###### (This is the documentation for SDL3, which is the current stable version. [SDL2](https://wiki.libsdl.org/SDL2/) was the previous version!) # SDL_WaitThread Wait for a thread to finish. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_thread.h) ## Syntax ```c void SDL_WaitThread(SDL_Thread *thread, int *status); ``` ## Function Parameters | | | | | -------------------------- | ---------- | -------------------------------------------------------------------------------------------------------------------------------------------- | | [SDL_Thread](SDL_Thread) * | **thread** | the [SDL_Thread](SDL_Thread) pointer that was returned from the [SDL_CreateThread](SDL_CreateThread)() call that started this thread. | | int * | **status** | pointer to an integer that will receive the value returned from the thread function by its 'return', or NULL to not receive such value back. | ## Remarks Threads that haven't been detached will remain (as a "zombie") until this function cleans them up. Not doing so is a resource leak. Once a thread has been cleaned up through this function, the [SDL_Thread](SDL_Thread) that references it becomes invalid and should not be referenced again. As such, only one thread may call [SDL_WaitThread](SDL_WaitThread)() on another. The return code for the thread function is placed in the area pointed to by `status`, if `status` is not NULL. You may not wait on a thread that has been used in a call to [SDL_DetachThread](SDL_DetachThread)(). Use either that function or this one, but not both, or behavior is undefined. It is safe to pass a NULL thread to this function; it is a no-op. Note that the thread pointer is freed by this function and is not valid afterward. ## Version This function is available since SDL 3.1.3. ## See Also - [SDL_CreateThread](SDL_CreateThread) - [SDL_DetachThread](SDL_DetachThread) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryThread](CategoryThread)