###### (This is the documentation for SDL3, which is the current stable version. [SDL2](https://wiki.libsdl.org/SDL2/) was the previous version!) # SDL_SetTLS Set the current thread's value associated with a thread local storage ID. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_thread.h) ## Syntax ```c bool SDL_SetTLS(SDL_TLSID *id, const void *value, SDL_TLSDestructorCallback destructor); ``` ## Function Parameters | | | | | ------------------------------------------------------ | -------------- | ------------------------------------------------------------------------ | | [SDL_TLSID](SDL_TLSID) * | **id** | a pointer to the thread local storage ID, may not be NULL. | | const void * | **value** | the value to associate with the ID for the current thread. | | [SDL_TLSDestructorCallback](SDL_TLSDestructorCallback) | **destructor** | a function called when the thread exits, to free the value, may be NULL. | ## Return Value (bool) Returns true on success or false on failure; call [SDL_GetError](SDL_GetError)() for more information. ## Remarks If the thread local storage ID is not initialized (the value is 0), a new ID will be created in a thread-safe way, so all calls using a pointer to the same ID will refer to the same local storage. Note that replacing a value from a previous call to this function on the same thread does _not_ call the previous value's destructor! `destructor` can be NULL; it is assumed that `value` does not need to be cleaned up if so. ## Thread Safety It is safe to call this function from any thread. ## Version This function is available since SDL 3.1.3. ## See Also - [SDL_GetTLS](SDL_GetTLS) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryThread](CategoryThread)