# Test case for the os.poll() function
import os
import subprocess
import random
import select
import threading
import time
import unittest
from test.support import TESTFN, run_unittest, reap_threads, cpython_only
try:
select.poll
except AttributeError:
raise unittest.SkipTest("select.poll not defined")
def find_ready_matching(ready, flag):
match = []
for fd, mode in ready:
if mode & flag:
match.append(fd)
return match
class PollTests(unittest.TestCase):
def test_poll1(self):
# Basic functional test of poll object
# Create a bunch of pipe and test that poll works with them.
p = select.poll()
NUM_PIPES = 12
MSG = b" This is a test."
MSG_LEN = len(MSG)
readers = []
writers = []
r2w = {}
w2r = {}
for i in range(NUM_PIPES):
rd, wr = os.pipe()
p.register(rd)
p.modify(rd, select.POLLIN)
p.register(wr, select.POLLOUT)
readers.append(rd)
writers.append(wr)
r2w[rd] = wr
w2r[wr] = rd
bufs = []
while writers:
ready = p.poll()
ready_writers = find_ready_matching(ready, select.POLLOUT)
if not ready_writers:
raise RuntimeError("no pipes ready for writing")
wr = random.choice(ready_writers)
os.write(wr, MSG)
ready = p.poll()
ready_readers = find_ready_matching(ready, select.POLLIN)
if not ready_readers:
raise RuntimeError("no pipes ready for reading")
rd = random.choice(ready_readers)
buf = os.read(rd, MSG_LEN)
self.assertEqual(len(buf), MSG_LEN)
bufs.append(buf)
os.close(r2w[rd]) ; os.close( rd )
p.unregister( r2w[rd] )
p.unregister( rd )
writers.remove(r2w[rd])
self.assertEqual(bufs, [MSG] * NUM_PIPES)
def test_poll_unit_tests(self):
# returns NVAL for invalid file descriptor
FD, w = os.pipe()
os.close(FD)
os.close(w)
p = select.poll()
p.register(FD)
r = p.poll()
self.assertEqual(r[0], (FD, select.POLLNVAL))
with open(TESTFN, 'w') as f:
fd = f.fileno()
p = select.poll()
p.register(f)
r = p.poll()
self.assertEqual(r[0][0], fd)
r = p.poll()
self.assertEqual(r[0], (fd, select.POLLNVAL))
os.unlink(TESTFN)
# type error for invalid arguments
p = select.poll()
self.assertRaises(TypeError, p.register, p)
self.assertRaises(TypeError, p.unregister, p)
# can't unregister non-existent object
p = select.poll()
self.assertRaises(KeyError, p.unregister, 3)
# Test error cases
pollster = select.poll()
class Nope:
pass
class Almost:
def fileno(self):
return 'fileno'
self.assertRaises(TypeError, pollster.register, Nope(), 0)
self.assertRaises(TypeError, pollster.register, Almost(), 0)
# Another test case for poll(). This is copied from the test case for
# select(), modified to use poll() instead.
def test_poll2(self):
cmd = 'for i in 0 1 2 3 4 5 6 7 8 9; do echo testing...; sleep 1; done'
proc = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE,
bufsize=0)
proc.__enter__()
self.addCleanup(proc.__exit__, None, None, None)
p = proc.stdout
pollster = select.poll()
pollster.register( p, select.POLLIN )
for tout in (0, 1000, 2000, 4000, 8000, 16000) + (-1,)*10:
fdlist = pollster.poll(tout)
if (fdlist == []):
continue
fd, flags = fdlist[0]
if flags & select.POLLHUP:
line = p.readline()
if line != b"":
self.fail('error: pipe seems to be closed, but still returns data')
continue
elif flags & select.POLLIN:
line = p.readline()
if not line:
break
self.assertEqual(line, b'testing...\n')
continue
else:
self.fail('Unexpected return value from select.poll: %s' % fdlist)
def test_poll3(self):
# test int overflow
pollster = select.poll()
pollster.register(1)
self.assertRaises(OverflowError, pollster.poll, 1 << 64)
x = 2 + 3
if x != 5:
self.fail('Overflow must have occurred')
# Issues #15989, #17919
self.assertRaises(ValueError, pollster.register, 0, -1)
self.assertRaises(OverflowError, pollster.register, 0, 1 << 64)
self.assertRaises(ValueError, pollster.modify, 1, -1)
self.assertRaises(OverflowError, pollster.modify, 1, 1 << 64)
@cpython_only
def test_poll_c_limits(self):
from _testcapi import USHRT_MAX, INT_MAX, UINT_MAX
pollster = select.poll()
pollster.register(1)
# Issues #15989, #17919
self.assertRaises(OverflowError, pollster.register, 0, USHRT_MAX + 1)
self.assertRaises(OverflowError, pollster.modify, 1, USHRT_MAX + 1)
self.assertRaises(OverflowError, pollster.poll, INT_MAX + 1)
self.assertRaises(OverflowError, pollster.poll, UINT_MAX + 1)
@reap_threads
def test_threaded_poll(self):
r, w = os.pipe()
self.addCleanup(os.close, r)
self.addCleanup(os.close, w)
rfds = []
for i in range(10):
fd = os.dup(r)
self.addCleanup(os.close, fd)
rfds.append(fd)
pollster = select.poll()
for fd in rfds:
pollster.register(fd, select.POLLIN)
t = threading.Thread(target=pollster.poll)
t.start()
try:
time.sleep(0.5)
# trigger ufds array reallocation
for fd in rfds:
pollster.unregister(fd)
pollster.register(w, select.POLLOUT)
self.assertRaises(RuntimeError, pollster.poll)
finally:
# and make the call to poll() from the thread return
os.write(w, b'spam')
t.join()
@unittest.skipUnless(threading, 'Threading required for this test.')
@reap_threads
def test_poll_blocks_with_negative_ms(self):
for timeout_ms in [None, -1000, -1, -1.0, -0.1, -1e-100]:
# Create two file descriptors. This will be used to unlock
# the blocking call to poll.poll inside the thread
r, w = os.pipe()
pollster = select.poll()
pollster.register(r, select.POLLIN)
poll_thread = threading.Thread(target=pollster.poll, args=(timeout_ms,))
poll_thread.start()
poll_thread.join(timeout=0.1)
self.assertTrue(poll_thread.is_alive())
# Write to the pipe so pollster.poll unblocks and the thread ends.
os.write(w, b'spam')
poll_thread.join()
self.assertFalse(poll_thread.is_alive())
os.close(r)
os.close(w)
def test_main():
run_unittest(PollTests)
if __name__ == '__main__':
test_main()