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Use this function to create a new thread.


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

Function Parameters


the function to call in the new thread; see Remarks for details


the name of the thread; see Remarks for details


a pointer that is passed to fn

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.

Code Examples

#include <stdio.h>
#include "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) {
        printf("\nThread counter: %d", cnt);

    return cnt;

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

    printf("\nSimple SDL_CreateThread test:");

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

    if (NULL == thread) {
        printf("\nSDL_CreateThread failed: %s\n", SDL_GetError());
    } else {
        SDL_WaitThread(thread, &threadReturnValue);
        printf("\nThread returned value: %d", threadReturnValue);

    return 0;


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


SDL_CreateThread() creates a new thread of execution that shares all of its parent's global memory, signal handlers, file descriptors, etc, and runs the function fn, passing it the void pointer data. The thread quits when fn returns.

The function prototype for fn is:

int SDL_ThreadFunction(void* data)
  • where its parameter is:

There are no requirements for thread naming conventions, so long as the string is null-terminated UTF-8, but these guidelines are helpful in choosing a name:

If a system imposes requirements, SDL will try to munge the string for it (truncate, etc), but the original string contents will be available from SDL_GetThreadName().

CategoryAPI, CategoryThread

None: SDL_CreateThread (last edited 2017-03-11 22:47:30 by PhilippWiesemann)

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