From b7a52b0da0a1064fe659c23cda247f3e355f589c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Thu, 5 Jan 2023 16:39:56 +0200
Subject: [PATCH] gstreamer-app: Assert that GStreamer is initialized before
 creating instances

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1193>
---
 gstreamer-app/src/app_sink.rs |  1 +
 gstreamer-app/src/app_src.rs  |  1 +
 gstreamer-app/src/lib.rs      | 13 +++++++++++++
 3 files changed, 15 insertions(+)

diff --git a/gstreamer-app/src/app_sink.rs b/gstreamer-app/src/app_sink.rs
index be1dea64b..c00e42c32 100644
--- a/gstreamer-app/src/app_sink.rs
+++ b/gstreamer-app/src/app_sink.rs
@@ -273,6 +273,7 @@ impl AppSink {
     ///
     /// This method returns an instance of [`AppSinkBuilder`](crate::builders::AppSinkBuilder) which can be used to create [`AppSink`] objects.
     pub fn builder() -> AppSinkBuilder {
+        assert_initialized_main_thread!();
         AppSinkBuilder::default()
     }
 
diff --git a/gstreamer-app/src/app_src.rs b/gstreamer-app/src/app_src.rs
index 7169a5eca..fb366714d 100644
--- a/gstreamer-app/src/app_src.rs
+++ b/gstreamer-app/src/app_src.rs
@@ -210,6 +210,7 @@ impl AppSrc {
     ///
     /// This method returns an instance of [`AppSrcBuilder`](crate::builders::AppSrcBuilder) which can be used to create [`AppSrc`] objects.
     pub fn builder() -> AppSrcBuilder {
+        assert_initialized_main_thread!();
         AppSrcBuilder::default()
     }
 
diff --git a/gstreamer-app/src/lib.rs b/gstreamer-app/src/lib.rs
index 1d8bfc167..52bf150e4 100644
--- a/gstreamer-app/src/lib.rs
+++ b/gstreamer-app/src/lib.rs
@@ -10,6 +10,19 @@ pub use glib;
 pub use gst;
 pub use gst_base;
 
+macro_rules! assert_initialized_main_thread {
+    () => {
+        if !gst::INITIALIZED.load(std::sync::atomic::Ordering::SeqCst) {
+            #[allow(unused_unsafe)]
+            if unsafe { gst::ffi::gst_is_initialized() } != glib::ffi::GTRUE {
+                panic!("GStreamer has not been initialized. Call `gst::init` first.");
+            } else {
+                gst::INITIALIZED.store(true, std::sync::atomic::Ordering::SeqCst);
+            }
+        }
+    };
+}
+
 macro_rules! skip_assert_initialized {
     () => {};
 }