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Async-logger-close

Close the async logger queue and stop treating the logger as an active enqueue target. This API is the low-level lifecycle close primitive behind shutdown flows.

Interface

moonbit
pub fn[S] AsyncLogger::close(self : AsyncLogger[S], clear? : Bool = false) -> Unit {}

input

  • self : AsyncLogger[S] - Async logger that should be closed.
  • clear : Bool - Whether pending records should be abandoned immediately instead of being left for drain behavior.

output

  • Unit - No return value. The logger lifecycle state is updated in place.

Explanation

Detailed rules explaining key parameters and behaviors

  • close(...) marks the logger as closed immediately.
  • clear=false closes the queue without explicitly abandoning pending records in the helper itself.
  • clear=true counts pending records as dropped and resets pending_count to 0 before closing the queue.
  • This helper does not itself wait for the worker to finish.
  • close(...) also does not change has_failed() or last_error(); it is a closure primitive, not a failure reset API.
  • Because this is a low-level close primitive, it does not first run wait_idle() or apply the runtime-dependent fallback logic used by shutdown().
  • After closure, later log attempts do not add new pending or dropped counts, but backend behavior can still differ before the closed queue rejects the record.
  • In the current direct coverage, compatibility runtimes short-circuit before patch-path work on late log attempts, while native-worker runtimes may still build and patch the record before the closed queue rejects it.

How to Use

Here are some specific examples provided.

When Need Immediate Queue Closure

When teardown should stop normal enqueue activity right away:

moonbit
logger.close()

In this example, the logger enters closed state immediately.

When Need To Abandon Backlog Explicitly

When pending records should be discarded during fast shutdown:

moonbit
logger.close(clear=true)

In this example, queued backlog is counted as dropped instead of waiting for further drain.

Error Case

e.g.:

  • If clear=true, pending records are intentionally discarded and contribute to dropped_count().

  • If clear=false, pending records may still exist after closure until worker drain or later cleanup resolves them.

  • If callers perform late log attempts after closure, backlog counters still stay unchanged, but patch-path side effects are runtime-dependent and should not be treated as a portable post-close contract.

  • If callers need graceful waiting for drain completion, shutdown() is usually the better API.

Notes

  1. This is a low-level lifecycle helper; prefer shutdown() for normal graceful teardown.

  2. Use clear=true only when backlog loss is an acceptable shutdown tradeoff.

  3. Pair it with pending_count(), dropped_count(), or state() when you need to observe what happened to existing backlog after closure.

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