1/***
2  This file is part of PulseAudio.
3
4  Copyright 2014 David Henningsson, Canonical Ltd.
5
6  PulseAudio is free software; you can redistribute it and/or modify
7  it under the terms of the GNU Lesser General Public License as published
8  by the Free Software Foundation; either version 2.1 of the License,
9  or (at your option) any later version.
10
11  PulseAudio is distributed in the hope that it will be useful, but
12  WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  General Public License for more details.
15
16  You should have received a copy of the GNU Lesser General Public License
17  along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
18***/
19
20/* This test spawns two threads on distinct cpu-cores that pass a value
21 * between each other through shared memory protected by pa_atomic_t.
22 * Thread "left" continuously increments a value and writes its contents to memory.
23 * Thread "right" continuously reads the value and checks whether it was incremented.
24 *
25 * With the pa_atomic_load/pa_atomic_store implementations based on __sync_synchronize,
26 * this will fail after some time (sometimes 2 seconds, sometimes 8 hours) at least
27 * on ARM Cortex-A53 and ARM Cortex-A57 systems.
28 *
29 * On x86_64, it does not.
30 *
31 * The chosen implementation in some way mimics a situation that can also occur
32 * using memfd srbchannel transport.
33 *
34 * NOTE: This is a long-running test, so don't execute in normal test suite.
35 *
36 * */
37
38#ifdef HAVE_CONFIG_H
39#include <config.h>
40#endif
41
42#include <unistd.h>
43#include <check.h>
44
45#include <pulsecore/thread.h>
46#include <pulse/rtclock.h>
47#include <pulse/xmalloc.h>
48#include <pulsecore/semaphore.h>
49#include <pthread.h>
50#ifdef __FreeBSD__
51#include <pthread_np.h>
52#endif
53#include <pulsecore/atomic.h>
54
55#define MEMORY_SIZE (8 * 2 * 1024 * 1024)
56
57
58typedef struct io_t {
59   pa_atomic_t *flag;
60   char* memory;
61#ifdef __FreeBSD__
62   cpuset_t cpuset;
63#else
64   cpu_set_t cpuset;
65#endif
66} io_t;
67
68static void read_func(void* data) {
69   io_t *io = (io_t *) data;
70   size_t expect = 0;
71   size_t value = 0;
72   pthread_setaffinity_np(pthread_self(), sizeof(io->cpuset), &io->cpuset);
73   while(1) {
74      if(pa_atomic_load(io->flag) == 1) {
75         memcpy(&value, io->memory, sizeof(value));
76         pa_atomic_sub(io->flag, 1);
77         ck_assert_uint_eq(value, expect);
78         ++expect;
79      }
80   }
81}
82
83static void write_func(void* data) {
84   io_t *io = (io_t *) data;
85   size_t value = 0;
86   pthread_setaffinity_np(pthread_self(), sizeof(io->cpuset), &io->cpuset);
87   while(1) {
88      if(pa_atomic_load(io->flag) == 0) {
89         memcpy(io->memory, &value, sizeof(value));
90         pa_atomic_add(io->flag, 1);
91         ++value;
92      }
93   }
94}
95
96START_TEST (atomic_test) {
97    pa_thread *thread1, *thread2;
98    io_t io1, io2;
99
100    char* memory = pa_xmalloc0(MEMORY_SIZE);
101    pa_atomic_t flag = PA_ATOMIC_INIT(0);
102    memset(memory, 0, MEMORY_SIZE);
103
104    /* intentionally misalign memory since srbchannel also does not
105     * always read/write aligned. Might be a red hering. */
106    io1.memory = io2.memory = memory + 1025;
107    io1.flag = io2.flag = &flag;
108
109    CPU_ZERO(&io1.cpuset);
110    CPU_SET(1, &io1.cpuset);
111    thread1 = pa_thread_new("left", &write_func, &io1);
112
113    CPU_ZERO(&io2.cpuset);
114    CPU_SET(3, &io2.cpuset);
115    thread2 = pa_thread_new("right", &read_func, &io2);
116    pa_thread_free(thread1);
117    pa_thread_free(thread2);
118    pa_xfree(memory);
119}
120END_TEST
121
122int main(int argc, char *argv[]) {
123    int failed = 0;
124    Suite *s;
125    TCase *tc;
126    SRunner *sr;
127
128    if (!getenv("MAKE_CHECK"))
129        pa_log_set_level(PA_LOG_DEBUG);
130
131    s = suite_create("atomic");
132    tc = tcase_create("atomic");
133    tcase_add_test(tc, atomic_test);
134    suite_add_tcase(s, tc);
135
136    sr = srunner_create(s);
137    srunner_run_all(sr, CK_NORMAL);
138    failed = srunner_ntests_failed(sr);
139    srunner_free(sr);
140
141    return (failed == 0) ? EXIT_SUCCESS : EXIT_FAILURE;
142}
143