1//===-- Implementation of sched_rr_get_interval ---------------------------===//
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/sched/sched_rr_get_interval.h"
10
11#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
12#include "src/__support/common.h"
13#include "src/__support/libc_errno.h"
14#include "src/__support/macros/config.h"
15
16#include <sys/syscall.h> // For syscall numbers.
17
18#ifdef SYS_sched_rr_get_interval_time64
19#include <linux/time_types.h> // For __kernel_timespec.
20#endif
21
22namespace LIBC_NAMESPACE_DECL {
23
24LLVM_LIBC_FUNCTION(int, sched_rr_get_interval,
25 (pid_t tid, struct timespec *tp)) {
26#ifdef SYS_sched_rr_get_interval
27 int ret =
28 LIBC_NAMESPACE::syscall_impl<int>(SYS_sched_rr_get_interval, tid, tp);
29#elif defined(SYS_sched_rr_get_interval_time64)
30 // The difference between the and SYS_sched_rr_get_interval
31 // SYS_sched_rr_get_interval_time64 syscalls is the data type used for the
32 // time interval parameter: the latter takes a struct __kernel_timespec
33 int ret;
34 if (tp) {
35 struct __kernel_timespec ts32;
36 ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_sched_rr_get_interval_time64,
37 tid, &ts32);
38 if (ret == 0) {
39 tp->tv_sec = ts32.tv_sec;
40 tp->tv_nsec = static_cast<long int>(ts32.tv_nsec);
41 }
42 } else
43 // When tp is a nullptr, we still do the syscall to set ret and errno
44 ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_sched_rr_get_interval_time64,
45 tid, nullptr);
46#else
47#error \
48 "sched_rr_get_interval and sched_rr_get_interval_time64 syscalls not available."
49#endif
50 if (ret < 0) {
51 libc_errno = -ret;
52 return -1;
53 }
54 return 0;
55}
56
57} // namespace LIBC_NAMESPACE_DECL
58

source code of libc/src/sched/linux/sched_rr_get_interval.cpp