xref: /dpdk/app/test/test_atomic.c (revision e9d48c0072d36eb6423b45fba4ec49d0def6c36f)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
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10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
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18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <stdio.h>
35 #include <stdint.h>
36 #include <unistd.h>
37 #include <sys/queue.h>
38 
39 #include <cmdline_parse.h>
40 
41 #include <rte_memory.h>
42 #include <rte_memzone.h>
43 #include <rte_per_lcore.h>
44 #include <rte_launch.h>
45 #include <rte_atomic.h>
46 #include <rte_tailq.h>
47 #include <rte_eal.h>
48 #include <rte_per_lcore.h>
49 #include <rte_lcore.h>
50 
51 #include "test.h"
52 
53 /*
54  * Atomic Variables
55  * ================
56  *
57  * - The main test function performs three subtests. The first test
58  *   checks that the usual inc/dec/add/sub functions are working
59  *   correctly:
60  *
61  *   - Initialize 16-bit, 32-bit and 64-bit atomic variables to specific
62  *     values.
63  *
64  *   - These variables are incremented and decremented on each core at
65  *     the same time in ``test_atomic_usual()``.
66  *
67  *   - The function checks that once all lcores finish their function,
68  *     the value of the atomic variables are still the same.
69  *
70  * - The second test verifies the behavior of "test and set" functions.
71  *
72  *   - Initialize 16-bit, 32-bit and 64-bit atomic variables to zero.
73  *
74  *   - Invoke ``test_atomic_tas()`` on each lcore: before doing anything
75  *     else. The cores are waiting a synchro using ``while
76  *     (rte_atomic32_read(&val) == 0)`` which is triggered by the main test
77  *     function. Then all cores do a
78  *     ``rte_atomicXX_test_and_set()`` at the same time. If it is successful,
79  *     it increments another atomic counter.
80  *
81  *   - The main function checks that the atomic counter was incremented
82  *     twice only (one for 16-bit, one for 32-bit and one for 64-bit values).
83  *
84  * - Test "add/sub and return"
85  *
86  *   - Initialize 16-bit, 32-bit and 64-bit atomic variables to zero.
87  *
88  *   - Invoke ``test_atomic_addsub_return()`` on each lcore. Before doing
89  *     anything else, the cores are waiting a synchro. Each lcore does
90  *     this operation several times::
91  *
92  *       tmp = rte_atomicXX_add_return(&a, 1);
93  *       atomic_add(&count, tmp);
94  *       tmp = rte_atomicXX_sub_return(&a, 1);
95  *       atomic_sub(&count, tmp+1);
96  *
97  *   - At the end of the test, the *count* value must be 0.
98  */
99 
100 #define NUM_ATOMIC_TYPES 3
101 
102 #define N 10000
103 
104 static rte_atomic16_t a16;
105 static rte_atomic32_t a32;
106 static rte_atomic64_t a64;
107 static rte_atomic64_t count;
108 static rte_atomic32_t synchro;
109 
110 static int
111 test_atomic_usual(__attribute__((unused)) void *arg)
112 {
113 	unsigned i;
114 
115 	while (rte_atomic32_read(&synchro) == 0)
116 		;
117 
118 	for (i = 0; i < N; i++)
119 		rte_atomic16_inc(&a16);
120 	for (i = 0; i < N; i++)
121 		rte_atomic16_dec(&a16);
122 	for (i = 0; i < (N / 5); i++)
123 		rte_atomic16_add(&a16, 5);
124 	for (i = 0; i < (N / 5); i++)
125 		rte_atomic16_sub(&a16, 5);
126 
127 	for (i = 0; i < N; i++)
128 		rte_atomic32_inc(&a32);
129 	for (i = 0; i < N; i++)
130 		rte_atomic32_dec(&a32);
131 	for (i = 0; i < (N / 5); i++)
132 		rte_atomic32_add(&a32, 5);
133 	for (i = 0; i < (N / 5); i++)
134 		rte_atomic32_sub(&a32, 5);
135 
136 	for (i = 0; i < N; i++)
137 		rte_atomic64_inc(&a64);
138 	for (i = 0; i < N; i++)
139 		rte_atomic64_dec(&a64);
140 	for (i = 0; i < (N / 5); i++)
141 		rte_atomic64_add(&a64, 5);
142 	for (i = 0; i < (N / 5); i++)
143 		rte_atomic64_sub(&a64, 5);
144 
145 	return 0;
146 }
147 
148 static int
149 test_atomic_tas(__attribute__((unused)) void *arg)
150 {
151 	while (rte_atomic32_read(&synchro) == 0)
152 		;
153 
154 	if (rte_atomic16_test_and_set(&a16))
155 		rte_atomic64_inc(&count);
156 	if (rte_atomic32_test_and_set(&a32))
157 		rte_atomic64_inc(&count);
158 	if (rte_atomic64_test_and_set(&a64))
159 		rte_atomic64_inc(&count);
160 
161 	return 0;
162 }
163 
164 static int
165 test_atomic_addsub_and_return(__attribute__((unused)) void *arg)
166 {
167 	uint32_t tmp16;
168 	uint32_t tmp32;
169 	uint64_t tmp64;
170 	unsigned i;
171 
172 	while (rte_atomic32_read(&synchro) == 0)
173 		;
174 
175 	for (i = 0; i < N; i++) {
176 		tmp16 = rte_atomic16_add_return(&a16, 1);
177 		rte_atomic64_add(&count, tmp16);
178 
179 		tmp16 = rte_atomic16_sub_return(&a16, 1);
180 		rte_atomic64_sub(&count, tmp16+1);
181 
182 		tmp32 = rte_atomic32_add_return(&a32, 1);
183 		rte_atomic64_add(&count, tmp32);
184 
185 		tmp32 = rte_atomic32_sub_return(&a32, 1);
186 		rte_atomic64_sub(&count, tmp32+1);
187 
188 		tmp64 = rte_atomic64_add_return(&a64, 1);
189 		rte_atomic64_add(&count, tmp64);
190 
191 		tmp64 = rte_atomic64_sub_return(&a64, 1);
192 		rte_atomic64_sub(&count, tmp64+1);
193 	}
194 
195 	return 0;
196 }
197 
198 /*
199  * rte_atomic32_inc_and_test() would increase a 32 bits counter by one and then
200  * test if that counter is equal to 0. It would return true if the counter is 0
201  * and false if the counter is not 0. rte_atomic64_inc_and_test() could do the
202  * same thing but for a 64 bits counter.
203  * Here checks that if the 32/64 bits counter is equal to 0 after being atomically
204  * increased by one. If it is, increase the variable of "count" by one which would
205  * be checked as the result later.
206  *
207  */
208 static int
209 test_atomic_inc_and_test(__attribute__((unused)) void *arg)
210 {
211 	while (rte_atomic32_read(&synchro) == 0)
212 		;
213 
214 	if (rte_atomic16_inc_and_test(&a16)) {
215 		rte_atomic64_inc(&count);
216 	}
217 	if (rte_atomic32_inc_and_test(&a32)) {
218 		rte_atomic64_inc(&count);
219 	}
220 	if (rte_atomic64_inc_and_test(&a64)) {
221 		rte_atomic64_inc(&count);
222 	}
223 
224 	return 0;
225 }
226 
227 /*
228  * rte_atomicXX_dec_and_test() should decrease a 32 bits counter by one and then
229  * test if that counter is equal to 0. It should return true if the counter is 0
230  * and false if the counter is not 0.
231  * This test checks if the counter is equal to 0 after being atomically
232  * decreased by one. If it is, increase the value of "count" by one which is to
233  * be checked as the result later.
234  */
235 static int
236 test_atomic_dec_and_test(__attribute__((unused)) void *arg)
237 {
238 	while (rte_atomic32_read(&synchro) == 0)
239 		;
240 
241 	if (rte_atomic16_dec_and_test(&a16))
242 		rte_atomic64_inc(&count);
243 
244 	if (rte_atomic32_dec_and_test(&a32))
245 		rte_atomic64_inc(&count);
246 
247 	if (rte_atomic64_dec_and_test(&a64))
248 		rte_atomic64_inc(&count);
249 
250 	return 0;
251 }
252 
253 int
254 test_atomic(void)
255 {
256 	rte_atomic16_init(&a16);
257 	rte_atomic32_init(&a32);
258 	rte_atomic64_init(&a64);
259 	rte_atomic64_init(&count);
260 	rte_atomic32_init(&synchro);
261 
262 	rte_atomic16_set(&a16, 1UL << 10);
263 	rte_atomic32_set(&a32, 1UL << 10);
264 	rte_atomic64_set(&a64, 1ULL << 33);
265 
266 	printf("usual inc/dec/add/sub functions\n");
267 
268 	rte_eal_mp_remote_launch(test_atomic_usual, NULL, SKIP_MASTER);
269 	rte_atomic32_set(&synchro, 1);
270 	rte_eal_mp_wait_lcore();
271 	rte_atomic32_set(&synchro, 0);
272 
273 	if (rte_atomic16_read(&a16) != 1UL << 10) {
274 		printf("Atomic16 usual functions failed\n");
275 		return -1;
276 	}
277 
278 	if (rte_atomic32_read(&a32) != 1UL << 10) {
279 		printf("Atomic32 usual functions failed\n");
280 		return -1;
281 	}
282 
283 	if (rte_atomic64_read(&a64) != 1ULL << 33) {
284 		printf("Atomic64 usual functions failed\n");
285 		return -1;
286 	}
287 
288 	printf("test and set\n");
289 
290 	rte_atomic64_set(&a64, 0);
291 	rte_atomic32_set(&a32, 0);
292 	rte_atomic16_set(&a16, 0);
293 	rte_atomic64_set(&count, 0);
294 	rte_eal_mp_remote_launch(test_atomic_tas, NULL, SKIP_MASTER);
295 	rte_atomic32_set(&synchro, 1);
296 	rte_eal_mp_wait_lcore();
297 	rte_atomic32_set(&synchro, 0);
298 
299 	if (rte_atomic64_read(&count) != NUM_ATOMIC_TYPES) {
300 		printf("Atomic test and set failed\n");
301 		return -1;
302 	}
303 
304 	printf("add/sub and return\n");
305 
306 	rte_atomic64_set(&a64, 0);
307 	rte_atomic32_set(&a32, 0);
308 	rte_atomic16_set(&a16, 0);
309 	rte_atomic64_set(&count, 0);
310 	rte_eal_mp_remote_launch(test_atomic_addsub_and_return, NULL,
311 				 SKIP_MASTER);
312 	rte_atomic32_set(&synchro, 1);
313 	rte_eal_mp_wait_lcore();
314 	rte_atomic32_set(&synchro, 0);
315 
316 	if (rte_atomic64_read(&count) != 0) {
317 		printf("Atomic add/sub+return failed\n");
318 		return -1;
319 	}
320 
321 	/*
322 	 * Set a64, a32 and a16 with the same value of minus "number of slave
323 	 * lcores", launch all slave lcores to atomically increase by one and
324 	 * test them respectively.
325 	 * Each lcore should have only one chance to increase a64 by one and
326 	 * then check if it is equal to 0, but there should be only one lcore
327 	 * that finds that it is 0. It is similar for a32 and a16.
328 	 * Then a variable of "count", initialized to zero, is increased by
329 	 * one if a64, a32 or a16 is 0 after being increased and tested
330 	 * atomically.
331 	 * We can check if "count" is finally equal to 3 to see if all slave
332 	 * lcores performed "atomic inc and test" right.
333 	 */
334 	printf("inc and test\n");
335 
336 	rte_atomic64_clear(&a64);
337 	rte_atomic32_clear(&a32);
338 	rte_atomic16_clear(&a16);
339 	rte_atomic32_clear(&synchro);
340 	rte_atomic64_clear(&count);
341 
342 	rte_atomic64_set(&a64, (int64_t)(1 - (int64_t)rte_lcore_count()));
343 	rte_atomic32_set(&a32, (int32_t)(1 - (int32_t)rte_lcore_count()));
344 	rte_atomic16_set(&a16, (int16_t)(1 - (int16_t)rte_lcore_count()));
345 	rte_eal_mp_remote_launch(test_atomic_inc_and_test, NULL, SKIP_MASTER);
346 	rte_atomic32_set(&synchro, 1);
347 	rte_eal_mp_wait_lcore();
348 	rte_atomic32_clear(&synchro);
349 
350 	if (rte_atomic64_read(&count) != NUM_ATOMIC_TYPES) {
351 		printf("Atomic inc and test failed %d\n", (int)count.cnt);
352 		return -1;
353 	}
354 
355 	/*
356 	 * Same as above, but this time we set the values to "number of slave
357 	 * lcores", and decrement instead of increment.
358 	 */
359 	printf("dec and test\n");
360 
361 	rte_atomic32_clear(&synchro);
362 	rte_atomic64_clear(&count);
363 
364 	rte_atomic64_set(&a64, (int64_t)(rte_lcore_count() - 1));
365 	rte_atomic32_set(&a32, (int32_t)(rte_lcore_count() - 1));
366 	rte_atomic16_set(&a16, (int16_t)(rte_lcore_count() - 1));
367 	rte_eal_mp_remote_launch(test_atomic_dec_and_test, NULL, SKIP_MASTER);
368 	rte_atomic32_set(&synchro, 1);
369 	rte_eal_mp_wait_lcore();
370 	rte_atomic32_clear(&synchro);
371 
372 	if (rte_atomic64_read(&count) != NUM_ATOMIC_TYPES) {
373 		printf("Atomic dec and test failed\n");
374 		return -1;
375 	}
376 
377 	return 0;
378 }
379 
380