1//===-- Linux implementation of nanosleep function ------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "src/time/nanosleep.h"
10
11#include "src/__support/OSUtil/syscall.h" // For syscall functions.
12#include "src/__support/common.h"
13#include "src/errno/libc_errno.h"
14
15#include <stdint.h> // For int64_t.
16#include <sys/syscall.h> // For syscall numbers.
17
18namespace LIBC_NAMESPACE {
19
20LLVM_LIBC_FUNCTION(int, nanosleep,
21 (const struct timespec *req, struct timespec *rem)) {
22#if SYS_nanosleep
23 int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_nanosleep, ts: req, ts: rem);
24#elif defined(SYS_clock_nanosleep_time64)
25 static_assert(
26 sizeof(time_t) == sizeof(int64_t),
27 "SYS_clock_gettime64 requires struct timespec with 64-bit members.");
28 int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_clock_nanosleep_time64,
29 CLOCK_REALTIME, 0, req, rem);
30#else
31#error "SYS_nanosleep and SYS_clock_nanosleep_time64 syscalls not available."
32#endif
33
34 if (ret < 0) {
35 libc_errno = -ret;
36 return -1;
37 }
38 return ret;
39}
40
41} // namespace LIBC_NAMESPACE
42

source code of libc/src/time/linux/nanosleep.cpp