NTHREAD = 1000
MAX_FD = 5
MAX_SLEEP = 1.0
FILENAME = __file__

import threading
import os
import random
import resource
import time

resource.setrlimit(resource.RLIMIT_NOFILE, (MAX_FD, MAX_FD))

def random_sleep():
    seconds = MAX_SLEEP * random.random()
    time.sleep(seconds)

def run_in_thread():
    try:
        fd = os.open(FILENAME, os.O_RDONLY)
    except OSError:
        pass
    else:
        random_sleep()
        os.close(fd)

threads = []
try:
    for i in range(NTHREAD):
        t = threading.Thread(target=run_in_thread)
        threads.append(t)
        t.start()

    for t in threads:
        t.join()

except Exception as e:
    print("Caught exception", e)