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//! `Timespec` and related types, which are used by multiple public API
//! modules.
#[cfg(not(fix_y2038))]
use crate::backend::c;
/// `struct timespec`
#[cfg(not(fix_y2038))]
pub type Timespec = c::timespec;
/// `struct timespec`
#[cfg(fix_y2038)]
#[derive(Debug, Clone, Copy)]
#[repr(C)]
pub struct Timespec {
/// Seconds.
pub tv_sec: Secs,
/// Nanoseconds. Must be less than 1_000_000_000.
pub tv_nsec: Nsecs,
}
/// A type for the `tv_sec` field of [`Timespec`].
#[cfg(not(fix_y2038))]
#[allow(deprecated)]
pub type Secs = c::time_t;
/// A type for the `tv_sec` field of [`Timespec`].
#[cfg(fix_y2038)]
pub type Secs = i64;
/// A type for the `tv_sec` field of [`Timespec`].
#[cfg(any(
fix_y2038,
linux_raw,
all(libc, target_arch = "x86_64", target_pointer_width = "32")
))]
pub type Nsecs = i64;
/// A type for the `tv_nsec` field of [`Timespec`].
#[cfg(all(
not(fix_y2038),
libc,
not(all(target_arch = "x86_64", target_pointer_width = "32"))
))]
pub type Nsecs = c::c_long;
/// On 32-bit glibc platforms, `timespec` has anonymous padding fields, which
/// Rust doesn't support yet (see `unnamed_fields`), so we define our own
/// struct with explicit padding, with bidirectional `From` impls.
#[cfg(fix_y2038)]
#[repr(C)]
#[derive(Debug, Clone)]
pub(crate) struct LibcTimespec {
pub(crate) tv_sec: Secs,
#[cfg(target_endian = "big")]
padding: core::mem::MaybeUninit<u32>,
pub(crate) tv_nsec: i32,
#[cfg(target_endian = "little")]
padding: core::mem::MaybeUninit<u32>,
}
#[cfg(fix_y2038)]
impl From<LibcTimespec> for Timespec {
#[inline]
fn from(t: LibcTimespec) -> Self {
Self {
tv_sec: t.tv_sec,
tv_nsec: t.tv_nsec as _,
}
}
}
#[cfg(fix_y2038)]
impl From<Timespec> for LibcTimespec {
#[inline]
fn from(t: Timespec) -> Self {
Self {
tv_sec: t.tv_sec,
tv_nsec: t.tv_nsec as _,
padding: core::mem::MaybeUninit::uninit(),
}
}
}
#[test]
fn test_sizes() {
assert_eq_size!(Secs, u64);
const_assert!(core::mem::size_of::<Timespec>() >= core::mem::size_of::<(u64, u32)>());
const_assert!(core::mem::size_of::<Nsecs>() >= 4);
let mut t = Timespec {
tv_sec: 0,
tv_nsec: 0,
};
// `tv_nsec` needs to be able to hold nanoseconds up to a second.
t.tv_nsec = 999_999_999_u32 as _;
assert_eq!(t.tv_nsec as u64, 999_999_999_u64);
// `tv_sec` needs to be able to hold more than 32-bits of seconds.
t.tv_sec = 0x1_0000_0000_u64 as _;
assert_eq!(t.tv_sec as u64, 0x1_0000_0000_u64);
}
// Test that our workarounds are needed.
#[cfg(fix_y2038)]
#[test]
#[allow(deprecated)]
fn test_fix_y2038() {
assert_eq_size!(libc::time_t, u32);
}