futex_requeue.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright Collabora Ltd., 2021
  4 *
  5 * futex cmp requeue test by André Almeida <andrealmeid@collabora.com>
  6 */
  7
  8#include <pthread.h>
  9#include <limits.h>
 10
 11#include "futextest.h"
 12#include "kselftest_harness.h"
 13
 14#define timeout_ns  30000000
 15#define WAKE_WAIT_US 10000
 16
 17volatile futex_t *f1;
 18
 19void *waiterfn(void *arg)
 20{
 21	struct timespec to;
 22
 23	to.tv_sec = 0;
 24	to.tv_nsec = timeout_ns;
 25
 26	if (futex_wait(f1, *f1, &to, 0))
 27		printf("waiter failed errno %d\n", errno);
 28
 29	return NULL;
 30}
 31
 32TEST(requeue_single)
 33{
 34	volatile futex_t _f1 = 0;
 35	volatile futex_t f2 = 0;
 36	pthread_t waiter[10];
 37	int res;
 38
 39	f1 = &_f1;
 40
 41	/*
 42	 * Requeue a waiter from f1 to f2, and wake f2.
 43	 */
 44	if (pthread_create(&waiter[0], NULL, waiterfn, NULL))
 45		ksft_exit_fail_msg("pthread_create failed\n");
 46
 47	usleep(WAKE_WAIT_US);
 48
 49	ksft_print_dbg_msg("Requeuing 1 futex from f1 to f2\n");
 50	res = futex_cmp_requeue(f1, 0, &f2, 0, 1, 0);
 51	if (res != 1)
 52		ksft_test_result_fail("futex_requeue simple returned: %d %s\n",
 53				      res ? errno : res,
 54				      res ? strerror(errno) : "");
 55
 56	ksft_print_dbg_msg("Waking 1 futex at f2\n");
 57	res = futex_wake(&f2, 1, 0);
 58	if (res != 1) {
 59		ksft_test_result_fail("futex_requeue simple returned: %d %s\n",
 60				      res ? errno : res,
 61				      res ? strerror(errno) : "");
 62	} else {
 63		ksft_test_result_pass("futex_requeue simple succeeds\n");
 64	}
 65}
 66
 67TEST(requeue_multiple)
 68{
 69	volatile futex_t _f1 = 0;
 70	volatile futex_t f2 = 0;
 71	pthread_t waiter[10];
 72	int res, i;
 73
 74	f1 = &_f1;
 75
 76	/*
 77	 * Create 10 waiters at f1. At futex_requeue, wake 3 and requeue 7.
 78	 * At futex_wake, wake INT_MAX (should be exactly 7).
 79	 */
 80	for (i = 0; i < 10; i++) {
 81		if (pthread_create(&waiter[i], NULL, waiterfn, NULL))
 82			ksft_exit_fail_msg("pthread_create failed\n");
 83	}
 84
 85	usleep(WAKE_WAIT_US);
 86
 87	ksft_print_dbg_msg("Waking 3 futexes at f1 and requeuing 7 futexes from f1 to f2\n");
 88	res = futex_cmp_requeue(f1, 0, &f2, 3, 7, 0);
 89	if (res != 10) {
 90		ksft_test_result_fail("futex_requeue many returned: %d %s\n",
 91				      res ? errno : res,
 92				      res ? strerror(errno) : "");
 93	}
 94
 95	ksft_print_dbg_msg("Waking INT_MAX futexes at f2\n");
 96	res = futex_wake(&f2, INT_MAX, 0);
 97	if (res != 7) {
 98		ksft_test_result_fail("futex_requeue many returned: %d %s\n",
 99				      res ? errno : res,
100				      res ? strerror(errno) : "");
101	} else {
102		ksft_test_result_pass("futex_requeue many succeeds\n");
103	}
104}
105
106TEST_HARNESS_MAIN