qlauncher.workflow.local_scheduler

qlauncher.workflow.local_scheduler#

Summary#

Classes:

LocalJobManager

Run jobs locally using a per-job child process.

MPTask

Public-facing wrapper around _InnerMPTask.

Functions:

get_timeout

Get timeout to wait on an event, useful when awaiting multiple tasks and total timeout must be max_timeout.

Reference#

qlauncher.workflow.local_scheduler.get_timeout(max_timeout: int | float | None, start: int | float) → float | None[source]#

Get timeout to wait on an event, useful when awaiting multiple tasks and total timeout must be max_timeout.

Parameters:

  • max_timeout (int | float | None) – Total allowed timeout, None = infinite wait.

  • start (int | float) – Await start timestamp (time.time())

Returns:

Remaining timeout or None if max_timeout was None

Return type:

int | float | None

class qlauncher.workflow.local_scheduler.MPTask(task: Callable, callbacks: list[Callable] | None = None)[source]#

Bases: object

Public-facing wrapper around _InnerMPTask.

This wrapper exists so that if the task object is garbage-collected, we best-effort cancel the underlying execution to avoid leaking subprocesses.

Parameters:

  • task (Callable) – Zero-argument callable to execute.

  • callbacks (list[Callable] | None) – Optional list of callables invoked with the task outcome.

_inner_task#

The underlying _InnerMPTask instance.

class qlauncher.workflow.local_scheduler.LocalJobManager(poll_interval_s: float = 0.05)[source]#

Bases: BaseJobManager

Run jobs locally using a per-job child process.

This manager implements the BaseJobManager interface and is primarily intended for local execution and testing (supports waiting for any job, cancellation, and cleanup).

submit(function: Callable, **kwargs) → str[source]#

Submit a function job to the scheduler.

Parameters:

  • function (Callable) – Function to be executed.

  • **kwargs – Manager-specific additional arguments (currently unused by LocalJobManager).

Returns:

Job ID as a string.

Return type:

str

wait_for_a_job(job_id: str | None = None, timeout: float | None = None) → str | None[source]#

Wait for a job to finish.

Parameters:

  • job_id (str | None) – If provided, wait for this specific job. If None, wait for any unfinished job.

  • timeout (float | None) – Maximum time to wait in seconds. If None, wait indefinitely.

Returns:

The finished job ID.

Raises:

  • KeyError – If job_id is provided but unknown.

  • ValueError – If waiting for any job but no jobs exist.

  • TimeoutError – If timeout expires before a job finishes.

Return type:

str | None

read_results(job_id: str) → Result[source]#

Read results for a finished job.

Parameters:

job_id (str) – Job ID.

Returns:

The job result.

Raises:

  • KeyError – If job_id is unknown.

  • BaseException – Re-raises an exception produced by the job.

Return type:

Result

cancel(job_id: str) → bool[source]#

Cancel a submitted job.

Parameters:

job_id (str) – Job ID.

Returns:

True if cancellation was performed (best-effort) and the job is marked finished.

Raises:

KeyError – If job_id is unknown.

Return type:

bool

clean_up() → None[source]#

Cancel all known jobs and mark them as finished.

Parameters:

None.

Returns:

None.

Return type:

None