xref: /linux/tools/testing/selftests/futex/functional/futex_requeue.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
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 
17 volatile futex_t *f1;
18 
19 void *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 
32 TEST(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 
67 TEST(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 
106 TEST_HARNESS_MAIN
107