Add private utils module with a MutexGuard around GMutex

gstreamer/src/lib.rs

@@ -174,3 +174,5 @@ pub mod prelude {
     pub use tags::Tag;
     pub use miniobject::MiniObject;
 }
+
+mod utils;

gstreamer/src/utils.rs

@@ -0,0 +1,29 @@
+// Copyright (C) 2017 Sebastian Dröge <sebastian@centricular.com>
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use glib::translate::mut_override;
+use glib_ffi;
+
+pub struct MutexGuard<'a>(&'a glib_ffi::GMutex);
+
+impl<'a> MutexGuard<'a> {
+    pub fn lock(mutex: &'a glib_ffi::GMutex) -> Self {
+        unsafe {
+            glib_ffi::g_mutex_lock(mut_override(mutex));
+        }
+        MutexGuard(mutex)
+    }
+}
+
+impl<'a> Drop for MutexGuard<'a> {
+    fn drop(&mut self) {
+        unsafe {
+            glib_ffi::g_mutex_unlock(mut_override(self.0));
+        }
+    }
+}