cosmopolitan/libc/proc/sched_setaffinity.c
2024-07-19 19:38:00 -07:00

72 lines
3.5 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 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/sched-sysv.internal.h"
#include "libc/calls/struct/cpuset.h"
#include "libc/calls/syscall_support-nt.internal.h"
#include "libc/dce.h"
#include "libc/intrin/strace.h"
#include "libc/nt/errors.h"
#include "libc/nt/process.h"
#include "libc/nt/runtime.h"
#include "libc/proc/proc.internal.h"
#include "libc/sysv/errfuns.h"
static dontinline textwindows int sys_sched_setaffinity_nt(
int pid, uint64_t size, const cpu_set_t *bitset) {
int64_t handle;
if (!(handle = __proc_handle(pid))) {
return esrch();
}
if (SetProcessAffinityMask(handle, bitset->__bits[0])) {
return 0;
} else if (GetLastError() == kNtErrorInvalidHandle) {
return esrch();
} else {
return __winerr();
}
}
/**
* Asks kernel to only schedule process on particular CPUs.
*
* Affinity masks are inherited across fork() and execve() boundaries.
*
* @param pid is the process or process id (or 0 for caller)
* @param size is bytes in bitset, which should be `sizeof(cpuset_t)`
* @return 0 on success, or -1 w/ errno
* @raise ENOSYS if not Linux, FreeBSD, NetBSD, or Windows
* @see pthread_getaffinity_np() for threads
*/
int sched_setaffinity(int pid, size_t size, const cpu_set_t *bitset) {
int rc;
if (size != sizeof(cpu_set_t)) {
rc = einval();
} else if (IsWindows()) {
rc = sys_sched_setaffinity_nt(pid, size, bitset);
} else if (IsFreebsd()) {
rc = sys_sched_setaffinity_freebsd(CPU_LEVEL_WHICH, CPU_WHICH_PID, pid, 32,
bitset);
} else if (IsNetbsd()) {
rc = sys_sched_setaffinity_netbsd(P_ALL_LWPS, pid, 32, bitset);
} else {
rc = sys_sched_setaffinity(pid, size, bitset);
}
STRACE("sched_setaffinity(%d, %'zu, %p) → %d% m", pid, size, bitset, rc);
return rc;
}