python多进程笔记

import multiprocessing
import datetime

def calc(i):
    sum =0
    for _ in range(1000000):
        sum +=1

if __name__ == "__main__":
    start =datetime.datetime.now()
    lst = []
    for i in range(10):
        p =multiprocessing.Process(target=calc,args=(i,),name="{}-{}".format(multiprocessing.current_process().name,i))
        p.start()
        lst.append(p)

    for i in lst:
        i.join()

    detail = (datetime.datetime.now() - start).total_seconds()
    print(detail)

---------------------------------------------------------------

import multiprocessing
import datetime

def calc(i):
    sum =0
    for _ in range(1000000):
        sum +=1

if __name__ == "__main__":
    start =datetime.datetime.now()
    pool = multiprocessing.Pool(5)

    for i in range(5):
        pool.apply_async(calc,args=(i,))

    pool.close()
    pool.join()
    detail = (datetime.datetime.now() - start).total_seconds()
    print(detail)

----------------------------------------------------------------

import threading
import multiprocessing
import time
from   concurrent import futures
import logging
FORMAT = "%(asctime)s %(thread)d %(message)s"
logging.basicConfig(level=logging.INFO,format=FORMAT)



def worker(i):
    sum =0
    time.sleep(1)
    logging.info("worker-{}".format(i))
    for _ in range(10000):
        sum +=1

exec =futures.ThreadPoolExecutor(max_workers=3)

fs = []

for i in range(3):
    f =exec.submit(worker,i)
    fs.append(f)

for i in range(3,6):
    f =exec.submit(worker,i)
    fs.append(f)

while True:
    time.sleep(2)
    logging.info(threading.enumerate())
    flag = True
    for f in fs:
        flag = flag and f.done()
    if flag:
        exec.shutdown()
        break
------------------------------------------

import threading
import multiprocessing
import time
from   concurrent import futures
import logging
FORMAT = "%(asctime)s %(thread)d %(message)s"
logging.basicConfig(level=logging.INFO,format=FORMAT)



def worker(i):
    sum =0
    time.sleep(1)
    logging.info("worker-{}".format(i))
    for _ in range(10000):
        sum +=1

if __name__ == "__main__":
    exec =futures.ProcessPoolExecutor(max_workers=3)

    fs = []

    for i in range(3):
        f =exec.submit(worker,i)
        fs.append(f)

    for i in range(3,6):
        f =exec.submit(worker,i)
        fs.append(f)

    while True:
        time.sleep(2)
        #logging.info(threading.enumerate())
        flag = True
        for f in fs:
            flag = flag and f.done()
        if flag:
            exec.shutdown()
            break
---------------------------------------------------

import threading
import multiprocessing
import time
from   concurrent import futures
import logging
FORMAT = "%(asctime)s %(thread)d %(message)s"
logging.basicConfig(level=logging.INFO,format=FORMAT)


def worker(i):
    sum =0
    time.sleep(1)
    logging.info("worker-{}".format(i))
    for _ in range(10000):
        sum +=1
    logging.info(multiprocessing.current_process().name)

if __name__ == "__main__":
    fs = []
    with futures.ProcessPoolExecutor(max_workers=4) as exec:
        for i in range(3):
           f = exec.submit(worker,i)
           fs.append(f)

        for i in range(3,6):
            f =exec.submit(worker,i)
            fs.append(f)

    while True:
        time.sleep(0.1)
        flag = True
        for f in fs:
            flag = flag and f.done()
        if flag:
            exec.shutdown()
            break