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use std::{fs::File, os::unix::prelude::*, path::Path};
use nix::{
fcntl::{self, FcntlArg, FdFlag, OFlag},
sched,
unistd::Pid,
};
use common::error::*;
use super::fs;
pub fn set_blocking(fd: RawFd, blocking: bool) -> Result<()> {
let flags = unsafe {
OFlag::from_bits_unchecked(fcntl::fcntl(fd, FcntlArg::F_GETFL).context("fcntl(F_GETFL)")?)
};
let new_flags = if blocking {
flags & !OFlag::O_NONBLOCK
} else {
flags | OFlag::O_NONBLOCK
};
if new_flags != flags {
fcntl::fcntl(fd, FcntlArg::F_SETFL(new_flags)).context("fcntl(F_SETFL)")?;
}
Ok(())
}
pub fn set_cloexec(fd: RawFd, cloexec: bool) -> Result<()> {
let flags = unsafe {
FdFlag::from_bits_unchecked(fcntl::fcntl(fd, FcntlArg::F_GETFD).context("fcntl(F_GETFD)")?)
};
let new_flags = if cloexec {
flags | FdFlag::FD_CLOEXEC
} else {
flags & !FdFlag::FD_CLOEXEC
};
if new_flags != flags {
fcntl::fcntl(fd, FcntlArg::F_SETFD(new_flags)).context("fcntl(F_SETFD)")?;
}
Ok(())
}
pub fn nproc() -> Result<usize> {
const MAXCPU: usize = sched::CpuSet::count();
let affinity = sched::sched_getaffinity(Pid::from_raw(0)).context("sched_getaffinity()")?;
let mut count = 0;
for cpu in 0..MAXCPU {
if affinity.is_set(cpu).unwrap() {
count += 1;
}
}
Ok(count)
}
pub fn lock<P: AsRef<Path>>(path: P, exclusive: bool, blocking: bool) -> Result<File> {
use fcntl::FlockArg::*;
if let Some(parent) = path.as_ref().parent() {
fs::mkdir(parent)?;
}
let arg = match (exclusive, blocking) {
(true, true) => LockExclusive,
(true, false) => LockExclusiveNonblock,
(false, true) => LockShared,
(false, false) => LockSharedNonblock,
};
let file = fs::create(path.as_ref())?;
fcntl::flock(file.as_raw_fd(), arg)
.with_context(|| format!("flock failed on {:?}", path.as_ref()))?;
Ok(file)
}
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