Struct linux_futex::PiFutex

#[repr(transparent)]
pub struct PiFutex<Scope> {
    pub value: AtomicU32,
    /* private fields */
}

A Linux-specific priority inheriting fast user-space locking primitive.

Unlike with a regular Futex, the value of a PiFutex has meaning to the Linux kernel, taking away some flexibility. User-space must follow the assumed protocol to allow the kernel to properly implement priority inheritance.

See the Priority-inheritance futexes section of the Linux futex man page for details.

PiFutex<Private> may only be used from the same address space (the same process) and is faster than a PiFutex<Shared>, which may be used accross address spaces (processes).

Fields

value: AtomicU32

Implementations

impl<S> PiFutex<S>

pub const fn new(value: u32) -> Self

Create a new PiFutex with an initial value.

pub const WAITERS: u32 = 2_147_483_648u32

The FUTEX_WAITERS bit that indicates there are threads waiting.

pub const OWNER_DIED: u32 = 1_073_741_824u32

The FUTEX_OWNER_DIED bit that indicates the owning thread died.

pub const TID_MASK: u32 = 1_073_741_823u32

The bits that are used for storing the thread id (FUTEX_TID_MASK).

impl<S: Scope> PiFutex<S>

pub fn lock_pi(&self) -> Result<(), TryAgainError>

See FUTEX_LOCK_PI in the Linux futex man page.

pub fn lock_pi_until(&self, timeout: impl Timeout) -> Result<(), TimedLockError>

See FUTEX_LOCK_PI in the Linux futex man page.

pub fn trylock_pi(&self) -> Result<(), TryAgainError>

See FUTEX_TRYLOCK_PI in the Linux futex man page.

pub fn unlock_pi(&self)

See FUTEX_UNLOCK_PI in the Linux futex man page.

Trait Implementations

impl<S> Debug for PiFutex<S>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<S> Default for PiFutex<S>

fn default() -> Self

Returns the “default value” for a type.