Python多进程开发之如何轻松突破GIL瓶颈

from multiprocessing import Process
import os

def worker():
    print('子进程PID:', os.getpid())

if __name__ == '__main__':
    p = Process(target=worker)
    p.start()
    p.join()
    print('主进程结束')

from multiprocessing import Process
import time

def task(name):
    print(f'{name} 开始')
    time.sleep(2)
    print(f'{name} 结束')

if __name__ == '__main__':
    proc_list = []
    for i in range(3):
        p = Process(target=task, args=(f'进程{i+1}',))
        p.start()
        proc_list.append(p)
    for p in proc_list:
        p.join()
    print('所有子进程结束')

import multiprocessing
import time

class ClockProcess(multiprocessing.Process):
    def __init__(self, interval):
        multiprocessing.Process.__init__(self)
        self.interval = interval

    def run(self):
        n = 5
        while n > 0:
            print("当前时间: {0}".format(time.ctime()))
            time.sleep(self.interval)
            n -= 1


if __name__ == '__main__':
    p = ClockProcess(3)
    p.start()

from multiprocessing import Pool
import os, time

def square(n):
    print('计算', n, '在进程', os.getpid())
    time.sleep(1)
    return n * n

if __name__ == '__main__':
    with Pool(processes=3) as pool:
        results = pool.map(square, range(5))
    print('返回结果:', results)

from multiprocessing import Process, Queue

def producer(q):
    for i in range(5):
        q.put(i)
    q.put(None)  # 发送结束标记

def consumer(q):
    while True:
        item = q.get()
        if item is None:
            break
        print('消费:', item)

if __name__ == '__main__':
    q = Queue()
    p1 = Process(target=producer, args=(q,))
    p2 = Process(target=consumer, args=(q,))
    p1.start()
    p2.start()
    p1.join()
    p2.join()

from multiprocessing import Process, Value, Array

def worker(val, arr):
    val.value += 10
    for i in range(len(arr)):
        arr[i] *= 2

if __name__ == '__main__':
    num = Value('i', 5)                # int类型共享变量
    arr = Array('i', [1, 2, 3, 4])     # 数组
    p = Process(target=worker, args=(num, arr))
    p.start()
    p.join()
    print('num =', num.value)
    print('arr =', list(arr))

from multiprocessing import Process, Lock, Value

def add(lock, counter):
    for _ in range(100000):
        with lock:
            counter.value += 1

if __name__ == '__main__':
    lock = Lock()
    counter = Value('i', 0)
    procs = [Process(target=add, args=(lock, counter)) for _ in range(4)]
    for p in procs:
        p.start()
    for p in procs:
        p.join()
    print('结果:', counter.value)