# asyncio_executor_process.py

import asyncio
import concurrent.futures
import logging
import sys
import time

def blocks(n):
    log = logging.getLogger('blocks({})'.format(n))
    log.info('running')
    time.sleep(0.1)
    log.info('done')
    return n ** 2


async def run_blocking_tasks(executor):
    log = logging.getLogger('run_blocking_tasks')
    log.info('starting')

    log.info('creating executor tasks')
    loop = asyncio.get_event_loop()
    blocking_tasks = [
        loop.run_in_executor(executor, blocks, i)
        for i in range(6)
    ]
    log.info('waiting for executor tasks')
    completed, pending = await asyncio.wait(blocking_tasks)
    results = [t.result() for t in completed]
    log.info('results: {!r}'.format(results))

    log.info('exiting')

# Configure logging to show the name of the thread where the log message originates
logging.basicConfig(
    level=logging.INFO,
    format='PID %(process)5s %(name)18s: %(message)s',
    stream=sys.stderr,
)


# Create a limited thread pool.
executor = concurrent.futures.ProcessPoolExecutor(max_workers=3)

event_loop = asyncio.get_event_loop()
try:
    event_loop.run_until_complete(
        run_blocking_tasks(executor)
    )
finally:
    event_loop.close()