In Python for *nix, does
time.sleep() block the thread or the process?
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
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!