gevent and thread performance compare?

Question

i write a test case to compare thread and gevent's performance,
using multithread to do a task like:

import time
import threading

def sync_task():
    #do something
    time.sleep(1)

def multi_thread_run():
    start = time.time()
    for i in range(10):
        t = threading.Thread(target=sync_task)
        t.start()
    end = time.time()
    print("multi thread task executed in %f second"%(end-start))

print:

multi thread task executed in 0.002425 second

however, using gevent replace thread do same task:

import gevent
def async_task():
    #do something
    gevent.sleep(1)

def async_run():
    start = time.time()
    coroutins = []

    for i in range(10):
        coroutins.append(gevent.spawn(async_task))
    gevent.joinall(coroutins)

    end = time.time()
    print("async task executed in %f second"%(end-start))

print:

async task executed in 1.002012 second

in many blog post I see coroutine is more effective than mutilthread, in this case, how to explain it?

Answer 1

That's because you didn't join your Thread - it means that program doesn't wait for thread to finish executing, and instead ends almost immediatelly.