macos: Remove old NSApp workaround related code

This is no longer needed since the introduction of `gst_macos_main()` in 1.22.
Before that existed, we had a patch for GLib in Cerbero, which did work but made it
impossible to update GLib at all. The code being removed was a fail-safe in case of
running without said patch being applied. It's no longer needed, since for macOS
we just wrap our GStreamer with an NSApplication using `gst_macos_main()`.

Warnings will be displayed if no NSApp/NSRunLoop is found wherever needed,
pointing the user towards using the new API.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4366>

6 files changed, 15 insertions, 531 deletions

diff --git a/subprojects/gst-plugins-bad/gst-libs/gst/vulkan/cocoa/gstvkdisplay_cocoa.m b/subprojects/gst-plugins-bad/gst-libs/gst/vulkan/cocoa/gstvkdisplay_cocoa.m
index 6daa53db5f..0c35b59ec7 100644
--- a/subprojects/gst-plugins-bad/gst-libs/gst/vulkan/cocoa/gstvkdisplay_cocoa.m
+++ b/subprojects/gst-plugins-bad/gst-libs/gst/vulkan/cocoa/gstvkdisplay_cocoa.m
@@ -36,149 +36,8 @@ G_DEFINE_TYPE (GstVulkanDisplayCocoa, gst_vulkan_display_cocoa,
 static void gst_vulkan_display_cocoa_finalize (GObject * object);
 static gpointer gst_vulkan_display_cocoa_get_handle (GstVulkanDisplay * display);
 
-/* Define this if the GLib patch from
- * https://bugzilla.gnome.org/show_bug.cgi?id=741450
- * is used
- */
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-
-static GstVulkanDisplayCocoa *singleton = NULL;
-static gint nsapp_source_id = 0;
-static GMutex nsapp_lock;
-static GCond nsapp_cond;
-
-static gboolean
-gst_vulkan_display_cocoa_nsapp_iteration (gpointer data)
-{
-  NSEvent *event = nil;
-
-  if (![NSThread isMainThread]) {
-    GST_WARNING ("NSApp iteration not running in the main thread");
-    return FALSE;
-  }
-
-  while ((event = ([NSApp nextEventMatchingMask:NSEventMaskAny
-      untilDate:[NSDate dateWithTimeIntervalSinceNow:0.05]
-      inMode:NSDefaultRunLoopMode dequeue:YES])) != nil) {
-    [NSApp sendEvent:event];
-  }
-
-  return TRUE;
-}
 
 static void
-gst_vulkan_display_cocoa_open_and_attach_source (gpointer data)
-{
-  if ([NSThread isMainThread]) {
-    /* The sharedApplication class method initializes
-     * the display environment and connects your program
-     * to the window server and the display server.
-     * It has to be done in the main thread.
-     */
-    [NSApplication sharedApplication];
-
-    GST_DEBUG ("Custom NSApp initialization done");
-
-    nsapp_source_id = g_timeout_add (60, gst_vulkan_display_cocoa_nsapp_iteration,
-        NULL);
-
-    GST_DEBUG ("NSApp iteration loop attached, id %d", nsapp_source_id);
-  }
-}
-
-static gboolean
-gst_vulkan_display_cocoa_init_nsapp (gpointer data)
-{
-  g_mutex_lock (&nsapp_lock);
-
-  gst_vulkan_display_cocoa_open_and_attach_source (data);
-
-  g_cond_signal (&nsapp_cond);
-  g_mutex_unlock (&nsapp_lock);
-
-  return FALSE;
-}
-
-static GstVulkanDisplayCocoa *
-gst_vulkan_display_cocoa_setup_nsapp (gpointer data)
-{
-  GMainContext *context = g_main_context_default ();
-  gint delta_ms = 0;
-
-  g_mutex_lock (&nsapp_lock);
-
-  if (singleton) {
-    GST_DEBUG ("Get existing display");
-    singleton = gst_object_ref (singleton);
-    g_mutex_unlock (&nsapp_lock);
-    return singleton;
-  }
-
-  if (NSApp != nil && !singleton) {
-    GstVulkanDisplayCocoa *ret = g_object_new (GST_TYPE_VULKAN_DISPLAY_COCOA, NULL);
-    gst_object_ref_sink (ret);
-    g_mutex_unlock (&nsapp_lock);
-    return ret;
-  }
-
-  /* All application have to start with [NSApplication sharedApplication]
-   * so if NSApp is nil here let's assume this is a debugging application
-   * that runs a glib main loop. */
-  g_assert (NSApp == nil);
-
-  GST_DEBUG ("The application has not initialized NSApp");
-
-  if ([NSThread isMainThread]) {
-
-    GST_DEBUG ("Setting up NSApp from the main thread");
-    if (g_main_context_is_owner (context)) {
-      GST_DEBUG ("The main thread own the context");
-      gst_vulkan_display_cocoa_open_and_attach_source (data);
-    } else if (g_main_context_acquire (context)) {
-      GST_DEBUG ("The main loop should be shortly running in the main thread");
-      gst_vulkan_display_cocoa_open_and_attach_source (data);
-      g_main_context_release (context);
-    } else {
-      GST_WARNING ("Main loop running in another thread");
-    }
-  } else {
-
-    GST_DEBUG ("Setting up NSApp not from the main thread");
-
-    if (g_main_context_is_owner (context)) {
-      GST_WARNING ("Default context not own by the main thread");
-      delta_ms = -1;
-    } else if (g_main_context_acquire (context)) {
-      GST_DEBUG ("The main loop should be shortly running in the main thread");
-      delta_ms = 1000;
-      g_main_context_release (context);
-    } else {
-      GST_DEBUG ("Main loop running in main thread");
-      delta_ms = 500;
-    }
-
-    if (delta_ms > 0) {
-      gint64 end_time = g_get_monotonic_time () + delta_ms * 1000;;
-      g_idle_add_full (G_PRIORITY_HIGH, gst_vulkan_display_cocoa_init_nsapp, data, NULL);
-      g_cond_wait_until (&nsapp_cond, &nsapp_lock, end_time);
-    }
-  }
-
-  if (NSApp == nil) {
-    GST_ERROR ("Custom NSApp initialization failed");
-  } else {
-    GST_DEBUG ("Create display");
-    singleton = g_object_new (GST_TYPE_VULKAN_DISPLAY_COCOA, NULL);
-    gst_object_ref_sink (singleton);
-  }
-
-  g_mutex_unlock (&nsapp_lock);
-
-  return singleton;
-}
-
-#endif
-static void
 gst_vulkan_display_cocoa_class_init (GstVulkanDisplayCocoaClass * klass)
 {
   GST_VULKAN_DISPLAY_CLASS (klass)->get_handle =
@@ -198,21 +57,6 @@ gst_vulkan_display_cocoa_init (GstVulkanDisplayCocoa * display_cocoa)
 static void
 gst_vulkan_display_cocoa_finalize (GObject * object)
 {
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-  g_mutex_lock (&nsapp_lock);
-  if (singleton) {
-    GST_DEBUG ("Destroy display");
-    singleton = NULL;
-    if (nsapp_source_id) {
-      GST_DEBUG ("Remove NSApp loop iteration, id %d", nsapp_source_id);
-      g_source_remove (nsapp_source_id);
-    }
-    nsapp_source_id = 0;
-    g_mutex_unlock (&nsapp_lock);
-  }
-  g_mutex_unlock (&nsapp_lock);
-#endif
-
   G_OBJECT_CLASS (gst_vulkan_display_cocoa_parent_class)->finalize (object);
 }
 
@@ -230,12 +74,13 @@ gst_vulkan_display_cocoa_new (void)
 
   GST_DEBUG_CATEGORY_GET (gst_vulkan_display_debug, "vulkandisplay");
 
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-  ret = gst_vulkan_display_cocoa_setup_nsapp (NULL);
-#else
+  if (NSApp == nil)
+    g_warning ("An NSApplication needs to be running on the main thread "
+        "to ensure correct behaviour on macOS. Use gst_macos_main() or call "
+        "[NSApplication sharedApplication] in your code before using this element.");
+
   ret = g_object_new (GST_TYPE_VULKAN_DISPLAY_COCOA, NULL);
   gst_object_ref_sink (ret);
-#endif
 
   return ret;
 }
diff --git a/subprojects/gst-plugins-base/gst-libs/gst/gl/cocoa/gstgldisplay_cocoa.m b/subprojects/gst-plugins-base/gst-libs/gst/gl/cocoa/gstgldisplay_cocoa.m
index cf9ad2b721..10f3b53786 100644
--- a/subprojects/gst-plugins-base/gst-libs/gst/gl/cocoa/gstgldisplay_cocoa.m
+++ b/subprojects/gst-plugins-base/gst-libs/gst/gl/cocoa/gstgldisplay_cocoa.m
@@ -35,164 +35,17 @@ GST_DEBUG_CATEGORY_STATIC (gst_gl_display_debug);
 
 G_DEFINE_TYPE (GstGLDisplayCocoa, gst_gl_display_cocoa, GST_TYPE_GL_DISPLAY);
 
-static void gst_gl_display_cocoa_finalize (GObject * object);
 static guintptr gst_gl_display_cocoa_get_handle (GstGLDisplay * display);
 
 #if MAC_OS_X_VERSION_MAX_ALLOWED < 101200
 #define NSEventMaskAny                       NSAnyEventMask
 #endif
 
-/* Define this if the GLib patch from
- * https://bugzilla.gnome.org/show_bug.cgi?id=741450
- * is used
- */
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-
-static GstGLDisplayCocoa *singleton = NULL;
-static gint nsapp_source_id = 0;
-static GMutex nsapp_lock;
-static GCond nsapp_cond;
-
-static gboolean
-gst_gl_display_cocoa_nsapp_iteration (gpointer data)
-{
-  NSEvent *event = nil;
-
-  if (![NSThread isMainThread]) {
-    GST_WARNING ("NSApp iteration not running in the main thread");
-    return FALSE;
-  }
-
-
-  while ((event = ([NSApp nextEventMatchingMask:NSEventMaskAny
-      untilDate:[NSDate dateWithTimeIntervalSinceNow:0.05]
-      inMode:NSDefaultRunLoopMode dequeue:YES])) != nil) {
-    [NSApp sendEvent:event];
-  }
-
-  return TRUE;
-}
-
-static void
-gst_gl_display_cocoa_open_and_attach_source (gpointer data)
-{
-  if ([NSThread isMainThread]) {
-    /* The sharedApplication class method initializes
-     * the display environment and connects your program
-     * to the window server and the display server.
-     * It has to be done in the main thread.
-     */
-    [NSApplication sharedApplication];
-
-    GST_DEBUG ("Custom NSApp initialization done");
-
-    nsapp_source_id = g_timeout_add (60, gst_gl_display_cocoa_nsapp_iteration,
-        NULL);
-
-    GST_DEBUG ("NSApp iteration loop attached, id %d", nsapp_source_id);
-  }
-}
-
-static gboolean
-gst_gl_display_cocoa_init_nsapp (gpointer data)
-{
-  g_mutex_lock (&nsapp_lock);
-
-  gst_gl_display_cocoa_open_and_attach_source (data);
-
-  g_cond_signal (&nsapp_cond);
-  g_mutex_unlock (&nsapp_lock);
-
-  return FALSE;
-}
-
-static GstGLDisplayCocoa *
-gst_gl_display_cocoa_setup_nsapp (gpointer data)
-{
-  GMainContext *context = g_main_context_default ();
-  gint delta_ms = 0;
-
-  g_mutex_lock (&nsapp_lock);
-
-  if (singleton) {
-    GST_DEBUG ("Get existing display");
-    singleton = gst_object_ref (singleton);
-    g_mutex_unlock (&nsapp_lock);
-    return singleton;
-  }
-
-  if (NSApp != nil && !singleton) {
-    GstGLDisplayCocoa *ret = g_object_new (GST_TYPE_GL_DISPLAY_COCOA, NULL);
-    gst_object_ref_sink (ret);
-    g_mutex_unlock (&nsapp_lock);
-    return ret;
-  }
-
-  /* All application have to start with [NSApplication sharedApplication]
-   * so if NSApp is nil here let's assume this is a debugging application
-   * that runs a glib main loop. */
-  g_assert (NSApp == nil);
-
-  GST_DEBUG ("The application has not initialized NSApp");
-
-  if ([NSThread isMainThread]) {
-
-    GST_DEBUG ("Setting up NSApp from the main thread");
-    if (g_main_context_is_owner (context)) {
-      GST_DEBUG ("The main thread own the context");
-      gst_gl_display_cocoa_open_and_attach_source (data);
-    } else if (g_main_context_acquire (context)) {
-      GST_DEBUG ("The main loop should be shortly running in the main thread");
-      gst_gl_display_cocoa_open_and_attach_source (data);
-      g_main_context_release (context);
-    } else {
-      GST_WARNING ("Main loop running in another thread");
-    }
-  } else {
-
-    GST_DEBUG ("Setting up NSApp not from the main thread");
-
-    if (g_main_context_is_owner (context)) {
-      GST_WARNING ("Default context not own by the main thread");
-      delta_ms = -1;
-    } else if (g_main_context_acquire (context)) {
-      GST_DEBUG ("The main loop should be shortly running in the main thread");
-      delta_ms = 1000;
-      g_main_context_release (context);
-    } else {
-      GST_DEBUG ("Main loop running in main thread");
-      delta_ms = 500;
-    }
-
-    if (delta_ms > 0) {
-      gint64 end_time = g_get_monotonic_time () + delta_ms * 1000;;
-      g_idle_add_full (G_PRIORITY_HIGH, gst_gl_display_cocoa_init_nsapp, data, NULL);
-      g_cond_wait_until (&nsapp_cond, &nsapp_lock, end_time);
-    }
-  }
-
-  if (NSApp == nil) {
-    GST_ERROR ("Custom NSApp initialization failed");
-  } else {
-    GST_DEBUG ("Create display");
-    singleton = g_object_new (GST_TYPE_GL_DISPLAY_COCOA, NULL);
-    gst_object_ref_sink (singleton);
-  }
-
-  g_mutex_unlock (&nsapp_lock);
-
-  return singleton;
-}
-
-#endif
-
 static void
 gst_gl_display_cocoa_class_init (GstGLDisplayCocoaClass * klass)
 {
   GST_GL_DISPLAY_CLASS (klass)->get_handle =
       GST_DEBUG_FUNCPTR (gst_gl_display_cocoa_get_handle);
-
-  G_OBJECT_CLASS (klass)->finalize = gst_gl_display_cocoa_finalize;
 }
 
 static void
@@ -202,27 +55,6 @@ gst_gl_display_cocoa_init (GstGLDisplayCocoa * display_cocoa)
   display->type = GST_GL_DISPLAY_TYPE_COCOA;
 }
 
-static void
-gst_gl_display_cocoa_finalize (GObject * object)
-{
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-  g_mutex_lock (&nsapp_lock);
-  if (singleton) {
-    GST_DEBUG ("Destroy display");
-    singleton = NULL;
-    if (nsapp_source_id) {
-      GST_DEBUG ("Remove NSApp loop iteration, id %d", nsapp_source_id);
-      g_source_remove (nsapp_source_id);
-    }
-    nsapp_source_id = 0;
-    g_mutex_unlock (&nsapp_lock);
-  }
-  g_mutex_unlock (&nsapp_lock);
-#endif
-
-  G_OBJECT_CLASS (gst_gl_display_cocoa_parent_class)->finalize (object);
-}
-
 /**
  * gst_gl_display_cocoa_new:
  *
@@ -237,12 +69,13 @@ gst_gl_display_cocoa_new (void)
 
   GST_DEBUG_CATEGORY_GET (gst_gl_display_debug, "gldisplay");
 
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-  display = gst_gl_display_cocoa_setup_nsapp (NULL);
-#else
+  if (NSApp == nil)
+    g_warning ("An NSApplication needs to be running on the main thread "
+        "to ensure correct behaviour on macOS. Use gst_macos_main() or call "
+        "[NSApplication sharedApplication] in your code before using this element.");
+
   display = g_object_new (GST_TYPE_GL_DISPLAY_COCOA, NULL);
   gst_object_ref_sink (display);
-#endif
 
   return display;
 }
diff --git a/subprojects/gst-plugins-good/sys/osxvideo/cocoawindow.h b/subprojects/gst-plugins-good/sys/osxvideo/cocoawindow.h
index 816f1bbd2d..756676cdf2 100644
--- a/subprojects/gst-plugins-good/sys/osxvideo/cocoawindow.h
+++ b/subprojects/gst-plugins-good/sys/osxvideo/cocoawindow.h
@@ -69,9 +69,6 @@ struct _GstOSXImage;
 - (void) addToSuperview: (NSView *)superview;
 - (void) removeFromSuperview: (id)unused;
 - (void) setNavigation: (GstNavigation *) nav;
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-- (void) setMainThread: (NSThread *) thread;
-#endif
 
 @end
 
diff --git a/subprojects/gst-plugins-good/sys/osxvideo/cocoawindow.m b/subprojects/gst-plugins-good/sys/osxvideo/cocoawindow.m
index ef2b0c61af..611652522e 100644
--- a/subprojects/gst-plugins-good/sys/osxvideo/cocoawindow.m
+++ b/subprojects/gst-plugins-good/sys/osxvideo/cocoawindow.m
@@ -667,12 +667,6 @@ const gchar* gst_keycode_to_keyname(gint16 keycode)
   [self reshape];
 }
 
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-- (void) setMainThread: (NSThread *) thread {
-  mainThread = thread;
-}
-#endif
-
 - (void) haveSuperviewReal:(NSMutableArray *)closure {
 	BOOL haveSuperview = [self superview] != nil;
 	[closure addObject:[NSNumber numberWithBool:haveSuperview]];
diff --git a/subprojects/gst-plugins-good/sys/osxvideo/osxvideosink.h b/subprojects/gst-plugins-good/sys/osxvideo/osxvideosink.h
index d467b0e464..da4c079e59 100644
--- a/subprojects/gst-plugins-good/sys/osxvideo/osxvideosink.h
+++ b/subprojects/gst-plugins-good/sys/osxvideo/osxvideosink.h
@@ -128,11 +128,6 @@ GType gst_osx_video_sink_get_type(void);
 -(void) destroy;
 -(void) showFrame: (GstBufferObject*) buf;
 -(void) setView: (NSView*) view;
-+ (BOOL) isMainThread;
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
--(void) nsAppThread;
--(void) checkMainRunLoop;
-#endif
 @end
 
 G_END_DECLS
diff --git a/subprojects/gst-plugins-good/sys/osxvideo/osxvideosink.m b/subprojects/gst-plugins-good/sys/osxvideo/osxvideosink.m
index 4d5d2b4551..1669b961a3 100644
--- a/subprojects/gst-plugins-good/sys/osxvideo/osxvideosink.m
+++ b/subprojects/gst-plugins-good/sys/osxvideo/osxvideosink.m
@@ -43,12 +43,6 @@
 GST_DEBUG_CATEGORY (gst_debug_osx_video_sink);
 #define GST_CAT_DEFAULT gst_debug_osx_video_sink
 
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-#include <pthread.h>
-extern void _CFRunLoopSetCurrent (CFRunLoopRef rl);
-extern pthread_t _CFMainPThread;
-#endif
-
 static GstStaticPadTemplate gst_osx_video_sink_sink_template_factory =
 GST_STATIC_PAD_TEMPLATE ("sink",
     GST_PAD_SINK,
@@ -73,12 +67,6 @@ enum
 
 static void gst_osx_video_sink_osxwindow_destroy (GstOSXVideoSink * osxvideosink);
 
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-static GMutex _run_loop_check_mutex;
-static GMutex _run_loop_mutex;
-static GCond _run_loop_cond;
-#endif
-
 static GstOSXVideoSinkClass *sink_class = NULL;
 static GstVideoSinkClass *parent_class = NULL;
 
@@ -111,126 +99,6 @@ gst_osx_video_sink_call_from_main_thread(GstOSXVideoSink *osxvideosink,
   [pool release];
 }
 
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-/* Poll for cocoa events */
-static void
-run_ns_app_loop (void) {
-  NSEvent *event;
-  NSAutoreleasePool *pool =[[NSAutoreleasePool alloc] init];
-  NSDate *pollTime = nil;
-
-  /* when running the loop in a thread we want to sleep as long as possible */
-  pollTime = [NSDate distantFuture];
-
-  do {
-      event = [NSApp nextEventMatchingMask:NSEventMaskAny untilDate:pollTime
-          inMode:NSDefaultRunLoopMode dequeue:YES];
-      [NSApp sendEvent:event];
-    }
-  while (event != nil);
-  [pool release];
-}
-
-static void
-gst_osx_videosink_check_main_run_loop (GstOSXVideoSink *sink)
-{
-  /* check if the main run loop is running */
-  gboolean is_running;
-
-  /* the easy way */
-  is_running = [[NSRunLoop mainRunLoop] currentMode] != nil;
-  if (is_running) {
-    goto exit;
-  } else {
-    /* the previous check doesn't always work with main loops that run
-     * cocoa's main run loop manually, like the gdk one, giving false
-     * negatives. This check defers a call to the main thread and waits to
-     * be awaken by this function. */
-    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
-    GstOSXVideoSinkObject * object = (GstOSXVideoSinkObject *) sink->osxvideosinkobject;
-    gint64 abstime;
-
-    g_mutex_lock (&_run_loop_mutex);
-    [object performSelectorOnMainThread:
-          @selector(checkMainRunLoop)
-          withObject:nil waitUntilDone:NO];
-    /* Wait 100 ms */
-    abstime = g_get_monotonic_time () + 100 * 1000;
-    is_running = g_cond_wait_until (&_run_loop_cond,
-        &_run_loop_mutex, abstime);
-    g_mutex_unlock (&_run_loop_mutex);
-
-    [pool release];
-  }
-
-exit:
-  {
-  GST_DEBUG_OBJECT(sink, "The main runloop %s is running",
-      is_running ? "" : " not ");
-  if (is_running) {
-    sink_class->run_loop_state = GST_OSX_VIDEO_SINK_RUN_LOOP_STATE_RUNNING;
-    sink_class->ns_app_thread = [NSThread mainThread];
-  } else {
-    sink_class->run_loop_state = GST_OSX_VIDEO_SINK_RUN_LOOP_STATE_NOT_RUNNING;
-  }
-  }
-}
-
-static void
-gst_osx_video_sink_run_cocoa_loop (GstOSXVideoSink * sink )
-{
-  /* Cocoa applications require a main runloop running to dispatch UI
-   * events and process deferred calls to the main thread through
-   * perfermSelectorOnMainThread.
-   * Since the sink needs to create it's own Cocoa window when no
-   * external NSView is passed to the sink through the GstVideoOverlay API,
-   * we need to run the cocoa mainloop somehow.
-   * This run loop can only be started once, by the first sink needing it
-   */
-
-  g_mutex_lock (&_run_loop_check_mutex);
-
-  if (sink_class->run_loop_state == GST_OSX_VIDEO_SINK_RUN_LOOP_STATE_UNKNOWN) {
-    gst_osx_videosink_check_main_run_loop (sink);
-  }
-
-  if (sink_class->run_loop_state == GST_OSX_VIDEO_SINK_RUN_LOOP_STATE_RUNNING) {
-    g_mutex_unlock (&_run_loop_check_mutex);
-    return;
-  }
-
-  if (sink_class->ns_app_thread == NULL) {
-    /* run the main runloop in a separate thread */
-
-    /* override [NSThread isMainThread] with our own implementation so that we can
-     * make it believe our dedicated thread is the main thread
-     */
-    Method origIsMainThread = class_getClassMethod([NSThread class],
-        NSSelectorFromString(@"isMainThread"));
-    Method ourIsMainThread = class_getClassMethod([GstOSXVideoSinkObject class],
-        NSSelectorFromString(@"isMainThread"));
-
-    method_exchangeImplementations(origIsMainThread, ourIsMainThread);
-
-    sink_class->ns_app_thread = [[NSThread alloc]
-        initWithTarget:sink->osxvideosinkobject
-        selector:@selector(nsAppThread) object:nil];
-    [sink_class->ns_app_thread start];
-
-    g_mutex_lock (&_run_loop_mutex);
-    g_cond_wait (&_run_loop_cond, &_run_loop_mutex);
-    g_mutex_unlock (&_run_loop_mutex);
-  }
-
-  g_mutex_unlock (&_run_loop_check_mutex);
-}
-
-static void
-gst_osx_video_sink_stop_cocoa_loop (GstOSXVideoSink * osxvideosink)
-{
-}
-#endif
-
 /* This function handles osx window creation */
 static gboolean
 gst_osx_video_sink_osxwindow_create (GstOSXVideoSink * osxvideosink, gint width,
@@ -260,11 +128,6 @@ gst_osx_video_sink_osxwindow_create (GstOSXVideoSink * osxvideosink, gint width,
   rect.size.height = (float) osxwindow->height;
   osxwindow->gstview =[[GstGLView alloc] initWithFrame:rect];
 
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-  gst_osx_video_sink_run_cocoa_loop (osxvideosink);
-  [osxwindow->gstview setMainThread:sink_class->ns_app_thread];
-#endif
-
   if (osxvideosink->superview == NULL) {
     GST_INFO_OBJECT (osxvideosink, "emitting prepare-xwindow-id");
     gst_video_overlay_prepare_window_handle (GST_VIDEO_OVERLAY (osxvideosink));
@@ -304,9 +167,6 @@ gst_osx_video_sink_osxwindow_destroy (GstOSXVideoSink * osxvideosink)
   gst_osx_video_sink_call_from_main_thread(osxvideosink,
       osxvideosink->osxvideosinkobject,
       @selector(destroy), (id) nil, YES);
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
-  gst_osx_video_sink_stop_cocoa_loop (osxvideosink);
-#endif
   [pool release];
 }
 
@@ -512,6 +372,11 @@ gst_osx_video_sink_propose_allocation (GstBaseSink * base_sink, GstQuery * query
 static void
 gst_osx_video_sink_init (GstOSXVideoSink * sink)
 {
+  if ([[NSRunLoop mainRunLoop] currentMode] == nil)
+    g_warning ("An NSRunLoop needs to be running on the main thread "
+        "to ensure correct behaviour on macOS. Use gst_macos_main() or call "
+        "[NSApplication sharedApplication] in your code before using this element.");
+
   sink->osxwindow = NULL;
   sink->superview = NULL;
   sink->osxvideosinkobject = [[GstOSXVideoSinkObject alloc] initWithSink:sink];
@@ -794,12 +659,6 @@ gst_osx_video_sink_get_type (void)
 
 }
 
-+ (BOOL) isMainThread
-{
-  /* FIXME: ideally we should return YES only for ->ns_app_thread here */
-  return YES;
-}
-
 - (void) setView: (NSView*)view
 {
   NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
@@ -931,49 +790,10 @@ no_texture_buffer:
     g_free (osxwindow);
   }
   GST_OBJECT_UNLOCK (osxvideosink);
-  
-  [pool release];
-}
-
-#ifndef GSTREAMER_GLIB_COCOA_NSAPPLICATION
--(void) nsAppThread
-{
-  NSAutoreleasePool *pool;
-
-  /* set the main runloop as the runloop for the current thread. This has the
-   * effect that calling NSApp nextEventMatchingMask:untilDate:inMode:dequeue
-   * runs the main runloop.
-   */
-  _CFRunLoopSetCurrent(CFRunLoopGetMain());
-
-  /* this is needed to make IsMainThread checks in core foundation work from the
-   * current thread
-   */
-  _CFMainPThread = pthread_self();
-
-  pool = [[NSAutoreleasePool alloc] init];
-
-  [NSApplication sharedApplication];
-  [NSApp finishLaunching];
-
-  g_mutex_lock (&_run_loop_mutex);
-  g_cond_signal (&_run_loop_cond);
-  g_mutex_unlock (&_run_loop_mutex);
-
-  /* run the loop */
-  run_ns_app_loop ();
 
   [pool release];
 }
 
--(void) checkMainRunLoop
-{
-  g_mutex_lock (&_run_loop_mutex);
-  g_cond_signal (&_run_loop_cond);
-  g_mutex_unlock (&_run_loop_mutex);
-}
-#endif
-
 @end
 
 @ implementation GstBufferObject