Struct SupervisorBuilder 

pub struct SupervisorBuilder { /* private fields */ }

Configures and spawns a supervisor.

Setting	Default
restart_limit	5 restarts in 60s
base_restart_delay	1s
max_restart_delay	30s
restart_jitter	0.1
dead_tasks_threshold	disabled
stop_timeout	5s

Implementations

impl SupervisorBuilder

pub fn new() -> Self

A builder with the defaults listed above and no tasks.

pub fn with_task(self, name: &str, task: impl SupervisedTask) -> Self

Registers a task to start with the supervisor. A later call with the same name replaces the earlier task.

pub fn with_restart_limit(self, max_restarts: u32, window: Duration) -> Self

A task that would need more than max_restarts restarts within any window is declared Dead instead. max_restarts = 0 disables restarts. The backoff delay doubles with each restart inside the window, so a task that stays up longer than window starts again from base_restart_delay.

pub fn with_unlimited_restarts(self) -> Self

Never give up restarting a failing task. The window still drives the backoff delay.

pub fn with_base_restart_delay(self, delay: Duration) -> Self

Delay before the first restart in a window. Each further restart in the window doubles it.

pub fn with_max_restart_delay(self, delay: Duration) -> Self

Upper bound for the restart delay.

pub fn with_restart_jitter(self, fraction: f64) -> Self

Randomly shortens each restart delay by up to this fraction of itself (0.0..=1.0), so tasks that failed together do not restart in lockstep. 0.0 disables it.

pub fn with_dead_tasks_threshold(self, fraction: f64) -> Self

Shuts the supervisor down with TooManyDeadTasks once at least one task is dead and dead / total >= fraction. Killed tasks count as dead. fraction is clamped to 0.0..=1.0: 0.0 means “any dead task”, 1.0 means “every task”.

pub fn with_stop_timeout(self, timeout: Duration) -> Self

How long a cancelled run may keep going before its future is dropped. Applies to kill, restart and shutdown.

pub fn spawn(self) -> SupervisorHandle

Spawns the supervisor and every registered task.

Panics

Panics if called outside a Tokio runtime.

Trait Implementations

impl Default for SupervisorBuilder

fn default() -> Self

Returns the “default value” for a type.