Struct QuiesceTimeout 

pub struct QuiesceTimeout {
    pub remaining_cross_queue: u64,
    pub remaining_outstanding_refs: u64,
    pub elapsed: Duration,
}

Returned by Runtime::shutdown_quiesce when the timeout elapses before the executor reaches a quiesced state.

The diagnostic fields help identify which producer didn’t release its refs:

• remaining_cross_queue: number of cross-thread queue entries still pending at the moment of timeout. Non-zero indicates a producer thread is still pushing wakes faster than quiesce can drain them, OR a final-drain wake landed after the last drain pass — investigate which off-thread producer is still active.
• remaining_outstanding_refs: number of tasks still in Executor::all_tasks at the moment of timeout. Each represents a task with outstanding cross-thread refs (or a held JoinHandle).
• elapsed: how long quiesce ran before timing out.

PR 2 §2.4 open-item 5 noted that finer-grained diagnostics (“which task ID had the outstanding ref”) could be added if implementation revealed them as cheap to surface. The implementation uses Executor::task_count() which doesn’t enumerate tasks; adding per-task data here would require new accessors. Out of scope for initial PR 2; future enhancement.

Fields

remaining_cross_queue: u64

Number of cross-thread queue entries still pending at timeout. Non-zero means a producer is racing the drain loop.

remaining_outstanding_refs: u64

Number of tasks still alive at the moment of timeout. Each is a candidate for “producer hasn’t released its refs.”

elapsed: Duration

Time elapsed inside shutdown_quiesce before returning timeout. Approximately equal to the input timeout.

Trait Implementations

impl Debug for QuiesceTimeout

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

Formats the value using the given formatter.

impl Display for QuiesceTimeout

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

Formats the value using the given formatter.

impl Error for QuiesceTimeout

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

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

Provides type-based access to context intended for error reports.