Kill several problems at once: test_poll() failed sometimes for me.

Turns out the mysterious "expected output" file contained exactly N dots,
because test_poll() has a loop that *usually* went around N times,
printing one dot on each loop trip.  But there's no guarantee of that,
because the exact value of N depended on the vagaries of scheduling
time.sleep()s across two different processes.  So stopped printing dots,
and got rid of the expected output file.  Add a loop counter instead,
and verify that the loop goes around at least a couple of times.  Also
cut the minimum time needed for this test from 4 seconds to 1.
This commit is contained in:
Tim Peters 2004-10-13 03:43:40 +00:00
parent 4052fe5a9b
commit 29b6b4f7c7
2 changed files with 11 additions and 8 deletions

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@ -1,2 +0,0 @@
test_subprocess
.........

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@ -350,11 +350,16 @@ class ProcessTestCase(unittest.TestCase):
def test_poll(self):
p = subprocess.Popen([sys.executable,
"-c", "import time; time.sleep(4)"])
while p.poll() == None:
sys.stdout.write(".")
sys.stdout.flush()
time.sleep(0.5)
"-c", "import time; time.sleep(1)"])
count = 0
while p.poll() is None:
time.sleep(0.1)
count += 1
# We expect that the poll loop probably went around about 10 times,
# but, based on system scheduling we can't control, it's possible
# poll() never returned None. It "should be" very rare that it
# didn't go around at least twice.
self.assert_(count >= 2)
# Subsequent invocations should just return the returncode
self.assertEqual(p.poll(), 0)