54cd5c414e82c487f3c57094b84f5ab5cf960604
[sfrench/cifs-2.6.git] / tools / testing / selftests / futex / functional / futex_requeue_pi.c
1 /******************************************************************************
2  *
3  *   Copyright © International Business Machines  Corp., 2006-2008
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  * DESCRIPTION
11  *      This test excercises the futex syscall op codes needed for requeuing
12  *      priority inheritance aware POSIX condition variables and mutexes.
13  *
14  * AUTHORS
15  *      Sripathi Kodi <sripathik@in.ibm.com>
16  *      Darren Hart <dvhart@linux.intel.com>
17  *
18  * HISTORY
19  *      2008-Jan-13: Initial version by Sripathi Kodi <sripathik@in.ibm.com>
20  *      2009-Nov-6: futex test adaptation by Darren Hart <dvhart@linux.intel.com>
21  *
22  *****************************************************************************/
23
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 TEST_NAME "futex-requeue-pi"
36 #define MAX_WAKE_ITERS 1000
37 #define THREAD_MAX 10
38 #define SIGNAL_PERIOD_US 100
39
40 atomic_t waiters_blocked = ATOMIC_INITIALIZER;
41 atomic_t waiters_woken = ATOMIC_INITIALIZER;
42
43 futex_t f1 = FUTEX_INITIALIZER;
44 futex_t f2 = FUTEX_INITIALIZER;
45 futex_t wake_complete = FUTEX_INITIALIZER;
46
47 /* Test option defaults */
48 static long timeout_ns;
49 static int broadcast;
50 static int owner;
51 static int locked;
52
53 struct thread_arg {
54         long id;
55         struct timespec *timeout;
56         int lock;
57         int ret;
58 };
59 #define THREAD_ARG_INITIALIZER { 0, NULL, 0, 0 }
60
61 void usage(char *prog)
62 {
63         printf("Usage: %s\n", prog);
64         printf("  -b    Broadcast wakeup (all waiters)\n");
65         printf("  -c    Use color\n");
66         printf("  -h    Display this help message\n");
67         printf("  -l    Lock the pi futex across requeue\n");
68         printf("  -o    Use a third party pi futex owner during requeue (cancels -l)\n");
69         printf("  -t N  Timeout in nanoseconds (default: 0)\n");
70         printf("  -v L  Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
71                VQUIET, VCRITICAL, VINFO);
72 }
73
74 int create_rt_thread(pthread_t *pth, void*(*func)(void *), void *arg,
75                      int policy, int prio)
76 {
77         int ret;
78         struct sched_param schedp;
79         pthread_attr_t attr;
80
81         pthread_attr_init(&attr);
82         memset(&schedp, 0, sizeof(schedp));
83
84         ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
85         if (ret) {
86                 error("pthread_attr_setinheritsched\n", ret);
87                 return -1;
88         }
89
90         ret = pthread_attr_setschedpolicy(&attr, policy);
91         if (ret) {
92                 error("pthread_attr_setschedpolicy\n", ret);
93                 return -1;
94         }
95
96         schedp.sched_priority = prio;
97         ret = pthread_attr_setschedparam(&attr, &schedp);
98         if (ret) {
99                 error("pthread_attr_setschedparam\n", ret);
100                 return -1;
101         }
102
103         ret = pthread_create(pth, &attr, func, arg);
104         if (ret) {
105                 error("pthread_create\n", ret);
106                 return -1;
107         }
108         return 0;
109 }
110
111
112 void *waiterfn(void *arg)
113 {
114         struct thread_arg *args = (struct thread_arg *)arg;
115         futex_t old_val;
116
117         info("Waiter %ld: running\n", args->id);
118         /* Each thread sleeps for a different amount of time
119          * This is to avoid races, because we don't lock the
120          * external mutex here */
121         usleep(1000 * (long)args->id);
122
123         old_val = f1;
124         atomic_inc(&waiters_blocked);
125         info("Calling futex_wait_requeue_pi: %p (%u) -> %p\n",
126              &f1, f1, &f2);
127         args->ret = futex_wait_requeue_pi(&f1, old_val, &f2, args->timeout,
128                                           FUTEX_PRIVATE_FLAG);
129
130         info("waiter %ld woke with %d %s\n", args->id, args->ret,
131              args->ret < 0 ? strerror(errno) : "");
132         atomic_inc(&waiters_woken);
133         if (args->ret < 0) {
134                 if (args->timeout && errno == ETIMEDOUT)
135                         args->ret = 0;
136                 else {
137                         args->ret = RET_ERROR;
138                         error("futex_wait_requeue_pi\n", errno);
139                 }
140                 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
141         }
142         futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
143
144         info("Waiter %ld: exiting with %d\n", args->id, args->ret);
145         pthread_exit((void *)&args->ret);
146 }
147
148 void *broadcast_wakerfn(void *arg)
149 {
150         struct thread_arg *args = (struct thread_arg *)arg;
151         int nr_requeue = INT_MAX;
152         int task_count = 0;
153         futex_t old_val;
154         int nr_wake = 1;
155         int i = 0;
156
157         info("Waker: waiting for waiters to block\n");
158         while (waiters_blocked.val < THREAD_MAX)
159                 usleep(1000);
160         usleep(1000);
161
162         info("Waker: Calling broadcast\n");
163         if (args->lock) {
164                 info("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n", f2, &f2);
165                 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
166         }
167  continue_requeue:
168         old_val = f1;
169         args->ret = futex_cmp_requeue_pi(&f1, old_val, &f2, nr_wake, nr_requeue,
170                                    FUTEX_PRIVATE_FLAG);
171         if (args->ret < 0) {
172                 args->ret = RET_ERROR;
173                 error("FUTEX_CMP_REQUEUE_PI failed\n", errno);
174         } else if (++i < MAX_WAKE_ITERS) {
175                 task_count += args->ret;
176                 if (task_count < THREAD_MAX - waiters_woken.val)
177                         goto continue_requeue;
178         } else {
179                 error("max broadcast iterations (%d) reached with %d/%d tasks woken or requeued\n",
180                        0, MAX_WAKE_ITERS, task_count, THREAD_MAX);
181                 args->ret = RET_ERROR;
182         }
183
184         futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);
185
186         if (args->lock)
187                 futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
188
189         if (args->ret > 0)
190                 args->ret = task_count;
191
192         info("Waker: exiting with %d\n", args->ret);
193         pthread_exit((void *)&args->ret);
194 }
195
196 void *signal_wakerfn(void *arg)
197 {
198         struct thread_arg *args = (struct thread_arg *)arg;
199         unsigned int old_val;
200         int nr_requeue = 0;
201         int task_count = 0;
202         int nr_wake = 1;
203         int i = 0;
204
205         info("Waker: waiting for waiters to block\n");
206         while (waiters_blocked.val < THREAD_MAX)
207                 usleep(1000);
208         usleep(1000);
209
210         while (task_count < THREAD_MAX && waiters_woken.val < THREAD_MAX) {
211                 info("task_count: %d, waiters_woken: %d\n",
212                      task_count, waiters_woken.val);
213                 if (args->lock) {
214                         info("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n",
215                              f2, &f2);
216                         futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
217                 }
218                 info("Waker: Calling signal\n");
219                 /* cond_signal */
220                 old_val = f1;
221                 args->ret = futex_cmp_requeue_pi(&f1, old_val, &f2,
222                                                  nr_wake, nr_requeue,
223                                                  FUTEX_PRIVATE_FLAG);
224                 if (args->ret < 0)
225                         args->ret = -errno;
226                 info("futex: %x\n", f2);
227                 if (args->lock) {
228                         info("Calling FUTEX_UNLOCK_PI on mutex=%x @ %p\n",
229                              f2, &f2);
230                         futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
231                 }
232                 info("futex: %x\n", f2);
233                 if (args->ret < 0) {
234                         error("FUTEX_CMP_REQUEUE_PI failed\n", errno);
235                         args->ret = RET_ERROR;
236                         break;
237                 }
238
239                 task_count += args->ret;
240                 usleep(SIGNAL_PERIOD_US);
241                 i++;
242                 /* we have to loop at least THREAD_MAX times */
243                 if (i > MAX_WAKE_ITERS + THREAD_MAX) {
244                         error("max signaling iterations (%d) reached, giving up on pending waiters.\n",
245                               0, MAX_WAKE_ITERS + THREAD_MAX);
246                         args->ret = RET_ERROR;
247                         break;
248                 }
249         }
250
251         futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);
252
253         if (args->ret >= 0)
254                 args->ret = task_count;
255
256         info("Waker: exiting with %d\n", args->ret);
257         info("Waker: waiters_woken: %d\n", waiters_woken.val);
258         pthread_exit((void *)&args->ret);
259 }
260
261 void *third_party_blocker(void *arg)
262 {
263         struct thread_arg *args = (struct thread_arg *)arg;
264         int ret2 = 0;
265
266         args->ret = futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
267         if (args->ret)
268                 goto out;
269         args->ret = futex_wait(&wake_complete, wake_complete, NULL,
270                                FUTEX_PRIVATE_FLAG);
271         ret2 = futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
272
273  out:
274         if (args->ret || ret2) {
275                 error("third_party_blocker() futex error", 0);
276                 args->ret = RET_ERROR;
277         }
278
279         pthread_exit((void *)&args->ret);
280 }
281
282 int unit_test(int broadcast, long lock, int third_party_owner, long timeout_ns)
283 {
284         void *(*wakerfn)(void *) = signal_wakerfn;
285         struct thread_arg blocker_arg = THREAD_ARG_INITIALIZER;
286         struct thread_arg waker_arg = THREAD_ARG_INITIALIZER;
287         pthread_t waiter[THREAD_MAX], waker, blocker;
288         struct timespec ts, *tsp = NULL;
289         struct thread_arg args[THREAD_MAX];
290         int *waiter_ret;
291         int i, ret = RET_PASS;
292
293         if (timeout_ns) {
294                 time_t secs;
295
296                 info("timeout_ns = %ld\n", timeout_ns);
297                 ret = clock_gettime(CLOCK_MONOTONIC, &ts);
298                 secs = (ts.tv_nsec + timeout_ns) / 1000000000;
299                 ts.tv_nsec = ((int64_t)ts.tv_nsec + timeout_ns) % 1000000000;
300                 ts.tv_sec += secs;
301                 info("ts.tv_sec  = %ld\n", ts.tv_sec);
302                 info("ts.tv_nsec = %ld\n", ts.tv_nsec);
303                 tsp = &ts;
304         }
305
306         if (broadcast)
307                 wakerfn = broadcast_wakerfn;
308
309         if (third_party_owner) {
310                 if (create_rt_thread(&blocker, third_party_blocker,
311                                      (void *)&blocker_arg, SCHED_FIFO, 1)) {
312                         error("Creating third party blocker thread failed\n",
313                               errno);
314                         ret = RET_ERROR;
315                         goto out;
316                 }
317         }
318
319         atomic_set(&waiters_woken, 0);
320         for (i = 0; i < THREAD_MAX; i++) {
321                 args[i].id = i;
322                 args[i].timeout = tsp;
323                 info("Starting thread %d\n", i);
324                 if (create_rt_thread(&waiter[i], waiterfn, (void *)&args[i],
325                                      SCHED_FIFO, 1)) {
326                         error("Creating waiting thread failed\n", errno);
327                         ret = RET_ERROR;
328                         goto out;
329                 }
330         }
331         waker_arg.lock = lock;
332         if (create_rt_thread(&waker, wakerfn, (void *)&waker_arg,
333                              SCHED_FIFO, 1)) {
334                 error("Creating waker thread failed\n", errno);
335                 ret = RET_ERROR;
336                 goto out;
337         }
338
339         /* Wait for threads to finish */
340         /* Store the first error or failure encountered in waiter_ret */
341         waiter_ret = &args[0].ret;
342         for (i = 0; i < THREAD_MAX; i++)
343                 pthread_join(waiter[i],
344                              *waiter_ret ? NULL : (void **)&waiter_ret);
345
346         if (third_party_owner)
347                 pthread_join(blocker, NULL);
348         pthread_join(waker, NULL);
349
350 out:
351         if (!ret) {
352                 if (*waiter_ret)
353                         ret = *waiter_ret;
354                 else if (waker_arg.ret < 0)
355                         ret = waker_arg.ret;
356                 else if (blocker_arg.ret)
357                         ret = blocker_arg.ret;
358         }
359
360         return ret;
361 }
362
363 int main(int argc, char *argv[])
364 {
365         int c, ret;
366
367         while ((c = getopt(argc, argv, "bchlot:v:")) != -1) {
368                 switch (c) {
369                 case 'b':
370                         broadcast = 1;
371                         break;
372                 case 'c':
373                         log_color(1);
374                         break;
375                 case 'h':
376                         usage(basename(argv[0]));
377                         exit(0);
378                 case 'l':
379                         locked = 1;
380                         break;
381                 case 'o':
382                         owner = 1;
383                         locked = 0;
384                         break;
385                 case 't':
386                         timeout_ns = atoi(optarg);
387                         break;
388                 case 'v':
389                         log_verbosity(atoi(optarg));
390                         break;
391                 default:
392                         usage(basename(argv[0]));
393                         exit(1);
394                 }
395         }
396
397         ksft_print_header();
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         /*
404          * FIXME: unit_test is obsolete now that we parse options and the
405          * various style of runs are done by run.sh - simplify the code and move
406          * unit_test into main()
407          */
408         ret = unit_test(broadcast, locked, owner, timeout_ns);
409
410         print_result(TEST_NAME, ret);
411         return ret;
412 }