> ## Documentation Index
> Fetch the complete documentation index at: https://docs.prefect.io/llms.txt
> Use this file to discover all available pages before exploring further.

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# sync

# `prefect.concurrency.v1.sync`

## Functions

### `concurrency` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/concurrency/v1/sync.py#L19" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={null}
concurrency(names: Union[str, list[str]], task_run_id: UUID, timeout_seconds: Optional[float] = None) -> Generator[None, None, None]
```

A context manager that acquires and releases concurrency slots from the
given concurrency limits.

**Args:**

* `names`: The names of the concurrency limits to acquire.
* `task_run_id`: The task run ID acquiring the limits.
* `timeout_seconds`: The number of seconds to wait to acquire the limits before
  raising a `TimeoutError`. A timeout of `None` will wait indefinitely.

**Raises:**

* `TimeoutError`: If the limits are not acquired within the given timeout.

Example:
A simple example of using the sync `concurrency` context manager:

```python  theme={null}
from prefect.concurrency.v1.sync import concurrency

def resource_heavy():
    with concurrency("test"):
        print("Resource heavy task")

def main():
    resource_heavy()
```


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