Enum ThreadTerminationOption 

#[non_exhaustive]
pub enum ThreadTerminationOption {
    Normal,
    Prompt,
    Never,
}

What a thread does when its execution is asked to terminate (ThreadTerminationOptions).

An execution cannot finish terminating while any of its threads refuses to stop, so this decides whether Execution::terminate completes promptly or waits.

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.

Normal

Stop with the execution. The default, and what an unattended host wants almost everywhere.

Prompt

Refuse to stop unless the execution is told to override refusals.

When every remaining thread chooses this, the engine posts UIMsg_NonTerminatableThreadsArePreventingTermination and waits. On a station with somebody watching, that is a question. On a headless host it is a termination that never finishes unless the host handles that message and overrides, so treat this as something to notice rather than something to set casually.

Never

Never stop with the execution; the thread runs to its own end first.

For work that must not be cut in half, such as leaving hardware in a safe state. The execution cannot end until the thread does, so anything choosing this needs a bounded amount of work left to do.

Implementations

impl ThreadTerminationOption

pub const fn from_bits(bits: i32) -> Result<Self, i32>

Maps the engine’s number onto an option.

Errors

The raw value, when it is one this build does not name.

pub const fn bits(self) -> i32

The engine’s number for this option.

pub const fn stops_with_execution(self) -> bool

Whether a thread with this option stops when its execution terminates.

False for both Prompt and Never, so a host can tell in one call whether a thread is going to hold up a termination.

Trait Implementations

impl Clone for ThreadTerminationOption

fn clone(&self) -> ThreadTerminationOption

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ThreadTerminationOption

impl Debug for ThreadTerminationOption

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

Formats the value using the given formatter.

impl Eq for ThreadTerminationOption

impl Hash for ThreadTerminationOption

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ThreadTerminationOption

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ThreadTerminationOption