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

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