1//===-- Implementation file for setitimer ---------------------------------===//
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#include "src/sys/time/setitimer.h"
9#include "hdr/types/struct_itimerval.h"
10#include "src/__support/OSUtil/syscall.h"
11#include "src/__support/common.h"
12#include "src/__support/libc_errno.h"
13#include <sys/syscall.h>
14
15namespace LIBC_NAMESPACE_DECL {
16
17LLVM_LIBC_FUNCTION(int, setitimer,
18 (int which, const struct itimerval *new_value,
19 struct itimerval *old_value)) {
20 long ret = 0;
21 if constexpr (sizeof(time_t) > sizeof(long)) {
22 // There is no SYS_setitimer_time64 call, so we can't use time_t directly,
23 // and need to convert it to long first.
24 long new_value32[4] = {static_cast<long>(new_value->it_interval.tv_sec),
25 new_value->it_interval.tv_usec,
26 static_cast<long>(new_value->it_value.tv_sec),
27 new_value->it_value.tv_usec};
28 long old_value32[4];
29
30 ret = LIBC_NAMESPACE::syscall_impl<long>(SYS_setitimer, which, new_value32,
31 old_value32);
32
33 if (!ret && old_value) {
34 old_value->it_interval.tv_sec = old_value32[0];
35 old_value->it_interval.tv_usec = old_value32[1];
36 old_value->it_value.tv_sec = old_value32[2];
37 old_value->it_value.tv_usec = old_value32[3];
38 }
39 } else {
40 ret = LIBC_NAMESPACE::syscall_impl<long>(SYS_setitimer, which, new_value,
41 old_value);
42 }
43
44 // On failure, return -1 and set errno.
45 if (ret < 0) {
46 libc_errno = static_cast<int>(-ret);
47 return -1;
48 }
49 return 0;
50}
51
52} // namespace LIBC_NAMESPACE_DECL
53

source code of libc/src/sys/time/linux/setitimer.cpp