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//! Feature tests for OS functionality
pub use self::os::*;
#[cfg(linux_android)]
mod os {
use crate::sys::utsname::uname;
use crate::Result;
use std::os::unix::ffi::OsStrExt;
use std::sync::atomic::{AtomicUsize, Ordering};
// Features:
// * atomic cloexec on socket: 2.6.27
// * pipe2: 2.6.27
// * accept4: 2.6.28
static VERS_UNKNOWN: usize = 1;
static VERS_2_6_18: usize = 2;
static VERS_2_6_27: usize = 3;
static VERS_2_6_28: usize = 4;
static VERS_3: usize = 5;
#[inline]
fn digit(dst: &mut usize, b: u8) {
*dst *= 10;
*dst += (b - b'0') as usize;
}
fn parse_kernel_version() -> Result<usize> {
let u = uname()?;
let mut curr: usize = 0;
let mut major: usize = 0;
let mut minor: usize = 0;
let mut patch: usize = 0;
for &b in u.release().as_bytes() {
if curr >= 3 {
break;
}
match b {
b'.' | b'-' => {
curr += 1;
}
b'0'..=b'9' => match curr {
0 => digit(&mut major, b),
1 => digit(&mut minor, b),
_ => digit(&mut patch, b),
},
_ => break,
}
}
Ok(if major >= 3 {
VERS_3
} else if major >= 2 {
if minor >= 7 {
VERS_UNKNOWN
} else if minor >= 6 {
if patch >= 28 {
VERS_2_6_28
} else if patch >= 27 {
VERS_2_6_27
} else {
VERS_2_6_18
}
} else {
VERS_UNKNOWN
}
} else {
VERS_UNKNOWN
})
}
fn kernel_version() -> Result<usize> {
static KERNEL_VERS: AtomicUsize = AtomicUsize::new(0);
let mut kernel_vers = KERNEL_VERS.load(Ordering::Relaxed);
if kernel_vers == 0 {
kernel_vers = parse_kernel_version()?;
KERNEL_VERS.store(kernel_vers, Ordering::Relaxed);
}
Ok(kernel_vers)
}
/// Check if the OS supports atomic close-on-exec for sockets
pub fn socket_atomic_cloexec() -> bool {
kernel_version()
.map(|version| version >= VERS_2_6_27)
.unwrap_or(false)
}
#[test]
pub fn test_parsing_kernel_version() {
assert!(kernel_version().unwrap() > 0);
}
}
#[cfg(any(
freebsdlike, // FreeBSD since 10.0 DragonFlyBSD since ???
netbsdlike, // NetBSD since 6.0 OpenBSD since 5.7
target_os = "hurd", // Since glibc 2.28
target_os = "illumos", // Since ???
target_os = "redox", // Since 1-july-2020
))]
mod os {
/// Check if the OS supports atomic close-on-exec for sockets
pub const fn socket_atomic_cloexec() -> bool {
true
}
}
#[cfg(any(
target_os = "aix",
apple_targets,
target_os = "fuchsia",
target_os = "haiku",
target_os = "solaris"
))]
mod os {
/// Check if the OS supports atomic close-on-exec for sockets
pub const fn socket_atomic_cloexec() -> bool {
false
}
}