Fix screensaver deadlock if terminating as soon the interface is created - closes...

[vlc] / modules / misc / screensaver.c

diff --git a/modules/misc/screensaver.c b/modules/misc/screensaver.c
index 166e0daa8fd28647f19b9fd1eacfe59bf7e0ade1..c2d76afc9d04b4265aa52d53aab708a5ee5d4ea4 100644 (file)
--- a/modules/misc/screensaver.c
+++ b/modules/misc/screensaver.c
@@ -32,6 +32,10 @@
 #include <vlc_aout.h>
 #include <vlc_vout.h>
 
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
 #ifdef HAVE_DBUS
 
 #define DBUS_API_SUBJECT_TO_CHANGE
@@ -125,6 +129,33 @@ static void Deactivate( vlc_object_t *p_this )
 #endif
 }
 
+/*****************************************************************************
+ * Execute: Spawns a process using execv()
+ *****************************************************************************/
+static void Execute( intf_thread_t *p_this, const char *const *ppsz_args )
+{
+    pid_t pid;
+    switch( pid = fork() )
+    {
+        case 0:     /* we're the child */
+            /* We don't want output */
+            freopen( "/dev/null", "w", stdout );
+            freopen( "/dev/null", "w", stderr );
+            execv( ppsz_args[0] , (char *const *)ppsz_args );
+            /* If the file we want to execute doesn't exist we exit() */
+            exit( 1 );
+            break;
+        case -1:    /* we're the error */
+            msg_Dbg( p_this, "Couldn't fork() while launching %s",
+                     ppsz_args[0] );
+            break;
+        default:    /* we're the parent */
+            /* Wait for the child to exit.
+             * We will not deadlock because we ran "/bin/sh &" */
+            while( waitpid( pid, NULL, 0 ) != pid);
+            break;
+    }
+}
 
 /*****************************************************************************
  * Run: main thread
@@ -134,22 +165,20 @@ static void Deactivate( vlc_object_t *p_this )
  *****************************************************************************/
 static void Run( intf_thread_t *p_intf )
 {
-    vlc_bool_t b_quit = VLC_FALSE;
+    vlc_object_lock( p_intf );
 
 #ifdef HAVE_DBUS
     p_intf->p_sys->p_connection = dbus_init( p_intf );
 #endif
 
-    while( !b_quit )
+    while( vlc_object_alive( p_intf ) )
     {
+        vlc_object_t *p_vout;
+
         /* Check screensaver every 30 seconds */
-        vlc_mutex_lock( &p_intf->object_lock );
-        vlc_cond_timedwait( &p_intf->object_wait, &p_intf->object_lock,
-                            mdate() + 30000000 );
-        b_quit = p_intf->b_die;
-        vlc_mutex_unlock( &p_intf->object_lock );
+        if( vlc_object_timedwait( p_intf, mdate() + 30000000 ) < 0 )
+            continue;
 
-        vlc_object_t *p_vout;
         p_vout = vlc_object_find( p_intf, VLC_OBJECT_VOUT, FIND_ANYWHERE );
 
         /* If there is a video output, disable xscreensaver */
@@ -163,7 +192,9 @@ static void Run( intf_thread_t *p_intf )
                 if( PLAYING_S == p_input->i_state )
                 {
                     /* http://www.jwz.org/xscreensaver/faq.html#dvd */
-                    system( "xscreensaver-command -deactivate >&- 2>&- &" );
+                    const char *const ppsz_xsargs[] = { "/bin/sh", "-c",
+                            "xscreensaver-command -deactivate &", (char*)NULL };
+                    Execute( p_intf, ppsz_xsargs );
 
                     /* If we have dbus support, let's communicate directly
                        with gnome-screensave else, run
@@ -171,7 +202,9 @@ static void Run( intf_thread_t *p_intf )
 #ifdef HAVE_DBUS
                     poke_screensaver( p_intf, p_intf->p_sys->p_connection );
 #else
-                    system( "gnome-screensaver-command --poke >&- 2>&- &" );
+                    const char *const ppsz_gsargs[] = { "/bin/sh", "-c",
+                            "gnome-screensaver-command --poke &", (char*)NULL };
+                    Execute( p_intf, ppsz_gsargs );
 #endif
                     /* FIXME: add support for other screensavers */
                 }
@@ -179,6 +212,7 @@ static void Run( intf_thread_t *p_intf )
             }
         }
     }
+    vlc_object_unlock( p_intf );
 }
 
 #ifdef HAVE_DBUS