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RuntimeSelector

fuel_dispatch::ranker::runtime_selector

Trait RuntimeSelector 

Source 
pub trait RuntimeSelector:
    Send
    + Sync
    + Debug {
    // Provided method
    fn select<'a>(&self, set: &'a AlternativeSet) -> Option<&'a Candidate> { ... }
}
Expand description

Dispatch-time selector over a plan’s per-node AlternativeSet. Phase 5.1 of the picker-work arc.

§Contract

  • select is called exactly once per kernel-bearing node, at dispatch time, by the executor’s resolve_compiled.
  • Implementors return None only when the set is empty — every non-empty set MUST have a pick. The default implementation (WinnerSelector) returns set.winner() (the first entry).
  • The selected Candidate’s kernel, caps, and backend become the executor’s dispatch parameters for that node.
  • Selectors are queried per-node and may make different picks for different nodes in the same realize — the trait carries no per-realize state.

§Sendness

Implementations must be Send + Sync so the executor can share a single selector across the compiler thread and the executor thread.

§Why not pass NodeId / OpKind / dtypes?

The Candidate already carries backend, precision, static_cost, and op_params; selectors that need op identity can derive it from these fields. If a future selector needs the graph-level NodeId or OpKind, we add a SelectorContext param — but Phase 5.1 keeps the surface minimal so the trait stays usable by selectors that only care about set contents.

Provided Methods§

Source

fn select<'a>(&self, set: &'a AlternativeSet) -> Option<&'a Candidate>

Pick one candidate from the set. None only when the set is empty; non-empty sets MUST produce a pick.

The default implementation returns set.winner() — the top-N’s first entry, which is Picker 1’s static-cost winner after rank+truncate.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§