Struct ObserverLease 

pub struct ObserverLease { /* private fields */ }

RAII observer handle on a FillSession. One is minted for the pull owner and one per attached serve leg (FillRegistry::claim). Releasing it decrements the session’s observer count; the last-out release, if the pull is still running, cancels the pull so a fill no client is waiting on stops ingesting (#1610) — and hands back the session’s parked pull-thread handle so THAT caller joins it off-task (the owner-join hand-off: whoever leaves LAST joins the pull, freeing an owner whose own client finished first).

The decrement + cancel decision runs UNDER the registry map lock — the same lock claim/register_fill hold when they attach an observer. That mutual exclusion closes the resurrection race: a concurrent claim cannot fetch_add a session 0→1 in the window between this drop’s last-out fetch_sub (1→0) and its cancel(), so no live observer can end up bound to a cancelled fill. The lease therefore holds a Weak back to the registry (plus the session’s hash) to reach that lock at drop. If the upgrade fails the registry is gone, so the fill is moot and the drop just skips. It only TAKES the pull handle under the lock; the JOIN always runs off it.

Implementations

impl ObserverLease

pub fn release(self) -> Option<JoinHandle<()>>

Release the lease at a serve leg’s teardown, handing back the parked pull-thread handle when THIS release is the last one out. The caller joins that handle OFF the registry map lock and off its accept task (on a blocking thread). A non-last-out release returns None, so an owner whose own client finished first returns at once, leaving the pull filling for the remaining observers — the last of which cancels it (#1610 preserved). Named so teardown reads as intent rather than an incidental drop.

Trait Implementations

impl Debug for ObserverLease

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

Formats the value using the given formatter.

impl Drop for ObserverLease

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.