Working with the multiprocessing¶

Overview¶

This is

Classifity the IO or CPU bond¶

Executing code in thread or process pools awaitable loop.run_in_executor(executor, func, *args) Arrange for func to be called in the specified executor.

The executor argument should be an concurrent.futures.Executor instance. The default executor is used if executor is None.

Example:

import asyncio import concurrent.futures

def blocking_io(): # File operations (such as logging) can block the # event loop: run them in a thread pool. with open('/dev/urandom', 'rb') as f: return f.read(100)

def cpu_bound(): # CPU-bound operations will block the event loop: # in general it is preferable to run them in a # process pool. return sum(i * i for i in range(10 ** 7))

async def main(): loop = asyncio.get_running_loop()

## Options:

# 1. Run in the default loop's executor:
result = await loop.run_in_executor(
    None, blocking_io)
print('default thread pool', result)

# 2. Run in a custom thread pool:
with concurrent.futures.ThreadPoolExecutor() as pool:
    result = await loop.run_in_executor(
        pool, blocking_io)
    print('custom thread pool', result)

# 3. Run in a custom process pool:
with concurrent.futures.ProcessPoolExecutor() as pool:
    result = await loop.run_in_executor(
        pool, cpu_bound)
    print('custom process pool', result)

if name == 'main': asyncio.run(main())