playlist: randomize in a thread-safe manner

src/playlist/sort.c

@@ -27,6 +27,7 @@
 #endif
 
 #include <vlc_common.h>
+#include <vlc_rand.h>
 #define  VLC_INTERNAL_PLAYLIST_SORT_FUNCTIONS
 #include "vlc_playlist.h"
 #include "playlist_internal.h"
@@ -146,7 +147,7 @@ void playlist_ItemArraySort( unsigned i_items, playlist_item_t **pp_items,
 
         for( i_position = i_items - 1; i_position > 0; i_position-- )
         {
-            i_new = rand() % (i_position+1);
+            i_new = ((unsigned)vlc_mrand48()) % (i_position+1);
             p_temp = pp_items[i_position];
             pp_items[i_position] = pp_items[i_new];
             pp_items[i_new] = p_temp;

src/playlist/thread.c

@@ -32,6 +32,7 @@
 #include <vlc_input.h>
 #include <vlc_interface.h>
 #include <vlc_playlist.h>
+#include <vlc_rand.h>
 #include "stream_output/stream_output.h"
 #include "playlist_internal.h"
 
@@ -189,10 +190,9 @@ static void ResetCurrentlyPlaying( playlist_t *p_playlist,
     if( var_GetBool( p_playlist, "random" ) )
     {
         /* Shuffle the array */
-        srand( (unsigned int)mdate() );
-        for( int j = p_playlist->current.i_size - 1; j > 0; j-- )
+        for( unsigned j = p_playlist->current.i_size - 1; j > 0; j-- )
         {
-            int i = rand() % (j+1); /* between 0 and j */
+            unsigned i = ((unsigned)vlc_mrand48()) % (j+1); /* between 0 and j */
             playlist_item_t *p_tmp;
             /* swap the two items */
             p_tmp = ARRAY_VAL(p_playlist->current, i);