Method test_selector

Lib/test/test_selectors.py:338–389

(self)

            self.assertGreaterEqual(fd, 0)

    def test_selector(self):
        s = self.SELECTOR()
        self.addCleanup(s.close)

        NUM_SOCKETS = 12
        MSG = b" This is a test."
        MSG_LEN = len(MSG)
        readers = []
        writers = []
        r2w = {}
        w2r = {}

        for i in range(NUM_SOCKETS):
            rd, wr = self.make_socketpair()
            s.register(rd, selectors.EVENT_READ)
            s.register(wr, selectors.EVENT_WRITE)
            readers.append(rd)
            writers.append(wr)
            r2w[rd] = wr
            w2r[wr] = rd

        bufs = []

        while writers:
            ready = s.select()
            ready_writers = find_ready_matching(ready, selectors.EVENT_WRITE)
            if not ready_writers:
                self.fail("no sockets ready for writing")
            wr = random.choice(ready_writers)
            wr.send(MSG)

            for i in range(10):
                ready = s.select()
                ready_readers = find_ready_matching(ready,
                                                    selectors.EVENT_READ)
                if ready_readers:
                    break
                # there might be a delay between the write to the write end and
                # the read end is reported ready
                sleep(0.1)
            else:
                self.fail("no sockets ready for reading")
            self.assertEqual([w2r[wr]], ready_readers)
            rd = ready_readers[0]
            buf = rd.recv(MSG_LEN)
            self.assertEqual(len(buf), MSG_LEN)
            bufs.append(buf)
            s.unregister(r2w[rd])
            s.unregister(rd)
            writers.remove(r2w[rd])

        self.assertEqual(bufs, [MSG] * NUM_SOCKETS)

    @unittest.skipIf(sys.platform == 'win32',
                     'select.select() cannot be used with empty fd sets')