带多处理,池和读取文件的Control-C处理

时间:2020-05-23 17:31:08

标签: python multiprocessing pool

我刚刚开始使用Multiprocessing和Python,我需要一些帮助在程序中捕获Control-C。我正在制作的脚本将读取一个文件,然后在每一行上执行一些任务。在任何人对I / O和多处理的优点/缺点发表评论之前,我都知道:)这些任务使它们非常友好于多线程。

我有以下代码,并且从文档中,我希望它可以工作,但是它没有捕获我的键盘异常!哎呀...请帮忙

在Win10上运行是否有任何区别:

from multiprocessing import cpu_count
from multiprocessing.dummy import Pool as ThreadPool
import argparse
from time import sleep
import signal
import sys


def readfile(file):
  with open(file, 'r') as file:
    data = file.readlines()
    file.close()
  return data

def work(line):
  while(True):
    try:
      print(f"\rgoing to do some work on {line}")
      countdown(5)
    except (KeyboardInterrupt, SystemExit):
      print("Exiting...")
      break

def countdown(time=30):
  sleep(time)

def parseArgs(args):
  if args.verbose:
    verbose = True
    print("[+] Verbosity turned on")
  else:
    verbose = False
  if args.threads:
    threads = args.threads
  else:
    threads = cpu_count()
  print(f'[+] Using {threads} threads')
  return threads, verbose, args.file


if __name__ == '__main__':
  parser = argparse.ArgumentParser()
  parser.add_argument("-f", "--file", required = True, help="Insert the flie you plan on parsing")
  parser.add_argument("-t", "--threads", help="Number of threads, by default will use all available processors")
  parser.add_argument("-v", "--verbose", help="increase output verbosity",
                       action="store_true")
  threads, verbose, filename = parseArgs(parser.parse_args())
  #read the entire file and store it in a variable:
  data = readfile(filename)
  #Init the data pool
  pool = ThreadPool(threads) # Number of threads going to use
  try:
    pool.map(work,data) # This launches the workers at the function to do work
  except KeyboardInterrupt:
    print("Exiting...")
  finally:
    pool.close()
    pool.join()

1 个答案:

答案 0 :(得分:0)

在使用Control-C时,程序可能位于pool.join(),等待所有线程完成。 pool.map函数仅启动所有进程,但不会阻塞。这意味着在发生KeyboardInterrupt时,由于程序不在try块内,因此未捕获到它。

我不太了解这里的最佳做法,但我会尝试:

try: 
    pool.map(work, data) # This launches the workers at the function to do work 
    pool.close() 
    pool.join()
except KeyboardInterrupt: 
    print("Exiting...")