jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include <errno.h>
8#include <sched.h>
9#include <syscall.h>
10
11extern "C" {
12
13// https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_yield.html
14int sched_yield()
15{
16 int rc = syscall(SC_yield);
17 __RETURN_WITH_ERRNO(rc, rc, -1);
18}
19
20// https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_get_priority_min.html
21int sched_get_priority_min([[maybe_unused]] int policy)
22{
23 return THREAD_PRIORITY_MIN;
24}
25
26// https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_get_priority_max.html
27int sched_get_priority_max([[maybe_unused]] int policy)
28{
29 return THREAD_PRIORITY_MAX;
30}
31
32// https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_setparam.html
33int sched_setparam(pid_t pid, const struct sched_param* param)
34{
35 Syscall::SC_scheduler_parameters_params parameters {
36 .pid_or_tid = pid,
37 .mode = Syscall::SchedulerParametersMode::Process,
38 .parameters = *param,
39 };
40 int rc = syscall(SC_scheduler_set_parameters, ¶meters);
41 __RETURN_WITH_ERRNO(rc, rc, -1);
42}
43
44// https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_getparam.html
45int sched_getparam(pid_t pid, struct sched_param* param)
46{
47 Syscall::SC_scheduler_parameters_params parameters {
48 .pid_or_tid = pid,
49 .mode = Syscall::SchedulerParametersMode::Process,
50 .parameters = {},
51 };
52 int rc = syscall(SC_scheduler_get_parameters, ¶meters);
53 if (rc == 0)
54 *param = parameters.parameters;
55 __RETURN_WITH_ERRNO(rc, rc, -1);
56}
57}