flask執行緒池用法

1.執行緒池的用法

1. 在寫任務排程的時候，難免遇到使用多執行緒、多程序、執行緒池、程序池的場景 ，

from flask import Flask
from time import sleep
from concurrent.futures import ThreadPoolExecutor
# DOCS https://docs.python.org/3/library/concurrent.futures.html#concurrent.futures.ThreadPoolExecutor
executor = ThreadPoolExecutor(2)
app = Flask(__name__)
@app.route('/jobs')
def run_jobs():
 # 通過submit函式提交執行的函式到執行緒池中，submit函式立即返回，不阻塞
 executor.submit(long_task, 'hello', 123)
 return 'long task running.'

def long_task(arg1, arg2):
 print("args: %s %s!" % (arg1, arg2))
 sleep(5)
 print("Task is done!")

if __name__ == '__main__':
 app.run()
 

2.thread的用法

import time
from threading import Thread

def async_fun(f):

  def inner_fun(*args, **kwargs):

    t = Thread(target=f, args=args, kwargs=kwargs)

    t.start()

  return inner_fun


@async_fun

def test_a():

  time.sleep(10)

  print("test a run")


def test_b():

test_a()

  print("test b run")

test_b()
 

3.flask開啟多執行緒支援

1)threaded : 多執行緒支援，預設為False，即不開啟多執行緒;

app.run(threaded=True)

2)processes：程序數量，預設為1.

app.run(processes=True)

ps：多程序或多執行緒只能選擇一個，不能同時開啟

使用示例：

  app.run(host=myaddr,port=myport,debug=False,threaded=True) ### threaded開啟以後 不需要等佇列 threaded=True
    #或者
    #app.run(host=myaddr,port=myport,debug=False,processes=3) ### processes=N 程序數量，預設為1個
 

3.設定守護執行緒

import time
import threading

def test():
    while True:
        print threading.currentThread()
        time.sleep(1)

if __name__ == '__main__':
    t1 = threading.Thread(target=test)
    t1.setDaemon(True)  # python2.7設定
    t1.start()  
----------------------------------------------------------
# python 3.7實現
t1 = threading.Thread(target=ppp, args=(), daemon=True)
t1.start()

相關連結

https://www.cxyzjd.com/article/xiaoyu_wu/102820384

https://www.jb51.net/article/212169.htm

https://cloud.tencent.com/developer/article/1572261

https://www.cxyzjd.com/article/qq_33682575/105107041

https://python-parallel-programmning-cookbook.readthedocs.io/zh_CN/latest/chapter4/02_Using_the_concurrent.futures_Python_modules.html