ao_wasapi_changenotify: fix potential race condition

IMMDeviceEnumerator_RegisterEndpointNotificationCallback() will start
listening for notifications, and is the point at which callbacks can
start firing. These callbacks will read the fields we set after the
register calls, which is a potential race condition. Move it upwards.

1 files changed, 8 insertions, 8 deletions

diff --git a/audio/out/ao_wasapi_changenotify.c b/audio/out/ao_wasapi_changenotify.c
index b9806e0adb..dc529b638d 100644
--- a/audio/out/ao_wasapi_changenotify.c
+++ b/audio/out/ao_wasapi_changenotify.c
@@ -202,14 +202,6 @@ HRESULT wasapi_change_init(struct ao *ao, bool is_hotplug)
                                   (void **)&change->pEnumerator);
     EXIT_ON_ERROR(hr);
 
-    // COM voodoo to emulate c++ class
-    change->client.lpVtbl = &sIMMNotificationClientVtbl;
-
-    // register the change notification client
-    hr = IMMDeviceEnumerator_RegisterEndpointNotificationCallback(
-        change->pEnumerator, (IMMNotificationClient *)change);
-    EXIT_ON_ERROR(hr);
-
     // so the callbacks can access the ao
     change->ao = ao;
 
@@ -224,6 +216,14 @@ HRESULT wasapi_change_init(struct ao *ao, bool is_hotplug)
         MP_VERBOSE(ao, "Monitoring changes in device %S\n", change->monitored);
     }
 
+    // COM voodoo to emulate c++ class
+    change->client.lpVtbl = &sIMMNotificationClientVtbl;
+
+    // register the change notification client
+    hr = IMMDeviceEnumerator_RegisterEndpointNotificationCallback(
+        change->pEnumerator, (IMMNotificationClient *)change);
+    EXIT_ON_ERROR(hr);
+
     return hr;
 exit_label:
     MP_ERR(state, "Error setting up device change monitoring: %s\n",