summaryrefslogtreecommitdiffstats
path: root/Lib/test/test_selectors.py
blob: 454c17be99953c788e7d745ef73c94de47cc7f0a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
import errno
import os
import random
import selectors
import signal
import socket
import sys
from test import support
from time import sleep
import unittest
import unittest.mock
from time import monotonic as time
try:
    import resource
except ImportError:
    resource = None


if hasattr(socket, 'socketpair'):
    socketpair = socket.socketpair
else:
    def socketpair(family=socket.AF_INET, type=socket.SOCK_STREAM, proto=0):
        with socket.socket(family, type, proto) as l:
            l.bind((support.HOST, 0))
            l.listen()
            c = socket.socket(family, type, proto)
            try:
                c.connect(l.getsockname())
                caddr = c.getsockname()
                while True:
                    a, addr = l.accept()
                    # check that we've got the correct client
                    if addr == caddr:
                        return c, a
                    a.close()
            except OSError:
                c.close()
                raise


def find_ready_matching(ready, flag):
    match = []
    for key, events in ready:
        if events & flag:
            match.append(key.fileobj)
    return match


class BaseSelectorTestCase(unittest.TestCase):

    def make_socketpair(self):
        rd, wr = socketpair()
        self.addCleanup(rd.close)
        self.addCleanup(wr.close)
        return rd, wr

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

        rd, wr = self.make_socketpair()

        key = s.register(rd, selectors.EVENT_READ, "data")
        self.assertIsInstance(key, selectors.SelectorKey)
        self.assertEqual(key.fileobj, rd)
        self.assertEqual(key.fd, rd.fileno())
        self.assertEqual(key.events, selectors.EVENT_READ)
        self.assertEqual(key.data, "data")

        # register an unknown event
        self.assertRaises(ValueError, s.register, 0, 999999)

        # register an invalid FD
        self.assertRaises(ValueError, s.register, -10, selectors.EVENT_READ)

        # register twice
        self.assertRaises(KeyError, s.register, rd, selectors.EVENT_READ)

        # register the same FD, but with a different object
        self.assertRaises(KeyError, s.register, rd.fileno(),
                          selectors.EVENT_READ)

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

        rd, wr = self.make_socketpair()

        s.register(rd, selectors.EVENT_READ)
        s.unregister(rd)

        # unregister an unknown file obj
        self.assertRaises(KeyError, s.unregister, 999999)

        # unregister twice
        self.assertRaises(KeyError, s.unregister, rd)

    def test_unregister_after_fd_close(self):
        s = self.SELECTOR()
        self.addCleanup(s.close)
        rd, wr = self.make_socketpair()
        r, w = rd.fileno(), wr.fileno()
        s.register(r, selectors.EVENT_READ)
        s.register(w, selectors.EVENT_WRITE)
        rd.close()
        wr.close()
        s.unregister(r)
        s.unregister(w)

    @unittest.skipUnless(os.name == 'posix', "requires posix")
    def test_unregister_after_fd_close_and_reuse(self):
        s = self.SELECTOR()
        self.addCleanup(s.close)
        rd, wr = self.make_socketpair()
        r, w = rd.fileno(), wr.fileno()
        s.register(r, selectors.EVENT_READ)
        s.register(w, selectors.EVENT_WRITE)
        rd2, wr2 = self.make_socketpair()
        rd.close()
        wr.close()
        os.dup2(rd2.fileno(), r)
        os.dup2(wr2.fileno(), w)
        self.addCleanup(os.close, r)
        self.addCleanup(os.close, w)
        s.unregister(r)
        s.unregister(w)

    def test_unregister_after_socket_close(self):
        s = self.SELECTOR()
        self.addCleanup(s.close)
        rd, wr = self.make_socketpair()
        s.register(rd, selectors.EVENT_READ)
        s.register(wr, selectors.EVENT_WRITE)
        rd.close()
        wr.close()
        s.unregister(rd)
        s.unregister(wr)

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

        rd, wr = self.make_socketpair()

        key = s.register(rd, selectors.EVENT_READ)

        # modify events
        key2 = s.modify(rd, selectors.EVENT_WRITE)
        self.assertNotEqual(key.events, key2.events)
        self.assertEqual(key2, s.get_key(rd))

        s.unregister(rd)

        # modify data
        d1 = object()
        d2 = object()

        key = s.register(rd, selectors.EVENT_READ, d1)
        key2 = s.modify(rd, selectors.EVENT_READ, d2)
        self.assertEqual(key.events, key2.events)
        self.assertNotEqual(key.data, key2.data)
        self.assertEqual(key2, s.get_key(rd))
        self.assertEqual(key2.data, d2)

        # modify unknown file obj
        self.assertRaises(KeyError, s.modify, 999999, selectors.EVENT_READ)

        # modify use a shortcut
        d3 = object()
        s.register = unittest.mock.Mock()
        s.unregister = unittest.mock.Mock()

        s.modify(rd, selectors.EVENT_READ, d3)
        self.assertFalse(s.register.called)
        self.assertFalse(s.unregister.called)

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

        mapping = s.get_map()
        rd, wr = self.make_socketpair()

        s.register(rd, selectors.EVENT_READ)
        s.register(wr, selectors.EVENT_WRITE)

        s.close()
        self.assertRaises(RuntimeError, s.get_key, rd)
        self.assertRaises(RuntimeError, s.get_key, wr)
        self.assertRaises(KeyError, mapping.__getitem__, rd)
        self.assertRaises(KeyError, mapping.__getitem__, wr)

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

        rd, wr = self.make_socketpair()

        key = s.register(rd, selectors.EVENT_READ, "data")
        self.assertEqual(key, s.get_key(rd))

        # unknown file obj
        self.assertRaises(KeyError, s.get_key, 999999)

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

        rd, wr = self.make_socketpair()

        keys = s.get_map()
        self.assertFalse(keys)
        self.assertEqual(len(keys), 0)
        self.assertEqual(list(keys), [])
        key = s.register(rd, selectors.EVENT_READ, "data")
        self.assertIn(rd, keys)
        self.assertEqual(key, keys[rd])
        self.assertEqual(len(keys), 1)
        self.assertEqual(list(keys), [rd.fileno()])
        self.assertEqual(list(keys.values()), [key])

        # unknown file obj
        with self.assertRaises(KeyError):
            keys[999999]

        # Read-only mapping
        with self.assertRaises(TypeError):
            del keys[rd]

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

        rd, wr = self.make_socketpair()

        s.register(rd, selectors.EVENT_READ)
        wr_key = s.register(wr, selectors.EVENT_WRITE)

        result = s.select()
        for key, events in result:
            self.assertTrue(isinstance(key, selectors.SelectorKey))
            self.assertTrue(events)
            self.assertFalse(events & ~(selectors.EVENT_READ |
                                        selectors.EVENT_WRITE))

        self.assertEqual([(wr_key, selectors.EVENT_WRITE)], result)

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

        rd, wr = self.make_socketpair()

        with s as sel:
            sel.register(rd, selectors.EVENT_READ)
            sel.register(wr, selectors.EVENT_WRITE)

        self.assertRaises(RuntimeError, s.get_key, rd)
        self.assertRaises(RuntimeError, s.get_key, wr)

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

        if hasattr(s, 'fileno'):
            fd = s.fileno()
            self.assertTrue(isinstance(fd, int))
            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')
    def test_empty_select(self):
        # Issue #23009: Make sure EpollSelector.select() works when no FD is
        # registered.
        s = self.SELECTOR()
        self.addCleanup(s.close)
        self.assertEqual(s.select(timeout=0), [])

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

        rd, wr = self.make_socketpair()

        s.register(wr, selectors.EVENT_WRITE)
        t = time()
        self.assertEqual(1, len(s.select(0)))
        self.assertEqual(1, len(s.select(-1)))
        self.assertLess(time() - t, 0.5)

        s.unregister(wr)
        s.register(rd, selectors.EVENT_READ)
        t = time()
        self.assertFalse(s.select(0))
        self.assertFalse(s.select(-1))
        self.assertLess(time() - t, 0.5)

        t0 = time()
        self.assertFalse(s.select(1))
        t1 = time()
        dt = t1 - t0
        # Tolerate 2.0 seconds for very slow buildbots
        self.assertTrue(0.8 <= dt <= 2.0, dt)

    @unittest.skipUnless(hasattr(signal, "alarm"),
                         "signal.alarm() required for this test")
    def test_select_interrupt_exc(self):
        s = self.SELECTOR()
        self.addCleanup(s.close)

        rd, wr = self.make_socketpair()

        class InterruptSelect(Exception):
            pass

        def handler(*args):
            raise InterruptSelect

        orig_alrm_handler = signal.signal(signal.SIGALRM, handler)
        self.addCleanup(signal.signal, signal.SIGALRM, orig_alrm_handler)
        self.addCleanup(signal.alarm, 0)

        signal.alarm(1)

        s.register(rd, selectors.EVENT_READ)
        t = time()
        # select() is interrupted by a signal which raises an exception
        with self.assertRaises(InterruptSelect):
            s.select(30)
        # select() was interrupted before the timeout of 30 seconds
        self.assertLess(time() - t, 5.0)

    @unittest.skipUnless(hasattr(signal, "alarm"),
                         "signal.alarm() required for this test")
    def test_select_interrupt_noraise(self):
        s = self.SELECTOR()
        self.addCleanup(s.close)

        rd, wr = self.make_socketpair()

        orig_alrm_handler = signal.signal(signal.SIGALRM, lambda *args: None)
        self.addCleanup(signal.signal, signal.SIGALRM, orig_alrm_handler)
        self.addCleanup(signal.alarm, 0)

        signal.alarm(1)

        s.register(rd, selectors.EVENT_READ)
        t = time()
        # select() is interrupted by a signal, but the signal handler doesn't
        # raise an exception, so select() should by retries with a recomputed
        # timeout
        self.assertFalse(s.select(1.5))
        self.assertGreaterEqual(time() - t, 1.0)


class ScalableSelectorMixIn:

    # see issue #18963 for why it's skipped on older OS X versions
    @support.requires_mac_ver(10, 5)
    @unittest.skipUnless(resource, "Test needs resource module")
    def test_above_fd_setsize(self):
        # A scalable implementation should have no problem with more than
        # FD_SETSIZE file descriptors. Since we don't know the value, we just
        # try to set the soft RLIMIT_NOFILE to the hard RLIMIT_NOFILE ceiling.
        soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
        try:
            resource.setrlimit(resource.RLIMIT_NOFILE, (hard, hard))
            self.addCleanup(resource.setrlimit, resource.RLIMIT_NOFILE,
                            (soft, hard))
            NUM_FDS = min(hard, 2**16)
        except (OSError, ValueError):
            NUM_FDS = soft

        # guard for already allocated FDs (stdin, stdout...)
        NUM_FDS -= 32

        s = self.SELECTOR()
        self.addCleanup(s.close)

        for i in range(NUM_FDS // 2):
            try:
                rd, wr = self.make_socketpair()
            except OSError:
                # too many FDs, skip - note that we should only catch EMFILE
                # here, but apparently *BSD and Solaris can fail upon connect()
                # or bind() with EADDRNOTAVAIL, so let's be safe
                self.skipTest("FD limit reached")

            try:
                s.register(rd, selectors.EVENT_READ)
                s.register(wr, selectors.EVENT_WRITE)
            except OSError as e:
                if e.errno == errno.ENOSPC:
                    # this can be raised by epoll if we go over
                    # fs.epoll.max_user_watches sysctl
                    self.skipTest("FD limit reached")
                raise

        self.assertEqual(NUM_FDS // 2, len(s.select()))


class DefaultSelectorTestCase(BaseSelectorTestCase):

    SELECTOR = selectors.DefaultSelector


class SelectSelectorTestCase(BaseSelectorTestCase):

    SELECTOR = selectors.SelectSelector


@unittest.skipUnless(hasattr(selectors, 'PollSelector'),
                     "Test needs selectors.PollSelector")
class PollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):

    SELECTOR = getattr(selectors, 'PollSelector', None)


@unittest.skipUnless(hasattr(selectors, 'EpollSelector'),
                     "Test needs selectors.EpollSelector")
class EpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):

    SELECTOR = getattr(selectors, 'EpollSelector', None)


@unittest.skipUnless(hasattr(selectors, 'KqueueSelector'),
                     "Test needs selectors.KqueueSelector)")
class KqueueSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):

    SELECTOR = getattr(selectors, 'KqueueSelector', None)


@unittest.skipUnless(hasattr(selectors, 'DevpollSelector'),
                     "Test needs selectors.DevpollSelector")
class DevpollSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn):

    SELECTOR = getattr(selectors, 'DevpollSelector', None)



def test_main():
    tests = [DefaultSelectorTestCase, SelectSelectorTestCase,
             PollSelectorTestCase, EpollSelectorTestCase,
             KqueueSelectorTestCase, DevpollSelectorTestCase]
    support.run_unittest(*tests)
    support.reap_children()


if __name__ == "__main__":
    test_main()