Jeremy Dunck Jeremy Dunck - 1 month ago 16
Python Question

time.sleep -- sleeps thread or process?

In Python for the *nix, does

time.sleep()
block the thread or the process?

Answer

It blocks the thread. If you look in Modules/timemodule.c in the Python source, you'll see that in the call to floatsleep(), the substantive part of the sleep operation is wrapped in a Py_BEGIN_ALLOW_THREADS and Py_END_ALLOW_THREADS block, allowing other threads to continue to execute while the current one sleeps. You can also test this with a simple python program:

import time
from threading import Thread

class worker(Thread):
    def run(self):
    	for x in xrange(0,11):
    		print x
    		time.sleep(1)

class waiter(Thread):
    def run(self):
    	for x in xrange(100,103):
    		print x
    		time.sleep(5)

def run():
    worker().start()
    waiter().start()

Which will print:

>>> thread_test.run()
0
100
>>> 1
2
3
4
5
101
6
7
8
9
10
102
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