gattlib_adapter_close: Do not block mutex while waiting for scan_loop…

…_thread to complete

dbus/gattlib_adapter.c

@@ -699,7 +699,16 @@ int gattlib_adapter_close(gattlib_adapter_t* adapter) {
 		gattlib_adapter_scan_disable(adapter);
 
 		_wait_scan_loop_stop_scanning(adapter);
+
+		// We must release gattlib mutex to not block the library
+		// We must also increase reference counter to not wait for a thread that has been freed
+		GThread *scan_loop_thread = adapter->backend.ble_scan.scan_loop_thread;
+		g_thread_ref(scan_loop_thread);
+		g_rec_mutex_unlock(&m_gattlib_mutex);
 		g_thread_join(adapter->backend.ble_scan.scan_loop_thread);
+		// At this stage scan_loop_thread should have completed
+		g_rec_mutex_lock(&m_gattlib_mutex);
+		g_thread_unref(scan_loop_thread);
 	}
 
 	// Unref/Free the adapter