Struct UnsupportedOptionsError

pub struct UnsupportedOptionsError { /* private fields */ }

Attempted to build a counter using options that the current kernel does not support.

This error is returned as the inner error from Builder::build or Group::add if the kernel indicates that the perf_event_attr arguments contained options that the current kernel does not support.

This can be used to implement feature detection and fall back to a config which uses fewer options.

Example

use perf_event::events::Software;
use perf_event::{Builder, UnsupportedOptionsError};

let mut builder = Builder::new(Software::DUMMY);

// The linux kernel will always return E2BIG when the size is less than
// PERF_ATTR_SIZE_VER0 (64) except if it is 0. This allows us to easily
// make an invalid call do figure out what size the kernel is expecting.
builder.attrs_mut().size = 1;

let error = builder.build().unwrap_err();

assert_eq!(error.kind(), std::io::ErrorKind::Unsupported);
assert_eq!(error.raw_os_error(), None);

let inner: &UnsupportedOptionsError = error.get_ref().unwrap().downcast_ref().unwrap();

println!("The expected size was {}", inner.expected_size());

Implementations

impl UnsupportedOptionsError

pub fn expected_size(&self) -> usize

The size that the kernel expected the perf_event_attr struct to be.

Trait Implementations

impl Debug for UnsupportedOptionsError

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

Formats the value using the given formatter.

impl Display for UnsupportedOptionsError

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

Formats the value using the given formatter.

impl Error for UnsupportedOptionsError

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.