Concurrent programming process of the thread pool pool

Thread pool and process pool

Pool: represents a container. Thread pool is a thread storage containers, storage containers process pool is the process of

Why should the thread pool to store, process pool

1. Avoid frequent creation and destruction (processes, threads) to resource overhead
2. Can limit the number of threads exist to ensure that the server will not collapse because of a lack of resources
3. Help us manage the creation and destruction of threads
4. Manage the distribution of tasks

Process pool:

# 进程池
from concurrent.futures import ProcessPoolExecutor
from multiprocessing import Process
import os
import time

def task():
    time.sleep(0.1)
    print(os.getpid())


if __name__ == '__main__':
    pool = ProcessPoolExecutor(3)
    # 提交任务到池子中
    pool.submit(task)
    # time.sleep(1)
    pool.submit(task)

147332
147320

Thread Pool:

# 线程池
from concurrent.futures import ThreadPoolExecutor

from threading import  active_count,enumerate,currentThread
import os
import time

def task():
    print(currentThread().name)
# 创建线程池
pool = ThreadPoolExecutor(3)

# 提交任务到池子中
pool.submit(task)
pool.submit(task)

print(f"{enumerate()}")
print(f"{active_count()}")

ThreadPoolExecutor-0_0
ThreadPoolExecutor-0_0
[<_MainThread(MainThread, started 135020)>, <Thread(ThreadPoolExecutor-0_0, started daemon 134904)>, <Thread(ThreadPoolExecutor-0_1, started daemon 134872)>]
3

If the primary process does not end, pond inside the process or thread, also has been surviving