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
38atomic_t waiters_blocked = ATOMIC_INITIALIZER;
39atomic_t waiters_woken = ATOMIC_INITIALIZER;
40
41futex_t f1 = FUTEX_INITIALIZER;
42futex_t f2 = FUTEX_INITIALIZER;
43futex_t wake_complete = FUTEX_INITIALIZER;
44
45/* Test option defaults */
46static long timeout_ns;
47static int broadcast;
48static int owner;
49static int locked;
50
51struct 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
59void 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
72int 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
110void *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
146void *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
194void *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
259void *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
280int 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
348out:
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
361int main(int argc, char *argv[])
362{
363	const 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