Struct ObjectArenaExhausted 

pub struct ObjectArenaExhausted {
    pub objects: usize,
}

The target refused to materialise a kernel object a mutex needs.

The defect this closes

A VxWorks pthread mutex has no kernel SEMAPHORE until its first lock: pthread_mutex_init only stamps the magic, and pthreadMutexInit calls semMCreate from inside pthread_mutex_lock. When that returns NULL the chain hands back 0x16 — EINVAL, not ENOMEM — and std::sync::Mutex turns it into “failed to lock mutex: invalid argument (os error 22)” and panics. Measured on target at 588 live semaphores with 49 sets / 98 workers / 48 connections; the panicking worker took its set with it.

It is not a total. Creation resumed past 1,024 objects after that NULL, so the arena is a transient refusal and a byte or count budget is the wrong shape for it — there is no per-thread figure to add to PER_THREAD_OBJECT_ARENA, and a cap set at 588 would refuse connections a moment later than the target would have served them. What a transient refusal needs is for the rate of creation to bend to the target, which is what this gate does: the pool asks for the object at a point where “no” costs one refusal, and the client’s retry is the pacing.

Why this is not its own AcquireError variant

It rides as the payload of AcquireError::SpawnFailed, whose meaning it shares exactly — the target said no, and the pool’s own bounds were never reached. A consumer that needs to tell an arena refusal from a stack refusal downcasts, so the discriminator is a type rather than the message prose that AcquireError exists to stop consumers parsing.

Fields

objects: usize

How many objects the set needed — one per worker.

Trait Implementations

impl Clone for ObjectArenaExhausted

fn clone(&self) -> ObjectArenaExhausted

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ObjectArenaExhausted

impl Debug for ObjectArenaExhausted

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

Formats the value using the given formatter.

impl Display for ObjectArenaExhausted

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

Formats the value using the given formatter.

impl Error for ObjectArenaExhausted

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.