openssl/crypto/sleep.c
Richard Levitte f352c808ed For Unix, refactor OSSL_sleep() to use nanosleep() instead of usleep()
usleep() is obsolete since POSIX.1-2001 and removed in POSIX.1-2008,
in favor of nanosleep(), which has been present since POSIX.1-2001.

The exceptions for DJGPP and TANDEM are preserved.  Also, just in case
nanosleep() turns out to be unavailable on any Unix machinery that we
are unaware of, we allow a revert to using usleep() by defining
OPENSSL_USE_USLEEP.

Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/24173)
2024-05-22 09:59:32 +02:00

117 lines
3.1 KiB
C

/*
* Copyright 2022-2024 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
*/
#include <openssl/crypto.h>
#include "internal/e_os.h"
/* system-specific variants defining OSSL_sleep() */
#if defined(OPENSSL_SYS_UNIX) || defined(__DJGPP__)
# if defined(OPENSSL_USE_USLEEP) \
|| defined(__DJGPP__) \
|| (defined(__TANDEM) && defined(_REENTRANT))
/*
* usleep() was made obsolete by POSIX.1-2008, and nanosleep()
* should be used instead. However, nanosleep() isn't implemented
* on the platforms given above, so we still use it for those.
* Also, OPENSSL_USE_USLEEP can be defined to enable the use of
* usleep, if it turns out that nanosleep() is unavailable.
*/
# include <unistd.h>
void OSSL_sleep(uint64_t millis)
{
unsigned int s = (unsigned int)(millis / 1000);
unsigned int us = (unsigned int)((millis % 1000) * 1000);
if (s > 0)
sleep(s);
/*
* On NonStop with the PUT thread model, thread context switch is
* cooperative, with usleep() being a "natural" context switch point.
* We avoid checking us > 0 here, to allow that context switch to
* happen.
*/
usleep(us);
}
# elif defined(__TANDEM) && !defined(_REENTRANT)
# include <cextdecs.h(PROCESS_DELAY_)>
void OSSL_sleep(uint64_t millis)
{
/* HPNS does not support usleep for non threaded apps */
PROCESS_DELAY_(millis * 1000);
}
# else
/* nanosleep is defined by POSIX.1-2001 */
# include <time.h>
void OSSL_sleep(uint64_t millis)
{
struct timespec ts;
ts.tv_sec = (long int) (millis / 1000);
ts.tv_nsec = (long int) (millis % 1000) * 1000000ul;
nanosleep(&ts, NULL);
}
# endif
#elif defined(_WIN32) && !defined(OPENSSL_SYS_UEFI)
# include <windows.h>
void OSSL_sleep(uint64_t millis)
{
/*
* Windows' Sleep() takes a DWORD argument, which is smaller than
* a uint64_t, so we need to limit it to 49 days, which should be enough.
*/
DWORD limited_millis = (DWORD)-1;
if (millis < limited_millis)
limited_millis = (DWORD)millis;
Sleep(limited_millis);
}
#else
/* Fallback to a busy wait */
# include "internal/time.h"
static void ossl_sleep_secs(uint64_t secs)
{
/*
* sleep() takes an unsigned int argument, which is smaller than
* a uint64_t, so it needs to be limited to 136 years which
* should be enough even for Sleeping Beauty.
*/
unsigned int limited_secs = UINT_MAX;
if (secs < limited_secs)
limited_secs = (unsigned int)secs;
sleep(limited_secs);
}
static void ossl_sleep_millis(uint64_t millis)
{
const OSSL_TIME finish
= ossl_time_add(ossl_time_now(), ossl_ms2time(millis));
while (ossl_time_compare(ossl_time_now(), finish) < 0)
/* busy wait */ ;
}
void OSSL_sleep(uint64_t millis)
{
ossl_sleep_secs(millis / 1000);
ossl_sleep_millis(millis % 1000);
}
#endif /* defined(OPENSSL_SYS_UNIX) || defined(__DJGPP__) */