OSSL_SLEEP(3ossl)

💤 OSSL_SLEEP 💤

okay bestie, welcome to the manual page for OSSL_sleep, straight out of the OpenSSL fam (we're on 3.5.9, if you were wondering 👀). It's a lil function, it's a simple function, and honestly? It's giving "nap time, but make it C." Let's get into it 💅

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✨ NAME ✨

OSSL_sleep — delay execution for a specified number of milliseconds

yes girl, that's literally it. it pauses your thread. that's the whole job 🛌

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🌸 SYNOPSIS 🌸

#include <openssl/crypto.h>

void OSSL_sleep(uint64_t millis);

look at her. one header, one function, zero drama 🎀

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💖 DESCRIPTION 💖

So OSSL_sleep() is a convenience function — it delays execution of the calling thread for (at least) millis milliseconds. Cute, right? Yeah. But listen, bestie, because this is the part where I hold your hand and say the delay is NOT guaranteed 😭

It might get affected by literally any of these:

• system activity doing its own thing in the background
• the time spent processing the call itself (the function has overhead, she's not free)
• limitation on the underlying system call parameter size — the syscall underneath can only count so high
• system timer granularity — your clock's resolution, basically, the vibe check of your hardware

And here are the two big numbers you need to know, no cap:

• On Windows, the maximum amount of time it will sleep is 49 days
• On systems where the regular sleep(3) is used as the underlying system call, the maximum sleep time is about 136 years

136 years. bestie. that's not a sleep, that's a ✨generational commitment✨ 💀

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🙈 RETURN VALUES 🙈

OSSL_sleep() does not return any value.

Nothing. Nada. Zilch. It returns void, so don't you dare go assigning it to anything 🫶

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🦋 HISTORY 🦋

OSSL_sleep() was added in OpenSSL 3.2.

she's new-ish, she's fresh, she's iconic 👑

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👑 COPYRIGHT 👑

Copyright 2022-2023 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

fr fr read the license, it's the rules 🫡

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and that's the whole page, bestie 💖 go forth and sleep responsibly 💤

signing off from the OpenSSL 3.5.9 manual, dated 2026-09-29 — mwah 💅✨