From b21f5764309f9f65666016a9069e1b938935e6f2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Fri, 28 Feb 2020 16:29:48 +0200
Subject: [PATCH] Add #[must_use] attribute to mutex guards / stream lock

It's usually a mistake if creating one of these and immediately dropping
them again as that would immediately unlock the mutex again.
---
 gstreamer-base/src/utils.rs | 1 +
 gstreamer/src/pad.rs        | 1 +
 gstreamer/src/utils.rs      | 1 +
 3 files changed, 3 insertions(+)

diff --git a/gstreamer-base/src/utils.rs b/gstreamer-base/src/utils.rs
index dca8cf691..ff456cd06 100644
--- a/gstreamer-base/src/utils.rs
+++ b/gstreamer-base/src/utils.rs
@@ -9,6 +9,7 @@
 use glib::translate::mut_override;
 use glib_sys;
 
+#[must_use = "if unused the Mutex will immediately unlock"]
 pub struct MutexGuard<'a>(&'a glib_sys::GMutex);
 
 impl<'a> MutexGuard<'a> {
diff --git a/gstreamer/src/pad.rs b/gstreamer/src/pad.rs
index ee1118045..1b7062a38 100644
--- a/gstreamer/src/pad.rs
+++ b/gstreamer/src/pad.rs
@@ -104,6 +104,7 @@ unsafe impl<'a> Send for PadProbeData<'a> {}
 unsafe impl<'a> Sync for PadProbeData<'a> {}
 
 #[derive(Debug)]
+#[must_use = "if unused the StreamLock will immediately unlock"]
 pub struct StreamLock(Pad);
 impl Drop for StreamLock {
     fn drop(&mut self) {
diff --git a/gstreamer/src/utils.rs b/gstreamer/src/utils.rs
index dca8cf691..ff456cd06 100644
--- a/gstreamer/src/utils.rs
+++ b/gstreamer/src/utils.rs
@@ -9,6 +9,7 @@
 use glib::translate::mut_override;
 use glib_sys;
 
+#[must_use = "if unused the Mutex will immediately unlock"]
 pub struct MutexGuard<'a>(&'a glib_sys::GMutex);
 
 impl<'a> MutexGuard<'a> {