[vlc-commits] commit: Xlib: check if we can call XInitThreads() before we do so ( =?UTF-8?Q?R=C3=A9mi=20Denis=2DCourmont=20?=)

[git at videolan.org]

vlc/vlc-1.1 | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Sun Dec  5 01:17:10 2010 +0200| [39468dd6cbfca20eb0b4b1f278f70a874248c6f5] | committer: Rémi Denis-Courmont 

Xlib: check if we can call XInitThreads() before we do so

Parental advisory: naked kludge and explicit hack
(cherry picked from commit abbdcb63d9f4161055e24faec1c7edcc9b83e44c)

> http://git.videolan.org/gitweb.cgi/vlc/vlc-1.1.git/?a=commit;h=39468dd6cbfca20eb0b4b1f278f70a874248c6f5
---

 include/vlc_xlib.h |   20 ++++++++++++++++++--
 1 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/include/vlc_xlib.h b/include/vlc_xlib.h
index 4e3632c..969dcbc 100644
--- a/include/vlc_xlib.h
+++ b/include/vlc_xlib.h
@@ -21,7 +21,10 @@
 #ifndef VLC_XLIB_H
 # define VLC_XLIB_H 1
 
+# include <stdio.h>
+# include <stdlib.h>
 # include <X11/Xlib.h>
+# include <X11/Xlibint.h>
 
 static inline bool vlc_xlib_init (vlc_object_t *obj)
 {
@@ -30,9 +33,22 @@ static inline bool vlc_xlib_init (vlc_object_t *obj)
     if (var_InheritBool (obj, "xlib"))
     {
         /* XInitThreads() can be called multiple times,
-         * but it is not reentrant. */
+         * but it is not reentrant, so we need this global lock. */
         vlc_global_lock (VLC_XLIB_MUTEX);
-        ok = XInitThreads () != 0;
+
+        if (_Xglobal_lock == NULL && unlikely(_XErrorFunction != NULL))
+        {
+            /* (_Xglobal_lock == NULL) => Xlib threads not initialized */
+            /* (_XErrorFunction != NULL) => Xlib already in use */
+            fprintf (stderr, "%s:%u:%u: Xlib not initialized for threads.\n"
+                     "This process is probably using LibVLC incorrectly.\n"
+                     "Pass \"--no-xlib\" to libvlc_new() to fix this.\n",
+                     __FILE__, __LINE__, __func__);
+            /* Initiate core meltdown */
+            abort ();
+        }
+        else
+            ok = XInitThreads () != 0;
         vlc_global_unlock (VLC_XLIB_MUTEX);
     }
     return ok;