Trait Policy 

pub trait Policy: Sized {
    // Required method
    fn handle(overflow: &mut VecDeque<Self>, message: Self) -> bool;
}

Overflow behavior for actor messages when an inbox is full.

Required Methods

fn handle(overflow: &mut VecDeque<Self>, message: Self) -> bool

Handle message when it cannot enter the bounded ready queue immediately.

Messages already in the ready queue are not provided here. Policy changes only apply to overflow retained beyond ready capacity. Policies may append, remove, replace, reorder, or clear overflow, and are responsible for bounding it when a hard memory limit is required.

The returned value is feedback for this enqueue attempt after the policy has made any overflow changes. Return true to report Feedback::Backoff or false to report Feedback::Dropped.

Warning

Do not enqueue into the same mailbox from this method or from destructors triggered by editing overflow. This method runs while the mailbox holds its overflow lock, so same mailbox re-entry can deadlock.

This method should not unwind after mutating overflow. A panic, including one from a destructor triggered while editing overflow, can leave retained overflow data stranded in the mailbox.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors