The sensor and joystick instance ID generator isn't guarded by a lock.

src/joystick/SDL_joystick.c

@@ -116,7 +116,7 @@ static SDL_bool SDL_joysticks_initialized;
 static SDL_bool SDL_joysticks_quitting;
 static SDL_bool SDL_joystick_being_added;
 static SDL_Joystick *SDL_joysticks SDL_GUARDED_BY(SDL_joystick_lock) = NULL;
-static SDL_AtomicInt SDL_last_joystick_instance_id SDL_GUARDED_BY(SDL_joystick_lock);
+static SDL_AtomicInt SDL_last_joystick_instance_id;
 static int SDL_joystick_player_count SDL_GUARDED_BY(SDL_joystick_lock) = 0;
 static SDL_JoystickID *SDL_joystick_players SDL_GUARDED_BY(SDL_joystick_lock) = NULL;
 static SDL_bool SDL_joystick_allows_background_events = SDL_FALSE;

src/sensor/SDL_sensor.c

@@ -58,7 +58,7 @@ static SDL_AtomicInt SDL_sensor_lock_pending;
 static int SDL_sensors_locked;
 static SDL_bool SDL_sensors_initialized;
 static SDL_Sensor *SDL_sensors SDL_GUARDED_BY(SDL_sensor_lock) = NULL;
-static SDL_AtomicInt SDL_last_sensor_instance_id SDL_GUARDED_BY(SDL_sensor_lock);
+static SDL_AtomicInt SDL_last_sensor_instance_id;
 static char SDL_sensor_magic;
 
 #define CHECK_SENSOR_MAGIC(sensor, retval)              \