xref: /dpdk/app/test/test_atomic.c (revision 0d0dcd64)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #include <stdio.h>
6 #include <stdint.h>
7 #include <unistd.h>
8 #include <sys/queue.h>
9 
10 #include <rte_memory.h>
11 #include <rte_per_lcore.h>
12 #include <rte_launch.h>
13 #include <rte_atomic.h>
14 #include <rte_eal.h>
15 #include <rte_lcore.h>
16 
17 #include "test.h"
18 
19 /*
20  * Atomic Variables
21  * ================
22  *
23  * - The main test function performs three subtests. The first test
24  *   checks that the usual inc/dec/add/sub functions are working
25  *   correctly:
26  *
27  *   - Initialize 16-bit, 32-bit and 64-bit atomic variables to specific
28  *     values.
29  *
30  *   - These variables are incremented and decremented on each core at
31  *     the same time in ``test_atomic_usual()``.
32  *
33  *   - The function checks that once all lcores finish their function,
34  *     the value of the atomic variables are still the same.
35  *
36  * - The second test verifies the behavior of "test and set" functions.
37  *
38  *   - Initialize 16-bit, 32-bit and 64-bit atomic variables to zero.
39  *
40  *   - Invoke ``test_atomic_tas()`` on each lcore: before doing anything
41  *     else. The cores are waiting a synchro using ``while
42  *     (rte_atomic32_read(&val) == 0)`` which is triggered by the main test
43  *     function. Then all cores do a
44  *     ``rte_atomicXX_test_and_set()`` at the same time. If it is successful,
45  *     it increments another atomic counter.
46  *
47  *   - The main function checks that the atomic counter was incremented
48  *     twice only (one for 16-bit, one for 32-bit and one for 64-bit values).
49  *
50  * - Test "add/sub and return"
51  *
52  *   - Initialize 16-bit, 32-bit and 64-bit atomic variables to zero.
53  *
54  *   - Invoke ``test_atomic_addsub_return()`` on each lcore. Before doing
55  *     anything else, the cores are waiting a synchro. Each lcore does
56  *     this operation several times::
57  *
58  *       tmp = rte_atomicXX_add_return(&a, 1);
59  *       atomic_add(&count, tmp);
60  *       tmp = rte_atomicXX_sub_return(&a, 1);
61  *       atomic_sub(&count, tmp+1);
62  *
63  *   - At the end of the test, the *count* value must be 0.
64  */
65 
66 #define NUM_ATOMIC_TYPES 3
67 
68 #define N 10000
69 
70 static rte_atomic16_t a16;
71 static rte_atomic32_t a32;
72 static rte_atomic64_t a64;
73 static rte_atomic64_t count;
74 static rte_atomic32_t synchro;
75 
76 static int
77 test_atomic_usual(__attribute__((unused)) void *arg)
78 {
79 	unsigned i;
80 
81 	while (rte_atomic32_read(&synchro) == 0)
82 		;
83 
84 	for (i = 0; i < N; i++)
85 		rte_atomic16_inc(&a16);
86 	for (i = 0; i < N; i++)
87 		rte_atomic16_dec(&a16);
88 	for (i = 0; i < (N / 5); i++)
89 		rte_atomic16_add(&a16, 5);
90 	for (i = 0; i < (N / 5); i++)
91 		rte_atomic16_sub(&a16, 5);
92 
93 	for (i = 0; i < N; i++)
94 		rte_atomic32_inc(&a32);
95 	for (i = 0; i < N; i++)
96 		rte_atomic32_dec(&a32);
97 	for (i = 0; i < (N / 5); i++)
98 		rte_atomic32_add(&a32, 5);
99 	for (i = 0; i < (N / 5); i++)
100 		rte_atomic32_sub(&a32, 5);
101 
102 	for (i = 0; i < N; i++)
103 		rte_atomic64_inc(&a64);
104 	for (i = 0; i < N; i++)
105 		rte_atomic64_dec(&a64);
106 	for (i = 0; i < (N / 5); i++)
107 		rte_atomic64_add(&a64, 5);
108 	for (i = 0; i < (N / 5); i++)
109 		rte_atomic64_sub(&a64, 5);
110 
111 	return 0;
112 }
113 
114 static int
115 test_atomic_tas(__attribute__((unused)) void *arg)
116 {
117 	while (rte_atomic32_read(&synchro) == 0)
118 		;
119 
120 	if (rte_atomic16_test_and_set(&a16))
121 		rte_atomic64_inc(&count);
122 	if (rte_atomic32_test_and_set(&a32))
123 		rte_atomic64_inc(&count);
124 	if (rte_atomic64_test_and_set(&a64))
125 		rte_atomic64_inc(&count);
126 
127 	return 0;
128 }
129 
130 static int
131 test_atomic_addsub_and_return(__attribute__((unused)) void *arg)
132 {
133 	uint32_t tmp16;
134 	uint32_t tmp32;
135 	uint64_t tmp64;
136 	unsigned i;
137 
138 	while (rte_atomic32_read(&synchro) == 0)
139 		;
140 
141 	for (i = 0; i < N; i++) {
142 		tmp16 = rte_atomic16_add_return(&a16, 1);
143 		rte_atomic64_add(&count, tmp16);
144 
145 		tmp16 = rte_atomic16_sub_return(&a16, 1);
146 		rte_atomic64_sub(&count, tmp16+1);
147 
148 		tmp32 = rte_atomic32_add_return(&a32, 1);
149 		rte_atomic64_add(&count, tmp32);
150 
151 		tmp32 = rte_atomic32_sub_return(&a32, 1);
152 		rte_atomic64_sub(&count, tmp32+1);
153 
154 		tmp64 = rte_atomic64_add_return(&a64, 1);
155 		rte_atomic64_add(&count, tmp64);
156 
157 		tmp64 = rte_atomic64_sub_return(&a64, 1);
158 		rte_atomic64_sub(&count, tmp64+1);
159 	}
160 
161 	return 0;
162 }
163 
164 /*
165  * rte_atomic32_inc_and_test() would increase a 32 bits counter by one and then
166  * test if that counter is equal to 0. It would return true if the counter is 0
167  * and false if the counter is not 0. rte_atomic64_inc_and_test() could do the
168  * same thing but for a 64 bits counter.
169  * Here checks that if the 32/64 bits counter is equal to 0 after being atomically
170  * increased by one. If it is, increase the variable of "count" by one which would
171  * be checked as the result later.
172  *
173  */
174 static int
175 test_atomic_inc_and_test(__attribute__((unused)) void *arg)
176 {
177 	while (rte_atomic32_read(&synchro) == 0)
178 		;
179 
180 	if (rte_atomic16_inc_and_test(&a16)) {
181 		rte_atomic64_inc(&count);
182 	}
183 	if (rte_atomic32_inc_and_test(&a32)) {
184 		rte_atomic64_inc(&count);
185 	}
186 	if (rte_atomic64_inc_and_test(&a64)) {
187 		rte_atomic64_inc(&count);
188 	}
189 
190 	return 0;
191 }
192 
193 /*
194  * rte_atomicXX_dec_and_test() should decrease a 32 bits counter by one and then
195  * test if that counter is equal to 0. It should return true if the counter is 0
196  * and false if the counter is not 0.
197  * This test checks if the counter is equal to 0 after being atomically
198  * decreased by one. If it is, increase the value of "count" by one which is to
199  * be checked as the result later.
200  */
201 static int
202 test_atomic_dec_and_test(__attribute__((unused)) void *arg)
203 {
204 	while (rte_atomic32_read(&synchro) == 0)
205 		;
206 
207 	if (rte_atomic16_dec_and_test(&a16))
208 		rte_atomic64_inc(&count);
209 
210 	if (rte_atomic32_dec_and_test(&a32))
211 		rte_atomic64_inc(&count);
212 
213 	if (rte_atomic64_dec_and_test(&a64))
214 		rte_atomic64_inc(&count);
215 
216 	return 0;
217 }
218 
219 static int
220 test_atomic(void)
221 {
222 	rte_atomic16_init(&a16);
223 	rte_atomic32_init(&a32);
224 	rte_atomic64_init(&a64);
225 	rte_atomic64_init(&count);
226 	rte_atomic32_init(&synchro);
227 
228 	rte_atomic16_set(&a16, 1UL << 10);
229 	rte_atomic32_set(&a32, 1UL << 10);
230 	rte_atomic64_set(&a64, 1ULL << 33);
231 
232 	printf("usual inc/dec/add/sub functions\n");
233 
234 	rte_eal_mp_remote_launch(test_atomic_usual, NULL, SKIP_MASTER);
235 	rte_atomic32_set(&synchro, 1);
236 	rte_eal_mp_wait_lcore();
237 	rte_atomic32_set(&synchro, 0);
238 
239 	if (rte_atomic16_read(&a16) != 1UL << 10) {
240 		printf("Atomic16 usual functions failed\n");
241 		return -1;
242 	}
243 
244 	if (rte_atomic32_read(&a32) != 1UL << 10) {
245 		printf("Atomic32 usual functions failed\n");
246 		return -1;
247 	}
248 
249 	if (rte_atomic64_read(&a64) != 1ULL << 33) {
250 		printf("Atomic64 usual functions failed\n");
251 		return -1;
252 	}
253 
254 	printf("test and set\n");
255 
256 	rte_atomic64_set(&a64, 0);
257 	rte_atomic32_set(&a32, 0);
258 	rte_atomic16_set(&a16, 0);
259 	rte_atomic64_set(&count, 0);
260 	rte_eal_mp_remote_launch(test_atomic_tas, NULL, SKIP_MASTER);
261 	rte_atomic32_set(&synchro, 1);
262 	rte_eal_mp_wait_lcore();
263 	rte_atomic32_set(&synchro, 0);
264 
265 	if (rte_atomic64_read(&count) != NUM_ATOMIC_TYPES) {
266 		printf("Atomic test and set failed\n");
267 		return -1;
268 	}
269 
270 	printf("add/sub and return\n");
271 
272 	rte_atomic64_set(&a64, 0);
273 	rte_atomic32_set(&a32, 0);
274 	rte_atomic16_set(&a16, 0);
275 	rte_atomic64_set(&count, 0);
276 	rte_eal_mp_remote_launch(test_atomic_addsub_and_return, NULL,
277 				 SKIP_MASTER);
278 	rte_atomic32_set(&synchro, 1);
279 	rte_eal_mp_wait_lcore();
280 	rte_atomic32_set(&synchro, 0);
281 
282 	if (rte_atomic64_read(&count) != 0) {
283 		printf("Atomic add/sub+return failed\n");
284 		return -1;
285 	}
286 
287 	/*
288 	 * Set a64, a32 and a16 with the same value of minus "number of slave
289 	 * lcores", launch all slave lcores to atomically increase by one and
290 	 * test them respectively.
291 	 * Each lcore should have only one chance to increase a64 by one and
292 	 * then check if it is equal to 0, but there should be only one lcore
293 	 * that finds that it is 0. It is similar for a32 and a16.
294 	 * Then a variable of "count", initialized to zero, is increased by
295 	 * one if a64, a32 or a16 is 0 after being increased and tested
296 	 * atomically.
297 	 * We can check if "count" is finally equal to 3 to see if all slave
298 	 * lcores performed "atomic inc and test" right.
299 	 */
300 	printf("inc and test\n");
301 
302 	rte_atomic64_clear(&a64);
303 	rte_atomic32_clear(&a32);
304 	rte_atomic16_clear(&a16);
305 	rte_atomic32_clear(&synchro);
306 	rte_atomic64_clear(&count);
307 
308 	rte_atomic64_set(&a64, (int64_t)(1 - (int64_t)rte_lcore_count()));
309 	rte_atomic32_set(&a32, (int32_t)(1 - (int32_t)rte_lcore_count()));
310 	rte_atomic16_set(&a16, (int16_t)(1 - (int16_t)rte_lcore_count()));
311 	rte_eal_mp_remote_launch(test_atomic_inc_and_test, NULL, SKIP_MASTER);
312 	rte_atomic32_set(&synchro, 1);
313 	rte_eal_mp_wait_lcore();
314 	rte_atomic32_clear(&synchro);
315 
316 	if (rte_atomic64_read(&count) != NUM_ATOMIC_TYPES) {
317 		printf("Atomic inc and test failed %d\n", (int)count.cnt);
318 		return -1;
319 	}
320 
321 	/*
322 	 * Same as above, but this time we set the values to "number of slave
323 	 * lcores", and decrement instead of increment.
324 	 */
325 	printf("dec and test\n");
326 
327 	rte_atomic32_clear(&synchro);
328 	rte_atomic64_clear(&count);
329 
330 	rte_atomic64_set(&a64, (int64_t)(rte_lcore_count() - 1));
331 	rte_atomic32_set(&a32, (int32_t)(rte_lcore_count() - 1));
332 	rte_atomic16_set(&a16, (int16_t)(rte_lcore_count() - 1));
333 	rte_eal_mp_remote_launch(test_atomic_dec_and_test, NULL, SKIP_MASTER);
334 	rte_atomic32_set(&synchro, 1);
335 	rte_eal_mp_wait_lcore();
336 	rte_atomic32_clear(&synchro);
337 
338 	if (rte_atomic64_read(&count) != NUM_ATOMIC_TYPES) {
339 		printf("Atomic dec and test failed\n");
340 		return -1;
341 	}
342 
343 	return 0;
344 }
345 
346 REGISTER_TEST_COMMAND(atomic_autotest, test_atomic);
347