Enum shuttle::MaxSteps

#[non_exhaustive]
pub enum MaxSteps {
    None,
    FailAfter(usize),
    ContinueAfter(usize),
}

Specifies an upper bound on the number of steps a single iteration of a Shuttle test can take, and how to react when the bound is reached.

A “step” is an atomic region (all the code between two yieldpoints). For example, all the (non-concurrency-operation) code between acquiring and releasing a Mutex is a single step. Shuttle can bound the maximum number of steps a single test iteration can take to prevent infinite loops. If the bound is hit, the test can either fail (FailAfter) or continue to the next iteration (ContinueAfter).

The steps bound can be used to protect against livelock and fairness issues. For example, if a thread is waiting for another thread to make progress, but the chosen Scheduler never schedules that thread, a livelock occurs and the test will not terminate without a step bound.

By default, Shuttle fails a test after 1,000,000 steps.

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.

None

Do not enforce any bound on the maximum number of steps

FailAfter(usize)

Fail the test (by panicking) after the given number of steps

ContinueAfter(usize)

When the given number of steps is reached, stop the current iteration of the test and begin a new iteration

Trait Implementations

impl Clone for MaxSteps

fn clone(&self) -> MaxSteps

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MaxSteps

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

Formats the value using the given formatter.

impl PartialEq for MaxSteps

fn eq(&self, other: &MaxSteps) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for MaxSteps

impl Eq for MaxSteps

impl StructuralPartialEq for MaxSteps