cmeta.core_async module

CMeta asynchronous wrapper for the core class

cMeta author and developer: (C) 2025-2026 Grigori Fursin

See the cMeta COPYRIGHT and LICENSE files in the project root for details.

Classes

class cmeta.core_async.CMetaAsync(max_workers=None, logger=None, loop=None, **kwargs)

Bases: CMeta

Async wrapper around CMeta using multiprocessing for non-blocking operations.

This class extends CMeta to provide asynchronous wrappers around blocking operations using a ProcessPoolExecutor. It prevents blocking the event loop in FastAPI or other asyncio-based services by executing CMeta operations in separate worker processes.

Inherits all CMeta methods while providing async wrappers for blocking operations.

__init__(max_workers=None, logger=None, loop=None, **kwargs)

Initialize CMetaAsync with process pool executor.

Parameters:

• max_workers – Maximum number of worker processes in the pool.

• logger – Custom logger instance. If None, uses parent CMeta’s logger.

• loop – Event loop to use. If None, gets the current event loop.

• **kwargs – Additional keyword arguments passed to CMeta constructor.

Returns:

Operation result.

Return type:

dict

Raises:

Exception – Propagated runtime errors, if any.

async access(params)

Asynchronous non-blocking wrapper for CMeta.access().

Runs CMeta.access() in a worker process to avoid blocking the event loop.

Parameters:

params – Dictionary of parameters to pass to CMeta.access().

Returns:

Result dictionary from CMeta.access() with ‘return’ and other keys.

Return type:

dict

Raises:

Exception – Propagated runtime errors, if any.

access_sync(params)

Synchronous access using the inherited CMeta.access() method.

Use this method when already executing in a worker thread or process where blocking is acceptable.

Parameters:

params – Dictionary of parameters to pass to CMeta.access().

Returns:

Result dictionary from CMeta.access().

Return type:

dict

Raises:

Exception – Propagated runtime errors, if any.

shutdown()

Gracefully shutdown the process pool executor.

Waits for all pending tasks to complete before shutting down the executor. This method can be tied to FastAPI or other framework shutdown events.

Parameters:

None.

Returns:

Operation result.

Return type:

dict

Raises:

Exception – Propagated runtime errors, if any.