prefect.concurrency.asyncio

ConcurrencySlotAcquisitionError

Bases: Exception

Raised when an unhandlable occurs while acquiring concurrency slots.

Source code in prefect/concurrency/asyncio.py

class ConcurrencySlotAcquisitionError(Exception):
    """Raised when an unhandlable occurs while acquiring concurrency slots."""

rate_limit async

Block execution until an occupy number of slots of the concurrency limits given in names are acquired. Requires that all given concurrency limits have a slot decay.

Parameters:

Name	Type	Description	Default
names	Union[str, List[str]]	The names of the concurrency limits to acquire slots from.	required
occupy	int	The number of slots to acquire and hold from each limit.	1

Source code in prefect/concurrency/asyncio.py

async def rate_limit(names: Union[str, List[str]], occupy: int = 1):
    """Block execution until an `occupy` number of slots of the concurrency
    limits given in `names` are acquired. Requires that all given concurrency
    limits have a slot decay.

    Args:
        names: The names of the concurrency limits to acquire slots from.
        occupy: The number of slots to acquire and hold from each limit.
    """
    names = names if isinstance(names, list) else [names]
    limits = await _acquire_concurrency_slots(names, occupy, mode="rate_limit")
    _emit_concurrency_acquisition_events(limits, occupy)