如何在 Python 中获取线程执行时间

Question

Hello I have a script that does a GET request and I need to measure the thread that is loaded with that function. This is the code that I have written but it doesn`t show the correct time it shows 0 and sometimes 0.001 or something like that.

import requests
import threading
import time

def functie():
    URL = "http://10.250.100.170:9082/SPVWS2/rest/listaMesaje"
    r = requests.get(url = URL)
    data = r.json()


threads = []
for i in range(5):
    start = time.clock_gettime_ns()
    t = threading.Thread(target=functie)
    threads.append(t)
    t.start()
    end = time.clock_gettime_ns()
    print(end-start)

I need an example on how to get in my code the exact thread execution time. Thanks

Answer 1

The code in this script runs on the main thread and you are trying to measure the timing of thread t. To do that, you can tell main thread to wait until thread t has finished like this:

import requests
import threading
import time

threads = []
start = []
end = []

def functie():
    start.append(time.clock_gettime_ns())

    URL = "http://10.250.100.170:9082/SPVWS2/rest/listaMesaje"
    r = requests.get(url = URL)
    data = r.json()

    end.append(time.clock_gettime_ns())

for i in range(5):
    start.append(time.clock_gettime_ns())
    t = threading.Thread(target=functie)
    threads.append(t)
    t.start()

for (i,t) in enumerate(threads):
    t.join()
    print(end[i]-start[i])

Answer 2

The other answer would produce incorrect results. If the first thread takes longer than the second, the time of the second will be recorded as the same as the first. This is because the end times are recorded sequentially after each join finishes rather than when the thread's target function actually finishes which may be in any order.

A better way would be to wrap the target functions of the threads with code that does this:

def thread_time(target):
   def wrapper(*args, **kwargs):
       st = time.time()
       try:
           return target(*args, **kwargs)
       finally:
           et = time.time()
           print(et - st)
           threading.currentThread().duration = et - st
   return wrapper

def functie():
    print "starting"
    time.sleep(1)
    print "ending"

t = threading.Thread(target=thread_time(functie))
t.start()
t.join()
print(t.duration)