summaryrefslogtreecommitdiff
path: root/src/test/test-barrier.c
blob: ac9dd04b991f6d585e325ae28710f2605e6ca1ee (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
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  This file is part of systemd.

  Copyright 2014 David Herrmann <dh.herrmann@gmail.com>

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

/*
 * IPC barrier tests
 * These tests verify the correct behavior of the IPC Barrier implementation.
 * Note that the tests use alarm-timers to verify dead-locks and timeouts. These
 * might not work on slow machines where 20ms are too short to perform specific
 * operations (though, very unlikely). In case that turns out true, we have to
 * increase it at the slightly cost of lengthen test-duration on other machines.
 */

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <unistd.h>

#include "barrier.h"
#include "def.h"
#include "util.h"

/* 20ms to test deadlocks; All timings use multiples of this constant as
 * alarm/sleep timers. If this timeout is too small for slow machines to perform
 * the requested operations, we have to increase it. On an i7 this works fine
 * with 1ms base-time, so 20ms should be just fine for everyone. */
#define BASE_TIME (20 * USEC_PER_MSEC)

static void set_alarm(usec_t usecs) {
        struct itimerval v = { };

        timeval_store(&v.it_value, usecs);
        assert_se(setitimer(ITIMER_REAL, &v, NULL) >= 0);
}

static void sleep_for(usec_t usecs) {
        /* stupid usleep() might fail if >1000000 */
        assert_se(usecs < USEC_PER_SEC);
        usleep(usecs);
}

#define TEST_BARRIER(_FUNCTION, _CHILD_CODE, _WAIT_CHILD, _PARENT_CODE, _WAIT_PARENT)  \
        static void _FUNCTION(void) {                                   \
                Barrier b = BARRIER_NULL;                               \
                pid_t pid1, pid2;                                       \
                                                                        \
                assert_se(barrier_create(&b) >= 0);                     \
                                                                        \
                pid1 = fork();                                          \
                assert_se(pid1 >= 0);                                   \
                if (pid1 == 0) {                                        \
                        barrier_set_role(&b, BARRIER_CHILD);            \
                        { _CHILD_CODE; }                                \
                        exit(42);                                       \
                }                                                       \
                                                                        \
                pid2 = fork();                                          \
                assert_se(pid2 >= 0);                                   \
                if (pid2 == 0) {                                        \
                        barrier_set_role(&b, BARRIER_PARENT);           \
                        { _PARENT_CODE; }                               \
                        exit(42);                                       \
                }                                                       \
                                                                        \
                barrier_destroy(&b);                                    \
                set_alarm(999999);                                      \
                { _WAIT_CHILD; }                                        \
                { _WAIT_PARENT; }                                       \
                set_alarm(0);                                           \
        }

#define TEST_BARRIER_WAIT_SUCCESS(_pid) \
                ({                                                      \
                        int pidr, status;                               \
                        pidr = waitpid(_pid, &status, 0);               \
                        assert_se(pidr == _pid);                        \
                        assert_se(WIFEXITED(status));                   \
                        assert_se(WEXITSTATUS(status) == 42);           \
                })

#define TEST_BARRIER_WAIT_ALARM(_pid) \
                ({                                                      \
                        int pidr, status;                               \
                        pidr = waitpid(_pid, &status, 0);               \
                        assert_se(pidr == _pid);                        \
                        assert_se(WIFSIGNALED(status));                 \
                        assert_se(WTERMSIG(status) == SIGALRM);         \
                })

/*
 * Test basic sync points
 * This places a barrier in both processes and waits synchronously for them.
 * The timeout makes sure the sync works as expected. The sleep_for() on one side
 * makes sure the exit of the parent does not overwrite previous barriers. Due
 * to the sleep_for(), we know that the parent already exited, thus there's a
 * pending HUP on the pipe. However, the barrier_sync() prefers reads on the
 * eventfd, thus we can safely wait on the barrier.
 */
TEST_BARRIER(test_barrier_sync,
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_place(&b));
                sleep_for(BASE_TIME * 2);
                assert_se(barrier_sync(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_place(&b));
                assert_se(barrier_sync(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test wait_next()
 * This places a barrier in the parent and syncs on it. The child sleeps while
 * the parent places the barrier and then waits for a barrier. The wait will
 * succeed as the child hasn't read the parent's barrier, yet. The following
 * barrier and sync synchronize the exit.
 */
TEST_BARRIER(test_barrier_wait_next,
        ({
                sleep_for(BASE_TIME);
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_wait_next(&b));
                assert_se(barrier_place(&b));
                assert_se(barrier_sync(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                set_alarm(BASE_TIME * 4);
                assert_se(barrier_place(&b));
                assert_se(barrier_sync(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test wait_next() multiple times
 * This places two barriers in the parent and waits for the child to exit. The
 * child sleeps 20ms so both barriers _should_ be in place. It then waits for
 * the parent to place the next barrier twice. The first call will fetch both
 * barriers and return. However, the second call will stall as the parent does
 * not place a 3rd barrier (the sleep caught two barriers). wait_next() is does
 * not look at barrier-links so this stall is expected. Thus this test times
 * out.
 */
TEST_BARRIER(test_barrier_wait_next_twice,
        ({
                sleep_for(BASE_TIME);
                set_alarm(BASE_TIME);
                assert_se(barrier_wait_next(&b));
                assert_se(barrier_wait_next(&b));
                assert_se(0);
        }),
        TEST_BARRIER_WAIT_ALARM(pid1),
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_place(&b));
                assert_se(barrier_place(&b));
                sleep_for(BASE_TIME * 2);
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test wait_next() with local barriers
 * This is the same as test_barrier_wait_next_twice, but places local barriers
 * between both waits. This does not have any effect on the wait so it times out
 * like the other test.
 */
TEST_BARRIER(test_barrier_wait_next_twice_local,
        ({
                sleep_for(BASE_TIME);
                set_alarm(BASE_TIME);
                assert_se(barrier_wait_next(&b));
                assert_se(barrier_place(&b));
                assert_se(barrier_place(&b));
                assert_se(barrier_wait_next(&b));
                assert_se(0);
        }),
        TEST_BARRIER_WAIT_ALARM(pid1),
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_place(&b));
                assert_se(barrier_place(&b));
                sleep_for(BASE_TIME * 2);
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test wait_next() with sync_next()
 * This is again the same as test_barrier_wait_next_twice but uses a
 * synced wait as the second wait. This works just fine because the local state
 * has no barriers placed, therefore, the remote is always in sync.
 */
TEST_BARRIER(test_barrier_wait_next_twice_sync,
        ({
                sleep_for(BASE_TIME);
                set_alarm(BASE_TIME);
                assert_se(barrier_wait_next(&b));
                assert_se(barrier_sync_next(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_place(&b));
                assert_se(barrier_place(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test wait_next() with sync_next() and local barriers
 * This is again the same as test_barrier_wait_next_twice_local but uses a
 * synced wait as the second wait. This works just fine because the local state
 * is in sync with the remote.
 */
TEST_BARRIER(test_barrier_wait_next_twice_local_sync,
        ({
                sleep_for(BASE_TIME);
                set_alarm(BASE_TIME);
                assert_se(barrier_wait_next(&b));
                assert_se(barrier_place(&b));
                assert_se(barrier_place(&b));
                assert_se(barrier_sync_next(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_place(&b));
                assert_se(barrier_place(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test sync_next() and sync()
 * This tests sync_*() synchronizations and makes sure they work fine if the
 * local state is behind the remote state.
 */
TEST_BARRIER(test_barrier_sync_next,
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_sync_next(&b));
                assert_se(barrier_sync(&b));
                assert_se(barrier_place(&b));
                assert_se(barrier_place(&b));
                assert_se(barrier_sync_next(&b));
                assert_se(barrier_sync_next(&b));
                assert_se(barrier_sync(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                set_alarm(BASE_TIME * 10);
                sleep_for(BASE_TIME);
                assert_se(barrier_place(&b));
                assert_se(barrier_place(&b));
                assert_se(barrier_sync(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test sync_next() and sync() with local barriers
 * This tests timeouts if sync_*() is used if local barriers are placed but the
 * remote didn't place any.
 */
TEST_BARRIER(test_barrier_sync_next_local,
        ({
                set_alarm(BASE_TIME);
                assert_se(barrier_place(&b));
                assert_se(barrier_sync_next(&b));
                assert_se(0);
        }),
        TEST_BARRIER_WAIT_ALARM(pid1),
        ({
                sleep_for(BASE_TIME * 2);
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test sync_next() and sync() with local barriers and abortion
 * This is the same as test_barrier_sync_next_local but aborts the sync in the
 * parent. Therefore, the sync_next() succeeds just fine due to the abortion.
 */
TEST_BARRIER(test_barrier_sync_next_local_abort,
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_place(&b));
                assert_se(!barrier_sync_next(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                assert_se(barrier_abort(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test matched wait_abortion()
 * This runs wait_abortion() with remote abortion.
 */
TEST_BARRIER(test_barrier_wait_abortion,
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_wait_abortion(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                assert_se(barrier_abort(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test unmatched wait_abortion()
 * This runs wait_abortion() without any remote abortion going on. It thus must
 * timeout.
 */
TEST_BARRIER(test_barrier_wait_abortion_unmatched,
        ({
                set_alarm(BASE_TIME);
                assert_se(barrier_wait_abortion(&b));
                assert_se(0);
        }),
        TEST_BARRIER_WAIT_ALARM(pid1),
        ({
                sleep_for(BASE_TIME * 2);
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test matched wait_abortion() with local abortion
 * This runs wait_abortion() with local and remote abortion.
 */
TEST_BARRIER(test_barrier_wait_abortion_local,
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_abort(&b));
                assert_se(!barrier_wait_abortion(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                assert_se(barrier_abort(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test unmatched wait_abortion() with local abortion
 * This runs wait_abortion() with only local abortion. This must time out.
 */
TEST_BARRIER(test_barrier_wait_abortion_local_unmatched,
        ({
                set_alarm(BASE_TIME);
                assert_se(barrier_abort(&b));
                assert_se(!barrier_wait_abortion(&b));
                assert_se(0);
        }),
        TEST_BARRIER_WAIT_ALARM(pid1),
        ({
                sleep_for(BASE_TIME * 2);
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test child exit
 * Place barrier and sync with the child. The child only exits()s, which should
 * cause an implicit abortion and wake the parent.
 */
TEST_BARRIER(test_barrier_exit,
        ({
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                set_alarm(BASE_TIME * 10);
                assert_se(barrier_place(&b));
                assert_se(!barrier_sync(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

/*
 * Test child exit with sleep
 * Same as test_barrier_exit but verifies the test really works due to the
 * child-exit. We add a usleep() which triggers the alarm in the parent and
 * causes the test to time out.
 */
TEST_BARRIER(test_barrier_no_exit,
        ({
                sleep_for(BASE_TIME * 2);
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                set_alarm(BASE_TIME);
                assert_se(barrier_place(&b));
                assert_se(!barrier_sync(&b));
        }),
        TEST_BARRIER_WAIT_ALARM(pid2));

/*
 * Test pending exit against sync
 * The parent places a barrier *and* exits. The 20ms wait in the child
 * guarantees both are pending. However, our logic prefers pending barriers over
 * pending exit-abortions (unlike normal abortions), thus the wait_next() must
 * succeed, same for the sync_next() as our local barrier-count is smaller than
 * the remote. Once we place a barrier our count is equal, so the sync still
 * succeeds. Only if we place one more barrier, we're ahead of the remote, thus
 * we will fail due to HUP on the pipe.
 */
TEST_BARRIER(test_barrier_pending_exit,
        ({
                set_alarm(BASE_TIME * 4);
                sleep_for(BASE_TIME * 2);
                assert_se(barrier_wait_next(&b));
                assert_se(barrier_sync_next(&b));
                assert_se(barrier_place(&b));
                assert_se(barrier_sync_next(&b));
                assert_se(barrier_place(&b));
                assert_se(!barrier_sync_next(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid1),
        ({
                assert_se(barrier_place(&b));
        }),
        TEST_BARRIER_WAIT_SUCCESS(pid2));

int main(int argc, char *argv[]) {
        log_parse_environment();
        log_open();

        test_barrier_sync();
        test_barrier_wait_next();
        test_barrier_wait_next_twice();
        test_barrier_wait_next_twice_sync();
        test_barrier_wait_next_twice_local();
        test_barrier_wait_next_twice_local_sync();
        test_barrier_sync_next();
        test_barrier_sync_next_local();
        test_barrier_sync_next_local_abort();
        test_barrier_wait_abortion();
        test_barrier_wait_abortion_unmatched();
        test_barrier_wait_abortion_local();
        test_barrier_wait_abortion_local_unmatched();
        test_barrier_exit();
        test_barrier_no_exit();
        test_barrier_pending_exit();

        return 0;
}