Struct ste::Tag

#[repr(transparent)]pub struct Tag(_);

A tag associated with a thread. Threads which are executed with Thread support tagging.

You must ensure that any thread trying to use values first is checked with the current tag through Tag::ensure_on_thread. This includes everything which poses a potential thread safety risk.

If that is done, you can safely implement Send for the type.

Examples

struct Foo {
    tag: ste::Tag,
    data: *mut (),
}

impl Foo {
    fn new() -> Self {
        Self {
            tag: ste::Tag::current_thread(),
            data: std::ptr::null_mut(),
        }
    }

    fn say_hello(&self) {
        self.tag.ensure_on_thread();
        println!("Hello from Foo");
    }
}

// Safety: the structure is explicitly tagged with the thread that created
// it, and we ensure everywhere where racy access might otherwise happen
// that it is on the creating thread.
unsafe impl Send for Foo {}

let thread = ste::Thread::new()?;

let foo = thread.submit(|| Foo::new())?;

assert!(!foo.tag.is_on_thread());

foo.say_hello(); // <- oops, this panics

thread.join()?;

Implementations

impl Tag

pub fn current_thread() -> Self

Get the tag associated with the current thread.

See Tag documentation for how to use.

Panics

Panics if not running on a tagged thread. Tagged threads are the ones created with Thread.

pub fn ensure_on_thread(&self)

Ensure that the tag is currently executing on the thread that created it.

See Tag documentation for how to use.

Panics

Panics if not running on a tagged thread. Tagged threads are the ones created with Thread.

Also panics unless called on the same thread that the tag was created on.

pub fn is_on_thread(&self) -> bool

Test if we’re currently on the tagged thread.

See Tag documentation for how to use.

Trait Implementations

impl Clone for Tag

fn clone(&self) -> Tag

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Tag

impl Debug for Tag

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

Formats the value using the given formatter.

impl Eq for Tag

impl Hash for Tag

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

Feeds this value into the given Hasher.

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

Feeds a slice of this type into the given Hasher.

impl PartialEq<Tag> for Tag

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

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

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

This method tests for !=.

impl StructuralEq for Tag

impl StructuralPartialEq for Tag