cosmopolitan/libc/calls/sched_get_priority_max.c
2023-04-27 05:44:32 -07:00

53 lines
2.8 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/sched-sysv.internal.h"
#include "libc/dce.h"
#include "libc/intrin/describeflags.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/sysv/consts/sched.h"
#include "libc/sysv/errfuns.h"
static int sys_sched_get_priority_max_netbsd(int policy) {
if (policy == SCHED_OTHER) {
return -1;
} else if (policy == SCHED_RR || policy == SCHED_FIFO) {
return 63; // NetBSD Libc needs 19 system calls to compute this!
} else {
return einval();
}
}
/**
* Returns maximum `sched_param::sched_priority` for `policy`.
*
* @return priority, or -1 w/ errno
* @raise ENOSYS on XNU, Windows, OpenBSD
* @raise EINVAL if `policy` is invalid
*/
int sched_get_priority_max(int policy) {
int rc;
if (IsNetbsd()) {
rc = sys_sched_get_priority_max_netbsd(policy);
} else {
rc = sys_sched_get_priority_max(policy);
}
STRACE("sched_get_priority_max(%s) → %d% m", DescribeSchedPolicy(policy), rc);
return rc;
}