SDL_SemWaitTimeout(3)

💖 SDL_SemWaitTimeout 💖

okay bestie, so this one's from the SDL API Reference and it lives in section 3 of the manual, iykyk — it's the ✨ timeout version ✨ of waiting on a semaphore. let's get into it 🦋

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✨ NAME ✨

SDL_SemWaitTimeout — lock a semaphore, but only wait up to a specified maximum time. like, she's got places to be 💅

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🌸 SYNOPSIS 🌸

#include "SDL.h" #include "SDL_thread.h"

int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout);

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🎀 DESCRIPTION 🎀

so SDL_SemWaitTimeout() is a varient of SDL_SemWait but with a max timeout value attached. the way it works is:

• if the value of the semaphore pointed to by sem is positive (greater than zero), it will atomically decrement the semaphore value and return 0 🫶
• otherwise, it will wait up to timeout milliseconds trying to lock the semaphore ⏳

ngl bestie, this function is to be avoided if possible 😭 because on some platforms it's implemented by polling the semaphore every millisecond in a busy loop. like it's just sitting there asking "is it ready yet? is it ready yet?" every single millisecond. exhausting. 💀

after SDL_SemWaitTimeout() is successful, the semaphore can be released and its count atomically incremented by a successful call to SDL_SemPost ✨

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⭐ RETURN VALUE ⭐

• Returns 0 if the semaphore was successfully locked 🎉
• Returns either SDL_MUTEX_TIMEOUT or -1 if the timeout period was exceeded or there was an error, respectivly 🙈

if the semaphore was not successfully locked, the semaphore will be unchanged. no cap. 🧚

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🌈 EXAMPLES 🌈

here's the vibe, bestie:

res = SDL_SemWaitTimeout(my_sem, WAIT_TIMEOUT_MILLISEC);

if (res == SDL_MUTEX_TIMEOUT) {
        return TRY_AGAIN;
}
if (res == -1) {
        return WAIT_ERROR;
}

...

SDL_SemPost(my_sem);

look at her go 😌👑

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💜 SEE ALSO 💜

• SDL_CreateSemaphore
• SDL_DestroySemaphore
• SDL_SemWait
• SDL_SemTryWait
• SDL_SemPost
• SDL_SemValue

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and that's the whole thing, bestie!! 🌸 this page is from SDL, dated Tue 11 Sep 2001, 23:00 — yes she's an old queen but she's still iconic 👑💖 mwah, go forth and semaphore responsibly 🦋✨