1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /******************************************************************************
3 *
4 * Copyright © International Business Machines Corp., 2006-2008
5 *
6 * DESCRIPTION
7 * This test excercises the futex syscall op codes needed for requeuing
8 * priority inheritance aware POSIX condition variables and mutexes.
9 *
10 * AUTHORS
11 * Sripathi Kodi <sripathik@in.ibm.com>
12 * Darren Hart <dvhart@linux.intel.com>
13 *
14 * HISTORY
15 * 2008-Jan-13: Initial version by Sripathi Kodi <sripathik@in.ibm.com>
16 * 2009-Nov-6: futex test adaptation by Darren Hart <dvhart@linux.intel.com>
17 *
18 *****************************************************************************/
19
20 #define _GNU_SOURCE
21
22 #include <errno.h>
23 #include <limits.h>
24 #include <pthread.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <signal.h>
28 #include <string.h>
29 #include "atomic.h"
30 #include "futextest.h"
31 #include "logging.h"
32
33 #define TEST_NAME "futex-requeue-pi"
34 #define MAX_WAKE_ITERS 1000
35 #define THREAD_MAX 10
36 #define SIGNAL_PERIOD_US 100
37
38 atomic_t waiters_blocked = ATOMIC_INITIALIZER;
39 atomic_t waiters_woken = ATOMIC_INITIALIZER;
40
41 futex_t f1 = FUTEX_INITIALIZER;
42 futex_t f2 = FUTEX_INITIALIZER;
43 futex_t wake_complete = FUTEX_INITIALIZER;
44
45 /* Test option defaults */
46 static long timeout_ns;
47 static int broadcast;
48 static int owner;
49 static int locked;
50
51 struct thread_arg {
52 long id;
53 struct timespec *timeout;
54 int lock;
55 int ret;
56 };
57 #define THREAD_ARG_INITIALIZER { 0, NULL, 0, 0 }
58
59 void usage(char *prog)
60 {
61 printf("Usage: %s\n", prog);
62 printf(" -b Broadcast wakeup (all waiters)\n");
63 printf(" -c Use color\n");
64 printf(" -h Display this help message\n");
65 printf(" -l Lock the pi futex across requeue\n");
66 printf(" -o Use a third party pi futex owner during requeue (cancels -l)\n");
67 printf(" -t N Timeout in nanoseconds (default: 0)\n");
68 printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
69 VQUIET, VCRITICAL, VINFO);
70 }
71
72 int create_rt_thread(pthread_t *pth, void*(*func)(void *), void *arg,
73 int policy, int prio)
74 {
75 int ret;
76 struct sched_param schedp;
77 pthread_attr_t attr;
78
79 pthread_attr_init(&attr);
80 memset(&schedp, 0, sizeof(schedp));
81
82 ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
83 if (ret) {
84 error("pthread_attr_setinheritsched\n", ret);
85 return -1;
86 }
87
88 ret = pthread_attr_setschedpolicy(&attr, policy);
89 if (ret) {
90 error("pthread_attr_setschedpolicy\n", ret);
91 return -1;
92 }
93
94 schedp.sched_priority = prio;
95 ret = pthread_attr_setschedparam(&attr, &schedp);
96 if (ret) {
97 error("pthread_attr_setschedparam\n", ret);
98 return -1;
99 }
100
101 ret = pthread_create(pth, &attr, func, arg);
102 if (ret) {
103 error("pthread_create\n", ret);
104 return -1;
105 }
106 return 0;
107 }
108
109
110 void *waiterfn(void *arg)
111 {
112 struct thread_arg *args = (struct thread_arg *)arg;
113 futex_t old_val;
114
115 info("Waiter %ld: running\n", args->id);
116 /* Each thread sleeps for a different amount of time
117 * This is to avoid races, because we don't lock the
118 * external mutex here */
119 usleep(1000 * (long)args->id);
120
121 old_val = f1;
122 atomic_inc(&waiters_blocked);
123 info("Calling futex_wait_requeue_pi: %p (%u) -> %p\n",
124 &f1, f1, &f2);
125 args->ret = futex_wait_requeue_pi(&f1, old_val, &f2, args->timeout,
126 FUTEX_PRIVATE_FLAG);
127
128 info("waiter %ld woke with %d %s\n", args->id, args->ret,
129 args->ret < 0 ? strerror(errno) : "");
130 atomic_inc(&waiters_woken);
131 if (args->ret < 0) {
132 if (args->timeout && errno == ETIMEDOUT)
133 args->ret = 0;
134 else {
135 args->ret = RET_ERROR;
136 error("futex_wait_requeue_pi\n", errno);
137 }
138 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
139 }
140 futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
141
142 info("Waiter %ld: exiting with %d\n", args->id, args->ret);
143 pthread_exit((void *)&args->ret);
144 }
145
146 void *broadcast_wakerfn(void *arg)
147 {
148 struct thread_arg *args = (struct thread_arg *)arg;
149 int nr_requeue = INT_MAX;
150 int task_count = 0;
151 futex_t old_val;
152 int nr_wake = 1;
153 int i = 0;
154
155 info("Waker: waiting for waiters to block\n");
156 while (waiters_blocked.val < THREAD_MAX)
157 usleep(1000);
158 usleep(1000);
159
160 info("Waker: Calling broadcast\n");
161 if (args->lock) {
162 info("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n", f2, &f2);
163 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
164 }
165 continue_requeue:
166 old_val = f1;
167 args->ret = futex_cmp_requeue_pi(&f1, old_val, &f2, nr_wake, nr_requeue,
168 FUTEX_PRIVATE_FLAG);
169 if (args->ret < 0) {
170 args->ret = RET_ERROR;
171 error("FUTEX_CMP_REQUEUE_PI failed\n", errno);
172 } else if (++i < MAX_WAKE_ITERS) {
173 task_count += args->ret;
174 if (task_count < THREAD_MAX - waiters_woken.val)
175 goto continue_requeue;
176 } else {
177 error("max broadcast iterations (%d) reached with %d/%d tasks woken or requeued\n",
178 0, MAX_WAKE_ITERS, task_count, THREAD_MAX);
179 args->ret = RET_ERROR;
180 }
181
182 futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);
183
184 if (args->lock)
185 futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
186
187 if (args->ret > 0)
188 args->ret = task_count;
189
190 info("Waker: exiting with %d\n", args->ret);
191 pthread_exit((void *)&args->ret);
192 }
193
194 void *signal_wakerfn(void *arg)
195 {
196 struct thread_arg *args = (struct thread_arg *)arg;
197 unsigned int old_val;
198 int nr_requeue = 0;
199 int task_count = 0;
200 int nr_wake = 1;
201 int i = 0;
202
203 info("Waker: waiting for waiters to block\n");
204 while (waiters_blocked.val < THREAD_MAX)
205 usleep(1000);
206 usleep(1000);
207
208 while (task_count < THREAD_MAX && waiters_woken.val < THREAD_MAX) {
209 info("task_count: %d, waiters_woken: %d\n",
210 task_count, waiters_woken.val);
211 if (args->lock) {
212 info("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n",
213 f2, &f2);
214 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
215 }
216 info("Waker: Calling signal\n");
217 /* cond_signal */
218 old_val = f1;
219 args->ret = futex_cmp_requeue_pi(&f1, old_val, &f2,
220 nr_wake, nr_requeue,
221 FUTEX_PRIVATE_FLAG);
222 if (args->ret < 0)
223 args->ret = -errno;
224 info("futex: %x\n", f2);
225 if (args->lock) {
226 info("Calling FUTEX_UNLOCK_PI on mutex=%x @ %p\n",
227 f2, &f2);
228 futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
229 }
230 info("futex: %x\n", f2);
231 if (args->ret < 0) {
232 error("FUTEX_CMP_REQUEUE_PI failed\n", errno);
233 args->ret = RET_ERROR;
234 break;
235 }
236
237 task_count += args->ret;
238 usleep(SIGNAL_PERIOD_US);
239 i++;
240 /* we have to loop at least THREAD_MAX times */
241 if (i > MAX_WAKE_ITERS + THREAD_MAX) {
242 error("max signaling iterations (%d) reached, giving up on pending waiters.\n",
243 0, MAX_WAKE_ITERS + THREAD_MAX);
244 args->ret = RET_ERROR;
245 break;
246 }
247 }
248
249 futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);
250
251 if (args->ret >= 0)
252 args->ret = task_count;
253
254 info("Waker: exiting with %d\n", args->ret);
255 info("Waker: waiters_woken: %d\n", waiters_woken.val);
256 pthread_exit((void *)&args->ret);
257 }
258
259 void *third_party_blocker(void *arg)
260 {
261 struct thread_arg *args = (struct thread_arg *)arg;
262 int ret2 = 0;
263
264 args->ret = futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
265 if (args->ret)
266 goto out;
267 args->ret = futex_wait(&wake_complete, wake_complete, NULL,
268 FUTEX_PRIVATE_FLAG);
269 ret2 = futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
270
271 out:
272 if (args->ret || ret2) {
273 error("third_party_blocker() futex error", 0);
274 args->ret = RET_ERROR;
275 }
276
277 pthread_exit((void *)&args->ret);
278 }
279
280 int unit_test(int broadcast, long lock, int third_party_owner, long timeout_ns)
281 {
282 void *(*wakerfn)(void *) = signal_wakerfn;
283 struct thread_arg blocker_arg = THREAD_ARG_INITIALIZER;
284 struct thread_arg waker_arg = THREAD_ARG_INITIALIZER;
285 pthread_t waiter[THREAD_MAX], waker, blocker;
286 struct timespec ts, *tsp = NULL;
287 struct thread_arg args[THREAD_MAX];
288 int *waiter_ret;
289 int i, ret = RET_PASS;
290
291 if (timeout_ns) {
292 time_t secs;
293
294 info("timeout_ns = %ld\n", timeout_ns);
295 ret = clock_gettime(CLOCK_MONOTONIC, &ts);
296 secs = (ts.tv_nsec + timeout_ns) / 1000000000;
297 ts.tv_nsec = ((int64_t)ts.tv_nsec + timeout_ns) % 1000000000;
298 ts.tv_sec += secs;
299 info("ts.tv_sec = %ld\n", ts.tv_sec);
300 info("ts.tv_nsec = %ld\n", ts.tv_nsec);
301 tsp = &ts;
302 }
303
304 if (broadcast)
305 wakerfn = broadcast_wakerfn;
306
307 if (third_party_owner) {
308 if (create_rt_thread(&blocker, third_party_blocker,
309 (void *)&blocker_arg, SCHED_FIFO, 1)) {
310 error("Creating third party blocker thread failed\n",
311 errno);
312 ret = RET_ERROR;
313 goto out;
314 }
315 }
316
317 atomic_set(&waiters_woken, 0);
318 for (i = 0; i < THREAD_MAX; i++) {
319 args[i].id = i;
320 args[i].timeout = tsp;
321 info("Starting thread %d\n", i);
322 if (create_rt_thread(&waiter[i], waiterfn, (void *)&args[i],
323 SCHED_FIFO, 1)) {
324 error("Creating waiting thread failed\n", errno);
325 ret = RET_ERROR;
326 goto out;
327 }
328 }
329 waker_arg.lock = lock;
330 if (create_rt_thread(&waker, wakerfn, (void *)&waker_arg,
331 SCHED_FIFO, 1)) {
332 error("Creating waker thread failed\n", errno);
333 ret = RET_ERROR;
334 goto out;
335 }
336
337 /* Wait for threads to finish */
338 /* Store the first error or failure encountered in waiter_ret */
339 waiter_ret = &args[0].ret;
340 for (i = 0; i < THREAD_MAX; i++)
341 pthread_join(waiter[i],
342 *waiter_ret ? NULL : (void **)&waiter_ret);
343
344 if (third_party_owner)
345 pthread_join(blocker, NULL);
346 pthread_join(waker, NULL);
347
348 out:
349 if (!ret) {
350 if (*waiter_ret)
351 ret = *waiter_ret;
352 else if (waker_arg.ret < 0)
353 ret = waker_arg.ret;
354 else if (blocker_arg.ret)
355 ret = blocker_arg.ret;
356 }
357
358 return ret;
359 }
360
361 int main(int argc, char *argv[])
362 {
363 char *test_name;
364 int c, ret;
365
366 while ((c = getopt(argc, argv, "bchlot:v:")) != -1) {
367 switch (c) {
368 case 'b':
369 broadcast = 1;
370 break;
371 case 'c':
372 log_color(1);
373 break;
374 case 'h':
375 usage(basename(argv[0]));
376 exit(0);
377 case 'l':
378 locked = 1;
379 break;
380 case 'o':
381 owner = 1;
382 locked = 0;
383 break;
384 case 't':
385 timeout_ns = atoi(optarg);
386 break;
387 case 'v':
388 log_verbosity(atoi(optarg));
389 break;
390 default:
391 usage(basename(argv[0]));
392 exit(1);
393 }
394 }
395
396 ksft_print_header();
397 ksft_set_plan(1);
398 ksft_print_msg("%s: Test requeue functionality\n", basename(argv[0]));
399 ksft_print_msg(
400 "\tArguments: broadcast=%d locked=%d owner=%d timeout=%ldns\n",
401 broadcast, locked, owner, timeout_ns);
402
403 ret = asprintf(&test_name,
404 "%s broadcast=%d locked=%d owner=%d timeout=%ldns",
405 TEST_NAME, broadcast, locked, owner, timeout_ns);
406 if (ret < 0) {
407 ksft_print_msg("Failed to generate test name\n");
408 test_name = TEST_NAME;
409 }
410
411 /*
412 * FIXME: unit_test is obsolete now that we parse options and the
413 * various style of runs are done by run.sh - simplify the code and move
414 * unit_test into main()
415 */
416 ret = unit_test(broadcast, locked, owner, timeout_ns);
417
418 print_result(test_name, ret);
419 return ret;
420 }
421
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