time.sleep -- sleeps thread or process?
Solution 1
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
Solution 2
It will just sleep the thread except in the case where your application has only a single thread, in which case it will sleep the thread and effectively the process as well.
The python documentation on sleep()
doesn't specify this however, so I can certainly understand the confusion!
Solution 3
Just the thread.
Solution 4
The thread will block, but the process is still alive.
In a single threaded application, this means everything is blocked while you sleep. In a multithreaded application, only the thread you explicitly 'sleep' will block and the other threads still run within the process.
Solution 5
Only the thread unless your process has a single thread.
Jeremy Dunck
Updated on July 08, 2022Comments
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Jeremy Dunck almost 2 years
In Python for *nix, does
time.sleep()
block the thread or the process?