Struct Config 

pub(crate) struct Config {
    pub(crate) global_queue_interval: Option<u32>,
    pub(crate) event_interval: u32,
    pub(crate) before_park: Option<Arc<dyn Fn() + Send + Sync>>,
    pub(crate) after_unpark: Option<Arc<dyn Fn() + Send + Sync>>,
    pub(crate) before_spawn: Option<Arc<dyn Fn(&TaskMeta<'_>) + Send + Sync>>,
    pub(crate) after_termination: Option<Arc<dyn Fn(&TaskMeta<'_>) + Send + Sync>>,
    pub(crate) disable_lifo_slot: bool,
    pub(crate) seed_generator: RngSeedGenerator,
    pub(crate) metrics_poll_count_histogram: Option<HistogramBuilder>,
    pub(crate) enable_eager_driver_handoff: bool,
}

Fields

global_queue_interval: Option<u32>

How many ticks before pulling a task from the global/remote queue?

event_interval: u32

How many ticks before yielding to the driver for timer and I/O events?

before_park: Option<Arc<dyn Fn() + Send + Sync>>

Callback for a worker parking itself

after_unpark: Option<Arc<dyn Fn() + Send + Sync>>

Callback for a worker unparking itself

before_spawn: Option<Arc<dyn Fn(&TaskMeta<'_>) + Send + Sync>>

To run before each task is spawned.

after_termination: Option<Arc<dyn Fn(&TaskMeta<'_>) + Send + Sync>>

To run after each task is terminated.

disable_lifo_slot: bool

The multi-threaded scheduler includes a per-worker LIFO slot used to store the last scheduled task. This can improve certain usage patterns, especially message passing between tasks.

In Tokio versions before 1.51, tasks in the LIFO slot could not be stolen, which could cause issues in applications with long poll times. As a stop-gap, this unstable option lets users disable the LIFO task. Now that the LIFO slot is stealable, we may remove this option in a future version.

seed_generator: RngSeedGenerator

Random number generator seed to configure runtimes to act in a deterministic way.

metrics_poll_count_histogram: Option<HistogramBuilder>

How to build poll time histograms

enable_eager_driver_handoff: bool

If true, an idle worker is woken whenever a worker thread transitions from polling the I/O driver to polling its own tasks (requires tokio_unstable).