gldisplay: make readding the same context a no-op

With e38af2304427db908a16bbae0e60aa68be1ba5b5 returning the correct contexts,
gst_gl_display_add_context() was susceptible to causing infinte loops when
adding the same GstGLContext more than once.  Fix and add a test for
gst_gl_display_add_context().

Fixes glvideomixer gst-validate tests.

2 files changed, 100 insertions, 1 deletions

diff --git a/gst-libs/gst/gl/gstgldisplay.c b/gst-libs/gst/gl/gstgldisplay.c
index 65ce1a301..5cae2f4b9 100644
--- a/gst-libs/gst/gl/gstgldisplay.c
+++ b/gst-libs/gst/gl/gstgldisplay.c
@@ -500,7 +500,7 @@ _check_collision (GstGLContext * context, GstGLContext * collision)
     goto out;
   }
 
-  if (collision == context) {
+  if (thread == collision_thread) {
     ret = TRUE;
     goto out;
   }
@@ -546,6 +546,13 @@ gst_gl_display_add_context (GstGLDisplay * display, GstGLContext * context)
   if (thread) {
     collision = _get_gl_context_for_thread_unlocked (display, thread);
     g_thread_unref (thread);
+
+    /* adding the same context is a no-op */
+    if (context == collision) {
+      ret = TRUE;
+      goto out;
+    }
+
     if (_check_collision (context, collision)) {
       ret = FALSE;
       goto out;
diff --git a/tests/check/libs/gstglcontext.c b/tests/check/libs/gstglcontext.c
index e626f2a7d..f2f27f8e0 100644
--- a/tests/check/libs/gstglcontext.c
+++ b/tests/check/libs/gstglcontext.c
@@ -517,6 +517,97 @@ GST_START_TEST (test_is_shared)
 
 GST_END_TEST;
 
+GST_START_TEST (test_display_list)
+{
+  GstGLContext *c1, *c2;
+  GError *error = NULL;
+
+  c1 = gst_gl_context_new (display);
+  gst_gl_context_create (c1, NULL, &error);
+  fail_if (error != NULL, "Error creating context %s\n",
+      error ? error->message : "Unknown Error");
+
+  GST_OBJECT_LOCK (display);
+  {
+    /* no context added so get should return NULL */
+    GstGLContext *tmp =
+        gst_gl_display_get_gl_context_for_thread (display, NULL);
+    fail_unless (tmp == NULL);
+  }
+
+  fail_unless (gst_gl_display_add_context (display, c1));
+  /* re-adding the same context is a no-op */
+  fail_unless (gst_gl_display_add_context (display, c1));
+
+  {
+    GThread *thread;
+    GstGLContext *tmp;
+
+    thread = gst_gl_context_get_thread (c1);
+    fail_unless (thread != NULL);
+
+    tmp = gst_gl_display_get_gl_context_for_thread (display, thread);
+    fail_unless (tmp == c1);
+    g_thread_unref (thread);
+    gst_object_unref (tmp);
+
+    tmp = gst_gl_display_get_gl_context_for_thread (display, NULL);
+    fail_unless (tmp == c1);
+    gst_object_unref (tmp);
+  }
+
+  c2 = gst_gl_context_new (display);
+  gst_gl_context_create (c2, c1, &error);
+  fail_if (error != NULL, "Error creating context %s\n",
+      error ? error->message : "Unknown Error");
+
+  fail_unless (gst_gl_display_add_context (display, c2));
+  /* re-adding the same context is a no-op */
+  fail_unless (gst_gl_display_add_context (display, c2));
+
+  {
+    GThread *thread;
+    GstGLContext *tmp;
+
+    thread = gst_gl_context_get_thread (c2);
+    fail_unless (thread != NULL);
+
+    tmp = gst_gl_display_get_gl_context_for_thread (display, thread);
+    fail_unless (tmp == c2);
+    g_thread_unref (thread);
+    gst_object_unref (tmp);
+
+    /* undefined which context will be returned for the NULL thread */
+    tmp = gst_gl_display_get_gl_context_for_thread (display, NULL);
+    fail_unless (tmp != NULL);
+    gst_object_unref (tmp);
+  }
+
+  gst_object_unref (c1);
+  /* c1 is now dead */
+
+  {
+    GstGLContext *tmp;
+
+    tmp = gst_gl_display_get_gl_context_for_thread (display, NULL);
+    fail_unless (tmp == c2);
+    gst_object_unref (tmp);
+  }
+  GST_OBJECT_UNLOCK (display);
+
+  gst_object_unref (c2);
+  /* c2 is now dead */
+
+  {
+    /* no more contexts alive */
+    GstGLContext *tmp =
+        gst_gl_display_get_gl_context_for_thread (display, NULL);
+    fail_unless (tmp == NULL);
+  }
+}
+
+GST_END_TEST;
+
 static Suite *
 gst_gl_context_suite (void)
 {
@@ -530,6 +621,7 @@ gst_gl_context_suite (void)
   tcase_add_test (tc_chain, test_current_context);
   tcase_add_test (tc_chain, test_context_can_share);
   tcase_add_test (tc_chain, test_is_shared);
+  tcase_add_test (tc_chain, test_display_list);
 
   return s;
 }