需求

加入我們需要處理一串個位數（0~9），奇數時需要迴圈列印它；偶數則等待對應時長並完成所有任務；0則是錯誤，但不需要終止任務，可以自定義一些處理。

關鍵點

定義func函數處理需求

callback處理返回結果，只有偶數和0返回；奇數會一直執行；要控制線程池狀態，則需要針對偶數和0時拋出異常，並捕獲異常處理。

threadpool定義線程池併發

實現

# -*- coding: utf-8 -*-
from threadpool import makeRequests, ThreadPool
import time
from multiprocessing import Process

異常定義和特殊值（0）定義

class Finish(SyntaxWarning):
    pass

class PauseInfo(SyntaxWarning):
    pass


pause_num = 0

func函數定義

0時返回False，其他偶數返回True

def func(para):
    if para == pause_num:
        print('start for %d and wait %ds' % (para, 4))
        time.sleep(4)
        print('error bcs ',para)
        return False

    if para % 2 == 0:
        print('start for %d and wait %ds' % (para, para))
        time.sleep(para)
        print('stop for', para)
        return True

    while True:
        print('continue for', para)
        time.sleep(para)

callback定義

def callback(request, result):
    if result:
        raise Finish
    else:
        raise PauseInfo

線程池處理

Finish標識任務完成，再次誘發異常退出線程池處理；

def main_thread(paras):
    pool = ThreadPool(10)
    requests = makeRequests(callable_=func, args_list=paras, callback=callback)
    [pool.putRequest(req) for req in requests]
    while True:
        try:
            pool.wait()
        except Finish as e:
            raise SystemExit
        except PauseInfo as e:
            print('Pause bcs %d but will continue' % pause_num)
        except Exception as e:
            print('Unknown error so will quit')
            raise SystemExit

主函數起一個測試進程

if __name__ == '__main__':
    while True:
        s = input('Input number list to test and any other word to quit\n')
        paras = []
        for para in s:
            if para.isnumeric():
                paras.append(int(para))
            else:
                break

        try:
            thread_test = Process(target=main_thread, args=(paras,))
            thread_test.start()
            thread_test.join(timeout=20)
        except TimeoutError as e:
            print('task timeout')
        except Exception as e:
            print('unknow error:',e)

結果驗證

處理108，看列印可以看到，1被迴圈處理，0處理的時候報錯；8處理完畢則任務結束

Input number list to test and any other word to quit
108
continue for 1
start for 0 and wait 4s
start for 8 and wait 8s
continue for 1
continue for 1
continue for 1
error bcs  0
continue for 1
Pause bcs 0 but will continue
continue for 1
continue for 1
continue for 1
continue for 1
stop for 8
Input number list to test and any other word to quit