From 737c32b9b6d0ff3a9a19803022a154f1d8c7cce1 Mon Sep 17 00:00:00 2001
From: robert <robert.ayrapetyan@gmail.com>
Date: Mon, 16 Oct 2023 20:53:49 +0000
Subject: [PATCH] ximagesrc: fix compile-time warning and XInitThreads()

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5493>
---
 .../gst-plugins-good/sys/ximage/gstximagesrc.c    | 15 +++++++++++----
 subprojects/gstreamer/docs/gst/running.md         |  7 +++++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/subprojects/gst-plugins-good/sys/ximage/gstximagesrc.c b/subprojects/gst-plugins-good/sys/ximage/gstximagesrc.c
index 256d0eed79..895816abfe 100644
--- a/subprojects/gst-plugins-good/sys/ximage/gstximagesrc.c
+++ b/subprojects/gst-plugins-good/sys/ximage/gstximagesrc.c
@@ -22,11 +22,18 @@
  * SECTION:element-ximagesrc
  * @title: ximagesrc
  *
- * This element captures your X Display and creates raw RGB video.  It uses
+ * This element captures your X Display and creates raw RGB video. It uses
  * the XDamage extension if available to only capture areas of the screen that
  * have changed since the last frame. It uses the XFixes extension if
  * available to also capture your mouse pointer. It supports handling of
  * mouse and keyboard events. By default it will fixate to 25 frames per second.
+ * 
+ * Applications are expected to call `XinitThreads()` before any other threads
+ * are started. For use in gst-launch-1.0 or other GStreamer command line 
+ * applications it is also possible to set the GST_XINITTHREADS=1 environment 
+ * variable so that `XInitThreads()` gets called when the plugin is loaded. This 
+ * may be too late in other use case scenarios though, so applications should 
+ * not rely on that.
  *
  * ## Example pipelines
  * |[
@@ -1398,10 +1405,7 @@ gst_ximage_src_class_init (GstXImageSrcClass * klass)
   bc->stop = gst_ximage_src_stop;
   bc->unlock = gst_ximage_src_unlock;
   push_class->create = gst_ximage_src_create;
-#ifdef HAVE_NAVIGATION
-  XInitThreads ();
   bc->event = gst_ximage_src_event;
-#endif /* HAVE_NAVIGATION */
 }
 
 static void
@@ -1429,6 +1433,9 @@ plugin_init (GstPlugin * plugin)
 {
   gboolean ret;
 
+  if (g_getenv ("GST_XINITTHREADS"))
+    XInitThreads ();
+
   GST_DEBUG_CATEGORY_INIT (gst_debug_ximage_src, "ximagesrc", 0,
       "ximagesrc element debug");
 
diff --git a/subprojects/gstreamer/docs/gst/running.md b/subprojects/gstreamer/docs/gst/running.md
index 436a7900d3..8285cd2329 100644
--- a/subprojects/gstreamer/docs/gst/running.md
+++ b/subprojects/gstreamer/docs/gst/running.md
@@ -343,3 +343,10 @@ Example: `GST_PLUGIN_FEATURE_RANK=foo:PRIMARY,bar:primary,foobar:128`
 As a result of the above example,
 the `foo` and` bar` plugin feature rank values are `PRIMARY`(256)
 and `SECONDARY`(128) rank value will be assigned to `foobar`.
+
+**`GST_XINITTHREADS`.**
+
+Set this variable when using components that rely on X11, such as ximagesrc, 
+from gst-launch-1.0 or other command line applications. However, applications 
+should not depend on this variable and should make their own `XInitThreads()`
+call as early as possible.