb callback function
  * @param opaque data for the callback function
- * @return a subscription pointer, or NULL in case of failure
  */
-msg_subscription_t *vlc_Subscribe (msg_callback_t cb, void *opaque)
+void vlc_Subscribe (msg_subscription_t *sub, msg_callback_t cb, void *opaque)
 {
-    msg_subscription_t *sub = malloc (sizeof (*sub));
-    if (sub == NULL)
-        return NULL;
-
     sub->prev = NULL;
     sub->func = cb;
     sub->opaque = opaque;
@@ -85,8 +73,6 @@ msg_subscription_t *vlc_Subscribe (msg_callback_t cb, void *opaque)
     sub->next = msg_head;
     msg_head = sub;
     vlc_rwlock_unlock (&msg_lock);
-
-    return sub;
 }
 
 /**
@@ -106,7 +92,6 @@ void vlc_Unsubscribe (msg_subscription_t *sub)
         msg_head = sub->next;
     }
     vlc_rwlock_unlock (&msg_lock);
-    free (sub);
 }
 
 /**