| /* |
| * Copyright 2011-2015 Samy Al Bahra. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include <ck_cc.h> |
| #include <ck_sequence.h> |
| #include <errno.h> |
| #include <pthread.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #include "../../common.h" |
| |
| #ifndef STEPS |
| #define STEPS 1000000 |
| #endif |
| |
| struct example { |
| unsigned int a; |
| unsigned int b; |
| unsigned int c; |
| }; |
| |
| static struct example global CK_CC_CACHELINE; |
| static ck_sequence_t seqlock CK_CC_CACHELINE = CK_SEQUENCE_INITIALIZER; |
| static unsigned int barrier; |
| static struct affinity affinerator; |
| |
| static void |
| validate(struct example *copy) |
| { |
| |
| if (copy->b != copy->a + 1000) { |
| ck_error("ERROR: Failed regression: copy->b (%u != %u + %u / %u)\n", |
| copy->b, copy->a, 1000, copy->a + 1000); |
| } |
| |
| if (copy->c != copy->a + copy->b) { |
| ck_error("ERROR: Failed regression: copy->c (%u != %u + %u / %u)\n", |
| copy->c, copy->a, copy->b, copy->a + copy->b); |
| } |
| |
| return; |
| } |
| |
| static void * |
| consumer(void *unused CK_CC_UNUSED) |
| { |
| struct example copy; |
| uint32_t version; |
| unsigned int retries = 0; |
| unsigned int i; |
| |
| unused = NULL; |
| if (aff_iterate(&affinerator)) { |
| perror("ERROR: Could not affine thread"); |
| exit(EXIT_FAILURE); |
| } |
| |
| while (ck_pr_load_uint(&barrier) == 0); |
| for (i = 0; i < STEPS; i++) { |
| /* |
| * Attempt a read of the data structure. If the structure |
| * has been modified between ck_sequence_read_begin and |
| * ck_sequence_read_retry then attempt another read since |
| * the data may be in an inconsistent state. |
| */ |
| do { |
| version = ck_sequence_read_begin(&seqlock); |
| copy.a = ck_pr_load_uint(&global.a); |
| copy.b = ck_pr_load_uint(&global.b); |
| copy.c = ck_pr_load_uint(&global.c); |
| retries++; |
| } while (ck_sequence_read_retry(&seqlock, version) == true); |
| validate(©); |
| |
| CK_SEQUENCE_READ(&seqlock, &version) { |
| copy.a = ck_pr_load_uint(&global.a); |
| copy.b = ck_pr_load_uint(&global.b); |
| copy.c = ck_pr_load_uint(&global.c); |
| retries++; |
| } |
| validate(©); |
| } |
| |
| fprintf(stderr, "%u retries.\n", retries - STEPS); |
| ck_pr_dec_uint(&barrier); |
| return (NULL); |
| } |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| pthread_t *threads; |
| unsigned int counter = 0; |
| bool first = true; |
| int n_threads, i; |
| |
| if (argc != 3) { |
| ck_error("Usage: ck_sequence <number of threads> <affinity delta>\n"); |
| } |
| |
| n_threads = atoi(argv[1]); |
| if (n_threads <= 0) { |
| ck_error("ERROR: Number of threads must be greater than 0\n"); |
| } |
| |
| threads = malloc(sizeof(pthread_t) * n_threads); |
| if (threads == NULL) { |
| ck_error("ERROR: Could not allocate memory for threads\n"); |
| } |
| |
| affinerator.delta = atoi(argv[2]); |
| affinerator.request = 0; |
| |
| for (i = 0; i < n_threads; i++) { |
| if (pthread_create(&threads[i], NULL, consumer, NULL)) { |
| ck_error("ERROR: Failed to create thread %d\n", i); |
| } |
| } |
| |
| for (;;) { |
| /* |
| * Update the shared data in a non-blocking fashion. |
| * If the data is modified by multiple writers then |
| * ck_sequence_write_begin must be called after acquiring |
| * the associated lock and ck_sequence_write_end must be |
| * called before relinquishing the lock. |
| */ |
| ck_sequence_write_begin(&seqlock); |
| global.a = counter++; |
| global.b = global.a + 1000; |
| global.c = global.b + global.a; |
| ck_sequence_write_end(&seqlock); |
| |
| if (first == true) { |
| ck_pr_store_uint(&barrier, n_threads); |
| first = false; |
| } |
| |
| counter++; |
| if (ck_pr_load_uint(&barrier) == 0) |
| break; |
| } |
| |
| printf("%u updates made.\n", counter); |
| return (0); |
| } |
| |