Enum SessionEntryError 

#[non_exhaustive]
pub enum SessionEntryError {
    Reentered {
        backend: &'static str,
    },
    Contended {
        backend: &'static str,
        message: String,
    },
    IncompatibleContext {
        backend: &'static str,
        message: String,
    },
    ResourcePoisoned {
        backend: &'static str,
        resource: &'static str,
    },
    Executor {
        backend: &'static str,
        source: BoxError,
    },
}

Why a backend refused to open an execution session.

The session callback has not run when this error is returned. Contention that the backend can wait out (another thread holding an overlapping CPU resource permit) is waited for, not reported; this type covers only states that waiting cannot resolve.

Examples

use tenferro_tensor::{Error, ErrorKind, SessionEntryError};

let entry = SessionEntryError::IncompatibleContext {
    backend: "CpuBackend",
    message: "operation backend does not match the active execution scope".into(),
};
let error = Error::from(entry);
assert_eq!(error.kind(), ErrorKind::RuntimeState);
assert!(std::error::Error::source(&error).is_some());

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Reentered

An execution for this backend is already active on the calling thread (or its managed worker scope), so opening another session would nest provider or resource exclusion.

Fields

backend: &'static str

Backend that rejected the entry.

Contended

A resource that admission cannot wait for is held by another user, such as a caller-managed CPU domain already executing elsewhere.

Fields

backend: &'static str

Backend that rejected the entry.

message: String

Which resource was busy.

IncompatibleContext

The session cannot be opened in the declared or active execution context, for example an execution scope entered for a different backend.

Fields

backend: &'static str

Backend that rejected the entry.

message: String

Which context requirement failed.

ResourcePoisoned

Admission state was poisoned by an earlier panic and cannot be trusted.

Fields

backend: &'static str

Backend that rejected the entry.

resource: &'static str

Poisoned admission resource.

Executor

The backend’s executor could not be entered.

Fields

backend: &'static str

Backend that rejected the entry.

source: BoxError

Typed executor failure.

Implementations

impl SessionEntryError

pub fn backend(&self) -> &'static str

Return the backend that rejected the session entry.

Examples

use tenferro_tensor::SessionEntryError;

let error = SessionEntryError::ResourcePoisoned {
    backend: "CpuBackend",
    resource: "the CPU resource arbiter",
};
assert_eq!(error.backend(), "CpuBackend");

pub fn kind(&self) -> ErrorKind

Return the coarse classification of this failure.

Every session-entry failure is invalid or unavailable execution state.

Examples

use tenferro_tensor::{ErrorKind, SessionEntryError};

let error = SessionEntryError::Contended {
    backend: "CpuBackend",
    message: "caller-managed CPU domain".into(),
};
assert_eq!(error.kind(), ErrorKind::RuntimeState);

Trait Implementations

impl Debug for SessionEntryError

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

Formats the value using the given formatter.

impl Display for SessionEntryError

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

Formats the value using the given formatter.

impl Error for SessionEntryError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<SessionEntryError> for Error

fn from(source: SessionEntryError) -> Self

Converts to this type from the input type.