(This is the documentation for SDL3, which is under heavy development and the API is changing! SDL2 is the current stable version!)

SDL_CreateThread

Create a new thread with a default stack size.

Header File

Defined in <SDL3/SDL_thread.h>

Syntax

SDL_Thread * SDL_CreateThread(SDL_ThreadFunction fn, const char *name, void *data);

Function Parameters

Return Value

Returns an opaque pointer to the new thread object on success, NULL if the new thread could not be created; call SDL_GetError() for more information.

Remarks

This is a convenience function, equivalent to calling SDL_CreateThreadWithProperties with the following properties set:

• SDL_PROP_THREAD_CREATE_ENTRY_FUNCTION_POINTER: fn
• SDL_PROP_THREAD_CREATE_NAME_STRING: name
• SDL_PROP_THREAD_CREATE_USERDATA_POINTER: data

Note that this "function" is actually a macro that calls an internal function with two extra parameters not listed here; they are hidden through preprocessor macros and are needed to support various C runtimes at the point of the function call. Language bindings that aren't using the C headers will need to deal with this.

Usually, apps should just call this function the same way on every platform and let the macros hide the details.

Version

This function is available since SDL 3.0.0.

Code Examples

#include <SDL3/SDL.h>

/* Very simple thread - counts 0 to 9 delaying 50ms between increments */
static int TestThread(void *ptr)
{
    int cnt;

    for (cnt = 0; cnt < 10; ++cnt) {
        SDL_Log("Thread counter: %d", cnt);
        SDL_Delay(50);
    }

    return cnt;
}

int main(int argc, char *argv[])
{
    SDL_Thread *thread;
    int         threadReturnValue;

    SDL_Log("Simple SDL_CreateThread test:");

    /* Simply create a thread */
    thread = SDL_CreateThread(TestThread, "TestThread", (void *)NULL);

    if (NULL == thread) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_CreateThread failed: %s", SDL_GetError());
    } else {
        SDL_WaitThread(thread, &threadReturnValue);
        SDL_Log("Thread returned value: %d", threadReturnValue);
    }

    return 0;
}

/*
 * Output:
 * Simple SDL_CreateThread test:
 * Thread counter: 0
 * Thread counter: 1
 * Thread counter: 2
 * Thread counter: 3
 * Thread counter: 4
 * Thread counter: 5
 * Thread counter: 6
 * Thread counter: 7
 * Thread counter: 8
 * Thread counter: 9
 * Thread returned value: 10
 */

See Also

• SDL_CreateThreadWithProperties
• SDL_WaitThread

CategoryAPI, CategoryAPIFunction, CategoryThread