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24#include <errno.h>
25#include <limits.h>
26#include <pthread.h>
27#include <stdio.h>
28#include <stdlib.h>
29#include <signal.h>
30#include <string.h>
31#include "atomic.h"
32#include "futextest.h"
33#include "logging.h"
34
35#define MAX_WAKE_ITERS 1000
36#define THREAD_MAX 10
37#define SIGNAL_PERIOD_US 100
38
39atomic_t waiters_blocked = ATOMIC_INITIALIZER;
40atomic_t waiters_woken = ATOMIC_INITIALIZER;
41
42futex_t f1 = FUTEX_INITIALIZER;
43futex_t f2 = FUTEX_INITIALIZER;
44futex_t wake_complete = FUTEX_INITIALIZER;
45
46
47static long timeout_ns;
48static int broadcast;
49static int owner;
50static int locked;
51
52struct thread_arg {
53 long id;
54 struct timespec *timeout;
55 int lock;
56 int ret;
57};
58#define THREAD_ARG_INITIALIZER { 0, NULL, 0, 0 }
59
60void usage(char *prog)
61{
62 printf("Usage: %s\n", prog);
63 printf(" -b Broadcast wakeup (all waiters)\n");
64 printf(" -c Use color\n");
65 printf(" -h Display this help message\n");
66 printf(" -l Lock the pi futex across requeue\n");
67 printf(" -o Use a third party pi futex owner during requeue (cancels -l)\n");
68 printf(" -t N Timeout in nanoseconds (default: 0)\n");
69 printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
70 VQUIET, VCRITICAL, VINFO);
71}
72
73int create_rt_thread(pthread_t *pth, void*(*func)(void *), void *arg,
74 int policy, int prio)
75{
76 int ret;
77 struct sched_param schedp;
78 pthread_attr_t attr;
79
80 pthread_attr_init(&attr);
81 memset(&schedp, 0, sizeof(schedp));
82
83 ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
84 if (ret) {
85 error("pthread_attr_setinheritsched\n", ret);
86 return -1;
87 }
88
89 ret = pthread_attr_setschedpolicy(&attr, policy);
90 if (ret) {
91 error("pthread_attr_setschedpolicy\n", ret);
92 return -1;
93 }
94
95 schedp.sched_priority = prio;
96 ret = pthread_attr_setschedparam(&attr, &schedp);
97 if (ret) {
98 error("pthread_attr_setschedparam\n", ret);
99 return -1;
100 }
101
102 ret = pthread_create(pth, &attr, func, arg);
103 if (ret) {
104 error("pthread_create\n", ret);
105 return -1;
106 }
107 return 0;
108}
109
110
111void *waiterfn(void *arg)
112{
113 struct thread_arg *args = (struct thread_arg *)arg;
114 futex_t old_val;
115
116 info("Waiter %ld: running\n", args->id);
117
118
119
120 usleep(1000 * (long)args->id);
121
122 old_val = f1;
123 atomic_inc(&waiters_blocked);
124 info("Calling futex_wait_requeue_pi: %p (%u) -> %p\n",
125 &f1, f1, &f2);
126 args->ret = futex_wait_requeue_pi(&f1, old_val, &f2, args->timeout,
127 FUTEX_PRIVATE_FLAG);
128
129 info("waiter %ld woke with %d %s\n", args->id, args->ret,
130 args->ret < 0 ? strerror(errno) : "");
131 atomic_inc(&waiters_woken);
132 if (args->ret < 0) {
133 if (args->timeout && errno == ETIMEDOUT)
134 args->ret = 0;
135 else {
136 args->ret = RET_ERROR;
137 error("futex_wait_requeue_pi\n", errno);
138 }
139 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
140 }
141 futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
142
143 info("Waiter %ld: exiting with %d\n", args->id, args->ret);
144 pthread_exit((void *)&args->ret);
145}
146
147void *broadcast_wakerfn(void *arg)
148{
149 struct thread_arg *args = (struct thread_arg *)arg;
150 int nr_requeue = INT_MAX;
151 int task_count = 0;
152 futex_t old_val;
153 int nr_wake = 1;
154 int i = 0;
155
156 info("Waker: waiting for waiters to block\n");
157 while (waiters_blocked.val < THREAD_MAX)
158 usleep(1000);
159 usleep(1000);
160
161 info("Waker: Calling broadcast\n");
162 if (args->lock) {
163 info("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n", f2, &f2);
164 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
165 }
166 continue_requeue:
167 old_val = f1;
168 args->ret = futex_cmp_requeue_pi(&f1, old_val, &f2, nr_wake, nr_requeue,
169 FUTEX_PRIVATE_FLAG);
170 if (args->ret < 0) {
171 args->ret = RET_ERROR;
172 error("FUTEX_CMP_REQUEUE_PI failed\n", errno);
173 } else if (++i < MAX_WAKE_ITERS) {
174 task_count += args->ret;
175 if (task_count < THREAD_MAX - waiters_woken.val)
176 goto continue_requeue;
177 } else {
178 error("max broadcast iterations (%d) reached with %d/%d tasks woken or requeued\n",
179 0, MAX_WAKE_ITERS, task_count, THREAD_MAX);
180 args->ret = RET_ERROR;
181 }
182
183 futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);
184
185 if (args->lock)
186 futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
187
188 if (args->ret > 0)
189 args->ret = task_count;
190
191 info("Waker: exiting with %d\n", args->ret);
192 pthread_exit((void *)&args->ret);
193}
194
195void *signal_wakerfn(void *arg)
196{
197 struct thread_arg *args = (struct thread_arg *)arg;
198 unsigned int old_val;
199 int nr_requeue = 0;
200 int task_count = 0;
201 int nr_wake = 1;
202 int i = 0;
203
204 info("Waker: waiting for waiters to block\n");
205 while (waiters_blocked.val < THREAD_MAX)
206 usleep(1000);
207 usleep(1000);
208
209 while (task_count < THREAD_MAX && waiters_woken.val < THREAD_MAX) {
210 info("task_count: %d, waiters_woken: %d\n",
211 task_count, waiters_woken.val);
212 if (args->lock) {
213 info("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n",
214 f2, &f2);
215 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
216 }
217 info("Waker: Calling signal\n");
218
219 old_val = f1;
220 args->ret = futex_cmp_requeue_pi(&f1, old_val, &f2,
221 nr_wake, nr_requeue,
222 FUTEX_PRIVATE_FLAG);
223 if (args->ret < 0)
224 args->ret = -errno;
225 info("futex: %x\n", f2);
226 if (args->lock) {
227 info("Calling FUTEX_UNLOCK_PI on mutex=%x @ %p\n",
228 f2, &f2);
229 futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
230 }
231 info("futex: %x\n", f2);
232 if (args->ret < 0) {
233 error("FUTEX_CMP_REQUEUE_PI failed\n", errno);
234 args->ret = RET_ERROR;
235 break;
236 }
237
238 task_count += args->ret;
239 usleep(SIGNAL_PERIOD_US);
240 i++;
241
242 if (i > MAX_WAKE_ITERS + THREAD_MAX) {
243 error("max signaling iterations (%d) reached, giving up on pending waiters.\n",
244 0, MAX_WAKE_ITERS + THREAD_MAX);
245 args->ret = RET_ERROR;
246 break;
247 }
248 }
249
250 futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);
251
252 if (args->ret >= 0)
253 args->ret = task_count;
254
255 info("Waker: exiting with %d\n", args->ret);
256 info("Waker: waiters_woken: %d\n", waiters_woken.val);
257 pthread_exit((void *)&args->ret);
258}
259
260void *third_party_blocker(void *arg)
261{
262 struct thread_arg *args = (struct thread_arg *)arg;
263 int ret2 = 0;
264
265 args->ret = futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
266 if (args->ret)
267 goto out;
268 args->ret = futex_wait(&wake_complete, wake_complete, NULL,
269 FUTEX_PRIVATE_FLAG);
270 ret2 = futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
271
272 out:
273 if (args->ret || ret2) {
274 error("third_party_blocker() futex error", 0);
275 args->ret = RET_ERROR;
276 }
277
278 pthread_exit((void *)&args->ret);
279}
280
281int unit_test(int broadcast, long lock, int third_party_owner, long timeout_ns)
282{
283 void *(*wakerfn)(void *) = signal_wakerfn;
284 struct thread_arg blocker_arg = THREAD_ARG_INITIALIZER;
285 struct thread_arg waker_arg = THREAD_ARG_INITIALIZER;
286 pthread_t waiter[THREAD_MAX], waker, blocker;
287 struct timespec ts, *tsp = NULL;
288 struct thread_arg args[THREAD_MAX];
289 int *waiter_ret;
290 int i, ret = RET_PASS;
291
292 if (timeout_ns) {
293 time_t secs;
294
295 info("timeout_ns = %ld\n", timeout_ns);
296 ret = clock_gettime(CLOCK_MONOTONIC, &ts);
297 secs = (ts.tv_nsec + timeout_ns) / 1000000000;
298 ts.tv_nsec = ((int64_t)ts.tv_nsec + timeout_ns) % 1000000000;
299 ts.tv_sec += secs;
300 info("ts.tv_sec = %ld\n", ts.tv_sec);
301 info("ts.tv_nsec = %ld\n", ts.tv_nsec);
302 tsp = &ts;
303 }
304
305 if (broadcast)
306 wakerfn = broadcast_wakerfn;
307
308 if (third_party_owner) {
309 if (create_rt_thread(&blocker, third_party_blocker,
310 (void *)&blocker_arg, SCHED_FIFO, 1)) {
311 error("Creating third party blocker thread failed\n",
312 errno);
313 ret = RET_ERROR;
314 goto out;
315 }
316 }
317
318 atomic_set(&waiters_woken, 0);
319 for (i = 0; i < THREAD_MAX; i++) {
320 args[i].id = i;
321 args[i].timeout = tsp;
322 info("Starting thread %d\n", i);
323 if (create_rt_thread(&waiter[i], waiterfn, (void *)&args[i],
324 SCHED_FIFO, 1)) {
325 error("Creating waiting thread failed\n", errno);
326 ret = RET_ERROR;
327 goto out;
328 }
329 }
330 waker_arg.lock = lock;
331 if (create_rt_thread(&waker, wakerfn, (void *)&waker_arg,
332 SCHED_FIFO, 1)) {
333 error("Creating waker thread failed\n", errno);
334 ret = RET_ERROR;
335 goto out;
336 }
337
338
339
340 waiter_ret = &args[0].ret;
341 for (i = 0; i < THREAD_MAX; i++)
342 pthread_join(waiter[i],
343 *waiter_ret ? NULL : (void **)&waiter_ret);
344
345 if (third_party_owner)
346 pthread_join(blocker, NULL);
347 pthread_join(waker, NULL);
348
349out:
350 if (!ret) {
351 if (*waiter_ret)
352 ret = *waiter_ret;
353 else if (waker_arg.ret < 0)
354 ret = waker_arg.ret;
355 else if (blocker_arg.ret)
356 ret = blocker_arg.ret;
357 }
358
359 return ret;
360}
361
362int main(int argc, char *argv[])
363{
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 printf("%s: Test requeue functionality\n", basename(argv[0]));
397 printf("\tArguments: broadcast=%d locked=%d owner=%d timeout=%ldns\n",
398 broadcast, locked, owner, timeout_ns);
399
400
401
402
403
404
405 ret = unit_test(broadcast, locked, owner, timeout_ns);
406
407 print_result(ret);
408 return ret;
409}
410
