Implement set_notification_runloop

src/backend/mod.rs

@@ -217,6 +217,24 @@ impl Into<ChannelLayout> for CAChannelLabel {
     }
 }
 
+fn set_notification_runloop() {
+    let address = AudioObjectPropertyAddress {
+        mSelector: kAudioHardwarePropertyRunLoop,
+        mScope: kAudioObjectPropertyScopeGlobal,
+        mElement: kAudioObjectPropertyElementMaster,
+    };
+
+    // Ask HAL to manage its own thread for notification by setting the run_loop to NULL.
+    // Otherwise HAL may use main thread to fire notifications.
+    let run_loop: CFRunLoopRef = ptr::null_mut();
+    let size = mem::size_of::<CFRunLoopRef>();
+    let status =
+        audio_object_set_property_data(kAudioObjectSystemObject, &address, size, &run_loop);
+    if status != NO_ERR {
+        cubeb_log!("Could not make global CoreAudio notifications use their own thread.");
+    }
+}
+
 fn audiounit_make_silent(io_data: &mut AudioBuffer) {
     assert!(!io_data.mData.is_null());
     let bytes = unsafe {
@@ -2243,6 +2261,7 @@ impl AudioUnitContext {
 
 impl ContextOps for AudioUnitContext {
     fn init(_context_name: Option<&CStr>) -> Result<Context> {
+        set_notification_runloop();
         let mut ctx = Box::new(AudioUnitContext::new());
         ctx.init();
         Ok(unsafe { Context::from_ptr(Box::into_raw(ctx) as *mut _) })