Struct Gate 

pub struct Gate { /* private fields */ }

Implementations

impl Gate

pub fn new(max_count: Option<usize>, acquire_timeout: Duration) -> Self

Create a new gate with optional max connections and acquire timeout.

• max_count: Maximum concurrent connections (None = no configured limit). The counter supports up to isize::MAX concurrent permits.
• acquire_timeout: How long to wait for a slot when at capacity

pub fn grace_period(&self) -> Option<Duration>

Returns the complete caller-declared grace period (None is indefinite).

pub fn count(&self) -> usize

Get the number of connections.

pub fn max_count(&self) -> Option<usize>

Admission capacity; None means unlimited.

pub fn force_shutdown(&self)

Trigger a forced (hard) shutdown. Wakes all waiters of wait_shutdown(). This is only called by wait_all_done() when the grace period elapses. External code should not call this directly.

pub fn graceful_shutdown(&self, duration: Option<Duration>)

Begin a graceful shutdown phase. Notifies graceful and records the optional grace period. This does not imply a forced/Hard shutdown signal.

None means indefinite grace period (critical tasks mode).

pub fn is_shutting_down(&self) -> bool

pub async fn wait_forced_shutdown(&self)

Wait for the forced (hard) shutdown signal. This does not fire for a clean drain. Private to this module; external code should use Permit::wait_forced_shutdown.

pub async fn wait_graceful_shutdown(&self)

pub async fn enter(&self) -> Result<Permit, Error>

Enter the gate, waiting up to the configured acquire timeout if the gate is currently at capacity.

Returns a Permit token. Dropping the permit leaves the gate.

pub fn try_enter(&self) -> Result<Permit, Error>

Try to enter the gate immediately without waiting for capacity.

This is where the limit is enforced, for both doors: enter waits and retries around this rather than testing the count itself.

pub async fn wait_all_done(&self) -> GateDrainOutcome

Wait until all permits are dropped, respecting the configured grace period. If the grace period elapses, this triggers force_shutdown() and reports the number of permits that remained when the hard signal was sent. Note: when returning via the forced path, count() may still be > 0 for a short time until connection tasks observe the hard signal and drop.

Call graceful_shutdown first

Before that signal this call does not return, even once the last permit is gone: all_done is a one-shot, and a permit released during ordinary operation would latch it permanently, so Permit::drop only fires it when graceful shutdown has already been asked for. Waiting without asking is therefore waiting for a signal nobody will send — which is also the right behaviour, since the grace-then-force path is only meaningful once the work has been told to wind down.

Trait Implementations

impl Clone for Gate

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Gate

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.