PoolExecutor

A concurrent.futures.Executor over a pymizu pool.

Usage

Source

PoolExecutor(
    pool,
    *,
    stop_pool=False,
)

submit() returns a real concurrent.futures.Future: wait / as_completed / result(timeout) / asyncio.wrap_future and the stdlib base Executor.map all work unchanged, so code written against ProcessPoolExecutor drops in. create() spawns an owned pool instead.

Parameters

pool: pymizu.Pool

The pool to wrap; its lifetime stays with its owner unless stop_pool is set — then shutdown() stops it.

stop_pool: bool = False

When True, shutdown() stops the wrapped pool.

Notes

Deltas from stdlib semantics: a task’s failure surfaces as pymizu.TaskError (the remote error envelope); Future.running() is always False (futures resolve at completion); cancellation is advisory, mirroring Task.cancel() — and shutdown(cancel_futures=True) cancels every outstanding future, since the pool exposes no queued-versus-running signal (a running task completes, but its result is discarded). An infrastructure failure (e.g. the wrapped pool is stopped from under the executor) fails every outstanding future; later submissions raise instead of queueing onto a broken executor. Resolution — including any add_done_callback callables — runs on the core’s listener thread, the same discipline as the stdlib executors’ management thread: keep callbacks short, and never block one on the pool itself. map is the stdlib base implementation over submit — for bulk maps, Pool.map is the faster path.

Examples

Use as a drop-in concurrent.futures.Executor:

import pymizu

with pymizu.PoolExecutor.create(2) as ex:
    futures = [ex.submit(pow, 2, i) for i in range(4)]
    results = [f.result() for f in futures]
results

[1, 2, 4, 8]

Methods

Name	Description
create()	Spawn an owned pool —
shutdown()	Stdlib shutdown.
submit()	Schedule fn(*args, **kwargs) on the pool.

create()

Spawn an owned pool —

Usage

Source

create(
    workers=1,
    **pool_kwargs,
)

Pool.create() with workers and pool_kwargs — and wrap it; shutdown() stops it.

Parameters

workers: int = 1

Number of worker processes for the pool.

pool_kwargs: _Any = {}

Forwarded to Pool.create().

Returns

A PoolExecutor wrapping the spawned pool.

shutdown()

Stdlib shutdown.

Usage

Source

shutdown(
    wait=True,
    *,
    cancel_futures=False,
)

Parameters

wait: bool = True

Wait for the outstanding futures.

cancel_futures: bool = False

Cancel the not-yet-started futures. Stops the pool only when stop_pool was set.

submit()

Schedule fn(*args, **kwargs) on the pool.

Usage

Source

submit(
    fn,
    /,
    *args,
    **kwargs,
)

Parameters

fn: _Callable[…, _Any]

The callable to run.

args: _Any = ()

Positional arguments for fn.

kwargs: _Any = {}

Keyword arguments for fn.

Returns

A concurrent.futures.Future resolving with the result.

Raises

RuntimeError

After shutdown.

pymizu.MizuError

The infrastructure failure that broke the executor (its drain failed every outstanding future on it).