I want to run some function, foo, and get the return value, but only if it take less than T seconds to run the function. Otherwise I'll take None as an answer.
The specific use case that created this need for me, is in running a series of sympy nonlinear solvers, which often hang. In searching the help for sympy, devs recommended not trying to do that in sympy. But, I could not find a helpful implementation that solved this problem.
This is what I ended up doing. If you have a better solution, please share!
import threading
import time
# my function that I want to run with a timeout
def foo(val1, val2):
time.sleep(5)
return val1+val2
class RunWithTimeout(object):
def __init__(self, function, args):
self.function = function
self.args = args
self.answer = None
def worker(self):
self.answer = self.function(*self.args)
def run(self, timeout):
thread = threading.Thread(target=self.worker)
thread.start()
thread.join(timeout)
return self.answer
# this takes about 5 seconds to run before printing the answer (8)
n = RunWithTimeout(foo, (5,3))
print n.run(10)
# this takes about 1 second to run before yielding None
n = RunWithTimeout(foo, (5,3))
print n.run(1)
thread.join(timeout) instead of the while-loop?
thread.join() returns as soon as either the timeout ran out or thread dies (which happpens when it completed its work).