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 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/* Test option defaults */
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	/* Each thread sleeps for a different amount of time
118	 * This is to avoid races, because we don't lock the
119	 * external mutex here */
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		/* cond_signal */
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		/* we have to loop at least THREAD_MAX times */
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	/* Wait for threads to finish */
339	/* Store the first error or failure encountered in waiter_ret */
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	 * FIXME: unit_test is obsolete now that we parse options and the
402	 * various style of runs are done by run.sh - simplify the code and move
403	 * unit_test into main()
404	 */
405	ret = unit_test(broadcast, locked, owner, timeout_ns);
406
407	print_result(ret);
408	return ret;
409}
410