#!/usr/bin/env python3.2
# -*- coding: UTF-8 -*-
"""
Tests if future.result(timeout) really waits too long.
DISCOVERED-IN: Backported library on MACOSX 10.6

PROBLEM:
future.result(timeout) waits at least until function is finished.
It raises a timeout only after the command execution has finished.
"""

from concurrent import futures
import time
import unittest

DELAYED_CALL_DURATION = 10

def delayed_call(duration=DELAYED_CALL_DURATION):
    print("delayed_call ...")
    time.sleep(duration)
    print("DONE.")
    return "Hello World."

def timed_call(f, *args):
    t0 = time.time()
    try:
        f(*args)
    except Exception as e:
        print("TIMED-CALL: Exception %s" % e)
    finally:
        pass
    return time.time() - t0

class FuturesMoreTest(unittest.TestCase):
    """
    OOPS:
    Waits longer than future.result(wait_duration) until call command has
    finished.
    """
    WAIT_DURATION = 2

    def setUp(self):
        if not hasattr(self, "executor"):
            self.executor = futures.ThreadPoolExecutor(max_workers=1)

    def do_future_wait(self, wait_duration):
        future = self.executor.submit(delayed_call)
        future.result(wait_duration)

    def test_result_with_timout_waitsUntilCommandHasFinished(self):
        duration = timed_call(self.do_future_wait, self.WAIT_DURATION)
        print("DURATION: %s (expected: %s)" % (duration, self.WAIT_DURATION))
        self.assertTrue(self.WAIT_DURATION < DELAYED_CALL_DURATION)
        self.assertAlmostEqual(self.WAIT_DURATION, duration, 1)

# -- AUTO-MAIN:
if __name__ == '__main__':
    unittest.main()