Added a single source of SDL object IDs

This ensures that we don't accidentally interpret an ID from one system as an ID in another system.
Audio device IDs are not covered here, since they have a unique numbering system.

src/SDL.c

@@ -514,6 +514,20 @@ void SDL_Quit(void)
     SDL_bInMainQuit = SDL_FALSE;
 }
 
+/* Assume we can wrap SDL_AtomicInt values and cast to Uint32 */
+SDL_COMPILE_TIME_ASSERT(sizeof_object_id, sizeof(int) == sizeof(Uint32));
+
+Uint32 SDL_GetNextObjectID(void)
+{
+    static SDL_AtomicInt last_id;
+
+    Uint32 id = (Uint32)SDL_AtomicIncRef(&last_id) + 1;
+    if (id == 0) {
+        id = (Uint32)SDL_AtomicIncRef(&last_id) + 1;
+    }
+    return id;
+}
+
 /* Get the library version number */
 int SDL_GetVersion(SDL_version *ver)
 {

src/SDL_internal.h

@@ -197,6 +197,7 @@
 extern "C" {
 #endif
 
+extern DECLSPEC Uint32 SDLCALL SDL_GetNextObjectID(void);
 extern DECLSPEC int SDLCALL SDL_WaitSemaphoreTimeoutNS(SDL_Semaphore *sem, Sint64 timeoutNS);
 extern DECLSPEC int SDLCALL SDL_WaitConditionTimeoutNS(SDL_Condition *cond, SDL_Mutex *mutex, Sint64 timeoutNS);
 extern DECLSPEC int SDLCALL SDL_WaitEventTimeoutNS(SDL_Event *event, Sint64 timeoutNS);

src/joystick/SDL_joystick.c

@@ -116,7 +116,6 @@ 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;
 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;
@@ -413,15 +412,6 @@ SDL_JoystickID *SDL_GetJoysticks(int *count)
     return joysticks;
 }
 
-/*
- * Return the next available joystick instance ID
- * This may be called by drivers from multiple threads, unprotected by any locks
- */
-SDL_JoystickID SDL_GetNextJoystickInstanceID(void)
-{
-    return SDL_AtomicIncRef(&SDL_last_joystick_instance_id) + 1;
-}
-
 /*
  * Get the implementation dependent name of a joystick
  */

src/joystick/SDL_joystick_c.h

@@ -53,9 +53,6 @@ extern void SDL_AssertJoysticksLocked(void) SDL_ASSERT_CAPABILITY(SDL_joystick_l
 /* Function to return whether there are any joysticks opened by the application */
 extern SDL_bool SDL_JoysticksOpened(void);
 
-/* Function to get the next available joystick instance ID */
-extern SDL_JoystickID SDL_GetNextJoystickInstanceID(void);
-
 /* Function to standardize the name for a controller
    This should be freed with SDL_free() when no longer needed
  */

src/joystick/android/SDL_sysjoystick.c

@@ -378,7 +378,7 @@ int Android_AddJoystick(int device_id, const char *name, const char *desc, int v
     }
     item->naxes = naxes;
     item->nhats = nhats;
-    item->device_instance = SDL_GetNextJoystickInstanceID();
+    item->device_instance = SDL_GetNextObjectID();
     if (SDL_joylist_tail == NULL) {
         SDL_joylist = SDL_joylist_tail = item;
     } else {

src/joystick/apple/SDL_mfijoystick.m

@@ -561,7 +561,7 @@ static void IOS_AddJoystickDevice(GCController *controller, SDL_bool acceleromet
     }
 
     device->accelerometer = accelerometer;
-    device->instance_id = SDL_GetNextJoystickInstanceID();
+    device->instance_id = SDL_GetNextObjectID();
 
     if (accelerometer) {
 #ifdef SDL_JOYSTICK_iOS_ACCELEROMETER

src/joystick/bsd/SDL_bsdjoystick.c

@@ -466,7 +466,7 @@ static int MaybeAddDevice(const char *path)
         return -1;
     }
 
-    item->device_instance = SDL_GetNextJoystickInstanceID();
+    item->device_instance = SDL_GetNextObjectID();
     if (SDL_joylist_tail == NULL) {
         SDL_joylist = SDL_joylist_tail = item;
     } else {

src/joystick/darwin/SDL_iokitjoystick.c

@@ -549,7 +549,7 @@ static void JoystickDeviceWasAddedCallback(void *ctx, IOReturn res, void *sender
     device->runLoopAttached = SDL_TRUE;
 
     /* Allocate an instance ID for this device */
-    device->instance_id = SDL_GetNextJoystickInstanceID();
+    device->instance_id = SDL_GetNextObjectID();
 
     /* We have to do some storage of the io_service_t for SDL_HapticOpenFromJoystick */
     ioservice = IOHIDDeviceGetService(ioHIDDeviceObject);

src/joystick/hidapi/SDL_hidapijoystick.c

@@ -790,7 +790,7 @@ SDL_bool HIDAPI_JoystickConnected(SDL_HIDAPI_Device *device, SDL_JoystickID *pJo
         }
     }
 
-    joystickID = SDL_GetNextJoystickInstanceID();
+    joystickID = SDL_GetNextObjectID();
     HIDAPI_AddJoystickInstanceToDevice(device, joystickID);
 
     for (i = 0; i < device->num_children; ++i) {

src/joystick/linux/SDL_sysjoystick.c

@@ -443,7 +443,7 @@ static int MaybeAddDevice(const char *path)
             return -1;
         }
 
-        item->device_instance = SDL_GetNextJoystickInstanceID();
+        item->device_instance = SDL_GetNextObjectID();
         if (SDL_joylist_tail == NULL) {
             SDL_joylist = SDL_joylist_tail = item;
         } else {
@@ -615,7 +615,7 @@ static SDL_bool SteamControllerConnectedCallback(const char *name, SDL_JoystickG
         return SDL_FALSE;
     }
 
-    *device_instance = item->device_instance = SDL_GetNextJoystickInstanceID();
+    *device_instance = item->device_instance = SDL_GetNextObjectID();
     if (SDL_joylist_tail == NULL) {
         SDL_joylist = SDL_joylist_tail = item;
     } else {

src/joystick/virtual/SDL_virtualjoystick.c

@@ -237,7 +237,7 @@ SDL_JoystickID SDL_JoystickAttachVirtualInner(const SDL_VirtualJoystickDesc *des
     }
 
     /* Allocate an instance ID for this device */
-    hwdata->instance_id = SDL_GetNextJoystickInstanceID();
+    hwdata->instance_id = SDL_GetNextObjectID();
 
     /* Add virtual joystick to SDL-global lists */
     if (g_VJoys) {

src/joystick/windows/SDL_rawinputjoystick.c

@@ -920,7 +920,7 @@ static void RAWINPUT_AddDevice(HANDLE hDevice)
     CloseHandle(hFile);
     hFile = INVALID_HANDLE_VALUE;
 
-    device->joystick_id = SDL_GetNextJoystickInstanceID();
+    device->joystick_id = SDL_GetNextObjectID();
 
 #ifdef DEBUG_RAWINPUT
     SDL_Log("Adding RAWINPUT device '%s' VID 0x%.4x, PID 0x%.4x, version %d, handle 0x%.8x\n", device->name, device->vendor_id, device->product_id, device->version, device->hDevice);

src/joystick/windows/SDL_windows_gaming_input.c

@@ -489,7 +489,7 @@ static HRESULT STDMETHODCALLTYPE IEventHandler_CRawGameControllerVtbl_InvokeAdde
             WindowsGamingInputControllerState *controllers = SDL_realloc(wgi.controllers, sizeof(wgi.controllers[0]) * (wgi.controller_count + 1));
             if (controllers) {
                 WindowsGamingInputControllerState *state = &controllers[wgi.controller_count];
-                SDL_JoystickID joystickID = SDL_GetNextJoystickInstanceID();
+                SDL_JoystickID joystickID = SDL_GetNextObjectID();
 
                 SDL_zerop(state);
                 state->instance_id = joystickID;

src/joystick/windows/SDL_windowsjoystick.c

@@ -453,7 +453,7 @@ static void SDL_StopJoystickThread(void)
 void WINDOWS_AddJoystickDevice(JoyStick_DeviceData *device)
 {
     device->send_add_event = SDL_TRUE;
-    device->nInstanceID = SDL_GetNextJoystickInstanceID();
+    device->nInstanceID = SDL_GetNextObjectID();
     device->pNext = SYS_Joystick;
     SYS_Joystick = device;
 }

src/sensor/SDL_sensor.c

@@ -58,7 +58,6 @@ 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;
 static char SDL_sensor_magic;
 
 #define CHECK_SENSOR_MAGIC(sensor, retval)              \
@@ -218,15 +217,6 @@ SDL_SensorID *SDL_GetSensors(int *count)
     return sensors;
 }
 
-/*
- * Return the next available sensor instance ID
- * This may be called by drivers from multiple threads, unprotected by any locks
- */
-SDL_SensorID SDL_GetNextSensorInstanceID(void)
-{
-    return SDL_AtomicIncRef(&SDL_last_sensor_instance_id) + 1;
-}
-
 /*
  * Get the driver and device index for a sensor instance ID
  * This should be called while the sensor lock is held, to prevent another thread from updating the list

src/sensor/SDL_sensor_c.h

@@ -31,9 +31,6 @@ struct SDL_SensorDriver;
 
 /* Useful functions and variables from SDL_sensor.c */
 
-/* Function to get the next available sensor instance ID */
-extern SDL_SensorID SDL_GetNextSensorInstanceID(void);
-
 /* Initialization and shutdown functions */
 extern int SDL_InitSensors(void);
 extern void SDL_QuitSensors(void);

src/sensor/android/SDL_androidsensor.c

@@ -152,7 +152,7 @@ static int SDL_ANDROID_SensorInit(void)
 
         for (i = 0; i < sensors_count; ++i) {
             SDL_sensors[i].asensor = sensors[i];
-            SDL_sensors[i].instance_id = SDL_GetNextSensorInstanceID();
+            SDL_sensors[i].instance_id = SDL_GetNextObjectID();
         }
         SDL_sensors_count = sensors_count;
     }

src/sensor/coremotion/SDL_coremotionsensor.m

@@ -63,12 +63,12 @@ static int SDL_COREMOTION_SensorInit(void)
         i = 0;
         if (SDL_motion_manager.accelerometerAvailable) {
             SDL_sensors[i].type = SDL_SENSOR_ACCEL;
-            SDL_sensors[i].instance_id = SDL_GetNextSensorInstanceID();
+            SDL_sensors[i].instance_id = SDL_GetNextObjectID();
             ++i;
         }
         if (SDL_motion_manager.gyroAvailable) {
             SDL_sensors[i].type = SDL_SENSOR_GYRO;
-            SDL_sensors[i].instance_id = SDL_GetNextSensorInstanceID();
+            SDL_sensors[i].instance_id = SDL_GetNextObjectID();
             ++i;
         }
         SDL_sensors_count = sensors_count;

src/sensor/n3ds/SDL_n3dssensor.c

@@ -54,9 +54,9 @@ static int N3DS_SensorInit(void)
     }
 
     N3DS_sensors[0].type = SDL_SENSOR_ACCEL;
-    N3DS_sensors[0].instance_id = SDL_GetNextSensorInstanceID();
+    N3DS_sensors[0].instance_id = SDL_GetNextObjectID();
     N3DS_sensors[1].type = SDL_SENSOR_GYRO;
-    N3DS_sensors[1].instance_id = SDL_GetNextSensorInstanceID();
+    N3DS_sensors[1].instance_id = SDL_GetNextObjectID();
     return 0;
 }
 

src/sensor/vita/SDL_vitasensor.c

@@ -56,9 +56,9 @@ static int SDL_VITA_SensorInit(void)
     }
 
     SDL_sensors[0].type = SDL_SENSOR_ACCEL;
-    SDL_sensors[0].instance_id = SDL_GetNextSensorInstanceID();
+    SDL_sensors[0].instance_id = SDL_GetNextObjectID();
     SDL_sensors[1].type = SDL_SENSOR_GYRO;
-    SDL_sensors[1].instance_id = SDL_GetNextSensorInstanceID();
+    SDL_sensors[1].instance_id = SDL_GetNextObjectID();
 
     return 0;
 }

src/sensor/windows/SDL_windowssensor.c

@@ -315,7 +315,7 @@ static int ConnectSensor(ISensor *sensor)
     ++SDL_num_sensors;
 
     SDL_zerop(new_sensor);
-    new_sensor->id = SDL_GetNextSensorInstanceID();
+    new_sensor->id = SDL_GetNextObjectID();
     new_sensor->sensor = sensor;
     new_sensor->type = type;
     new_sensor->name = name;

src/video/SDL_sysvideo.h

@@ -364,7 +364,6 @@ struct SDL_VideoDevice
     SDL_Window *windows;
     SDL_Window *grabbed_window;
     Uint8 window_magic;
-    SDL_WindowID next_object_id;
     Uint32 clipboard_sequence;
     SDL_ClipboardDataCallback clipboard_callback;
     SDL_ClipboardCleanupCallback clipboard_cleanup;

src/video/SDL_video.c

@@ -517,7 +517,6 @@ int SDL_VideoInit(const char *driver_name)
     pre_driver_error. */
     _this = video;
     _this->name = bootstrap[i]->name;
-    _this->next_object_id = 1;
     _this->thread = SDL_ThreadID();
 
     /* Set some very sane GL defaults */
@@ -664,7 +663,7 @@ SDL_DisplayID SDL_AddVideoDisplay(const SDL_VideoDisplay *display, SDL_bool send
     _this->displays = displays;
     _this->displays[_this->num_displays++] = new_display;
 
-    id = _this->next_object_id++;
+    id = SDL_GetNextObjectID();
     SDL_memcpy(new_display, display, sizeof(*new_display));
     new_display->id = id;
     new_display->device = _this;
@@ -1950,7 +1949,7 @@ static SDL_Window *SDL_CreateWindowInternal(const char *title, int x, int y, int
         return NULL;
     }
     window->magic = &_this->window_magic;
-    window->id = _this->next_object_id++;
+    window->id = SDL_GetNextObjectID();
     window->windowed.x = window->x = x;
     window->windowed.y = window->y = y;
     window->windowed.w = window->w = w;
@@ -2116,7 +2115,7 @@ SDL_Window *SDL_CreateWindowFrom(const void *data)
         return NULL;
     }
     window->magic = &_this->window_magic;
-    window->id = _this->next_object_id++;
+    window->id = SDL_GetNextObjectID();
     window->flags = flags;
     window->is_destroying = SDL_FALSE;
     window->display_scale = 1.0f;