Trait scoped_gc::Trace

pub unsafe trait Trace {
    unsafe fn mark(&self);
    unsafe fn root(&self);
    unsafe fn unroot(&self);
}

Used to propagate signals across the objects graph of values managed by the garbage collector.

This trait is unsafe because an invalid implementations may cause dangling pointers. For example, if trace is not propagated to a reachable Gc pointers then its value may be freed. The next dereference of this Gc causes then an error.

You should never initiate the traversal of the object graph: it is the role of the library. Propagating a signal at the wrong time may cause an invalid state leading to dangling pointers.

Required methods

unsafe fn mark(&self)

Propagates the mark signal across the objects graph.

This signal is used during the first phase of garbage collection to mark the values that are still reachable.

The signal is initiated at the rooted values and propagated to reach the adjacent Gc pointers. If their value is not already marked they mark it and propagate the signal further in the graph.

unsafe fn root(&self)

Propagates the root signal across the objects graph.

This signal is used to signal that there is a new root pointing to a managed value. This prevents this value (and any other value reachable from it) from being collected.

This is initiated when creating a new Gc pointer or mutably borrowing the value inside a GcRefCell.

unsafe fn unroot(&self)

Propagates the unroot signal across the objects graph.

This signal is used to signal the destruction of a root pointing to a managed value. If this was the last root, the value is not longer used to initiate mark signals: if there are no other rooted values that can reach it, it becomes eligible for garbage collection.

This is initiated when a Gc pointer or mutably borrowing the value inside a GcRefCell.

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Implementations on Foreign Types

impl Trace for ()

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for bool

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for u8

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for u16

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for u32

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for u64

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for usize

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for i8

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for i16

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for i32

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for i64

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for isize

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for f32

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for f64

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for char

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for String

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for Path

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for PathBuf

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for AtomicBool

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for AtomicIsize

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl Trace for AtomicUsize

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl<T: Trace> Trace for Range<T>

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl<T: Trace> Trace for Box<T>

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl<T: Trace> Trace for Option<T>

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl<T: Trace, E: Trace> Trace for Result<T, E>

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl<T: Trace> Trace for Vec<T>

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl<K: Eq + Hash + Trace, V: Trace> Trace for HashMap<K, V>

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl<K: Eq + Ord + Trace, V: Trace> Trace for BTreeMap<K, V>

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

impl<'a> Trace for &'a str

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

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Implementors

impl<'gc, T: Trace> Trace for Gc<'gc, T>

unsafe fn mark(&self)

Marks the value in the GcBox as reachable.

The mark signal will be propagated further in the object graph unless the box was already marked (to avoid infinite loops on cycles, or redundant traversals).

unsafe fn root(&self)

Tags this Gc pointer as a root for its value.

unsafe fn unroot(&self)

Untags this Gc pointer as a root for its value.

impl<T: Trace> Trace for GcRefCell<T>

unsafe fn mark(&self)

unsafe fn root(&self)

unsafe fn unroot(&self)

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