asyncio-taskpool/README.md

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# asyncio-taskpool
**Dynamically manage pools of asyncio tasks**
## Contents
- [Contents](#contents)
- [Summary](#summary)
- [Usage](#usage)
- [Installation](#installation)
- [Dependencies](#dependencies)
- [Testing](#testing)
- [License](#license)
## Summary
A **task pool** is an object with a simple interface for aggregating and dynamically managing asynchronous tasks.
With an interface that is intentionally similar to the [`multiprocessing.Pool`](https://docs.python.org/3/library/multiprocessing.html#module-multiprocessing.pool) class from the standard library, the `TaskPool` provides you such methods as `apply`, `map`, and `starmap` to execute coroutines concurrently as [`asyncio.Task`](https://docs.python.org/3/library/asyncio-task.html#task-object) objects. There is no limitation imposed on what kind of tasks can be run or in what combination, when new ones can be added, or when they can be cancelled.
For a more streamlined use-case, the `SimpleTaskPool` provides an even more intuitive and simple interface at the cost of flexibility.
If you need control over a task pool at runtime, you can launch an asynchronous `ControlServer` to be able to interface with the pool from an outside process or via a network, and stop/start tasks within the pool as you wish.
## Usage
Generally speaking, a task is added to a pool by providing it with a coroutine function reference as well as the arguments for that function. Here is what that could look like in the most simplified form:
```python
from asyncio_taskpool import SimpleTaskPool
...
async def work(_foo, _bar): ...
...
async def main():
pool = SimpleTaskPool(work, args=('xyz', 420))
await pool.start(5)
...
pool.stop(3)
...
pool.lock()
await pool.gather_and_close()
...
```
Since one of the main goals of `asyncio-taskpool` is to be able to start/stop tasks dynamically or "on-the-fly", _most_ of the associated methods are non-blocking _most_ of the time. A notable exception is the `gather_and_close` method for awaiting the return of all tasks in the pool. (It is essentially a glorified wrapper around the [`asyncio.gather`](https://docs.python.org/3/library/asyncio-task.html#asyncio.gather) function.)
For working and fully documented demo scripts see [USAGE.md](usage/USAGE.md).
## Installation
```shell
pip install asyncio-taskpool
```
## Dependencies
Python Version 3.8+, tested on Linux
## Testing
Install `asyncio-taskpool[dev]` dependencies or just manually install [`coverage`](https://coverage.readthedocs.io/en/latest/) with `pip`.
Execute the [`./coverage.sh`](coverage.sh) shell script to run all unit tests and receive the coverage report.
## License
`asyncio-taskpool` is licensed under the **GNU LGPL version 3.0** specifically.
The full license texts for the [GNU GPLv3.0](COPYING) and the [GNU LGPLv3.0](COPYING.LESSER) are included in this repository. If not, see https://www.gnu.org/licenses/.
---
© 2022 Daniil Fajnberg