1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
/* Copyright (C) 2024 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include <pthread.h>
#include <signal.h>
#include <tap/basic.h>
#include "contrib/atomic.h"
#include "knot/server/dthreads.h"
#define THREADS 16
#define CYCLES1 100000
#define CYCLES2 2000000
#define CYCLES3 100000
#define UPPER 0xffffffff00000000
#define LOWER 0x00000000ffffffff
#define UPPER_PTR ((void *) UPPER)
#define LOWER_PTR ((void *) LOWER)
static volatile knot_atomic_uint64_t counter_add = 0;
static volatile knot_atomic_uint64_t counter_sub = 0;
static volatile knot_atomic_uint64_t atomic_var;
static volatile knot_atomic_ptr_t atomic_var2;
static int errors = 0;
static int uppers;
static int lowers;
static int uppers_count = 0;
static int lowers_count = 0;
static pthread_mutex_t mx;
static int thread_add(struct dthread *thread)
{
for (int i = 0; i < CYCLES1; i++) {
ATOMIC_ADD(counter_add, 7);
ATOMIC_SUB(counter_sub, 7);
}
return 0;
}
static int thread_set(struct dthread *thread)
{
u_int64_t val = (dt_get_id(thread) % 2) ? UPPER : LOWER;
for (int i = 0; i < CYCLES2; i++) {
ATOMIC_SET(atomic_var, val);
volatile u_int64_t read = ATOMIC_GET(atomic_var);
if (read != UPPER && read != LOWER) {
// Non-atomic counter, won't be accurate!
// However, it's sufficient for fault detection.
errors++;
}
}
return 0;
}
static int thread_xchg(struct dthread *thread)
{
void *val = (dt_get_id(thread) % 2) ? UPPER_PTR : LOWER_PTR;
pthread_mutex_lock(&mx);
if (val == UPPER_PTR) {
uppers++;
} else {
lowers++;
};
pthread_mutex_unlock(&mx);
for (int i = 0; i < CYCLES3; i++) {
val = ATOMIC_XCHG(atomic_var2, val);
if (val != UPPER_PTR && val != LOWER_PTR) {
// Non-atomic counter, won't be accurate!
// However, it's sufficient for fault detection.
errors++;
return 0;
}
}
pthread_mutex_lock(&mx);
if (val == UPPER_PTR) {
uppers_count++;
} else if (val == LOWER_PTR) {
lowers_count++;
};
pthread_mutex_unlock(&mx);
return 0;
}
// Signal handler
static void interrupt_handle(int s)
{
}
int main(int argc, char *argv[])
{
plan_lazy();
// Register service and signal handler
struct sigaction sa;
sa.sa_handler = interrupt_handle;
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sigaction(SIGALRM, &sa, NULL); // Interrupt
// Test for atomicity of ATOMIC_ADD and ATOMIC_SUB.
dt_unit_t *unit = dt_create(THREADS, thread_add, NULL, NULL);
dt_start(unit);
dt_join(unit);
dt_delete(&unit);
is_int(THREADS * CYCLES1 * 7, counter_add, "atomicity of ATOMIC_ADD");
is_int(THREADS * CYCLES1 * 7, -counter_sub, "atomicity of ATOMIC_SUB");
// Test for atomicity of ATOMIC_SET and ATOMIC_GET.
unit = dt_create(THREADS, thread_set, NULL, NULL);
dt_start(unit);
dt_join(unit);
dt_delete(&unit);
is_int(0, errors, "atomicity of ATOMIC_SET / ATOMIC_GET");
// Test for atomicity of ATOMIC_XCHG.
errors = 0;
uppers = 0; // Initialize in code so as to calm down Coverity.
lowers = 0; // Idem.
atomic_var2 = UPPER_PTR;
uppers++;
pthread_mutex_init(&mx, NULL);
unit = dt_create(THREADS, thread_xchg, NULL, NULL);
dt_start(unit);
dt_join(unit);
dt_delete(&unit);
pthread_mutex_destroy(&mx);
if (atomic_var2 == UPPER_PTR) {
uppers_count++;
} else if (atomic_var2 == LOWER_PTR) {
lowers_count++;
} else {
errors++;
}
is_int(0, errors, "set/get atomicity of ATOMIC_XCHG");
is_int(uppers, uppers_count, "atomicity of ATOMIC_XCHG");
is_int(lowers, lowers_count, "atomicity of ATOMIC_XCHG");
return 0;
}
|
