| 1 | // SPDX-FileCopyrightText: 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 2 | // |
| 3 | // SPDX-License-Identifier: MIT |
| 4 | |
| 5 | /* |
| 6 | * This example shows how to splice nodes from a source wfcqueue A into |
| 7 | * a destination wfcqueue B. |
| 8 | */ |
| 9 | |
| 10 | #include <stdio.h> |
| 11 | #include <stdlib.h> |
| 12 | |
| 13 | #include <urcu/wfcqueue.h> /* Wait-free concurrent queue */ |
| 14 | #include <urcu/compiler.h> /* For CAA_ARRAY_SIZE */ |
| 15 | |
| 16 | /* |
| 17 | * Nodes populated into the queue. |
| 18 | */ |
| 19 | struct mynode { |
| 20 | int value; /* Node content */ |
| 21 | struct cds_wfcq_node node; /* Chaining in queue */ |
| 22 | }; |
| 23 | |
| 24 | static |
| 25 | int enqueue_values(struct cds_wfcq_head *head, |
| 26 | struct cds_wfcq_tail *tail, |
| 27 | int *values, |
| 28 | size_t nr_values) |
| 29 | { |
| 30 | int ret = 0; |
| 31 | unsigned int i; |
| 32 | |
| 33 | for (i = 0; i < nr_values; i++) { |
| 34 | struct mynode *node; |
| 35 | |
| 36 | node = malloc(sizeof(*node)); |
| 37 | if (!node) { |
| 38 | ret = -1; |
| 39 | goto end; |
| 40 | } |
| 41 | cds_wfcq_node_init(&node->node); |
| 42 | node->value = values[i]; |
| 43 | cds_wfcq_enqueue(head, tail, &node->node); |
| 44 | } |
| 45 | end: |
| 46 | return ret; |
| 47 | } |
| 48 | |
| 49 | static |
| 50 | void print_queue(struct cds_wfcq_head *head, |
| 51 | struct cds_wfcq_tail *tail, |
| 52 | const char *qname) |
| 53 | { |
| 54 | struct cds_wfcq_node *qnode; |
| 55 | |
| 56 | printf("%s:", qname); |
| 57 | __cds_wfcq_for_each_blocking(head, tail, qnode) { |
| 58 | struct mynode *node = |
| 59 | caa_container_of(qnode, struct mynode, node); |
| 60 | printf(" %d", node->value); |
| 61 | } |
| 62 | printf("\n"); |
| 63 | } |
| 64 | |
| 65 | int main(void) |
| 66 | { |
| 67 | int values_A[] = { -5, 42, 36, 24, }; |
| 68 | int values_B[] = { 200, 300, 400, }; |
| 69 | struct cds_wfcq_head head_A; /* Queue A head */ |
| 70 | struct cds_wfcq_tail tail_A; /* Queue A tail */ |
| 71 | struct cds_wfcq_head head_B; /* Queue B head */ |
| 72 | struct cds_wfcq_tail tail_B; /* Queue B tail */ |
| 73 | int ret = 0; |
| 74 | |
| 75 | cds_wfcq_init(&head_A, &tail_A); |
| 76 | /* Enqueue nodes into A. */ |
| 77 | ret = enqueue_values(&head_A, &tail_A, values_A, |
| 78 | CAA_ARRAY_SIZE(values_A)); |
| 79 | if (ret) |
| 80 | goto end; |
| 81 | cds_wfcq_init(&head_B, &tail_B); |
| 82 | /* Enqueue nodes into B. */ |
| 83 | ret = enqueue_values(&head_B, &tail_B, values_B, |
| 84 | CAA_ARRAY_SIZE(values_B)); |
| 85 | if (ret) |
| 86 | goto end; |
| 87 | |
| 88 | print_queue(&head_A, &tail_A, "queue A content before splice"); |
| 89 | print_queue(&head_B, &tail_B, "queue B content before splice"); |
| 90 | |
| 91 | /* |
| 92 | * Splice nodes from A into B. |
| 93 | */ |
| 94 | printf("Splicing queue A into queue B\n"); |
| 95 | (void) cds_wfcq_splice_blocking(&head_B, &tail_B, |
| 96 | &head_A, &tail_A); |
| 97 | |
| 98 | print_queue(&head_A, &tail_A, "queue A content after splice"); |
| 99 | print_queue(&head_B, &tail_B, "queue B content after splice"); |
| 100 | end: |
| 101 | cds_wfcq_destroy(&head_A, &tail_A); |
| 102 | return ret; |
| 103 | } |