doc/examples/wfcqueue/cds_wfcq_enqueue.c

   1 // SPDX-FileCopyrightText: 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   2 //
   3 // SPDX-License-Identifier: MIT
   4
   5 /*
   6  * This example shows how to enqueue nodes into a wfcqueue.
   7  */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11
  12 #include <urcu/wfcqueue.h>      /* Wait-free concurrent queue */
  13 #include <urcu/compiler.h>      /* For CAA_ARRAY_SIZE */
  14
  15 /*
  16  * Nodes populated into the queue.
  17  */
  18 struct mynode {
  19         int value;                      /* Node content */
  20         struct cds_wfcq_node node;      /* Chaining in queue */
  21 };
  22
  23 int main(void)
  24 {
  25         int values[] = { -5, 42, 36, 24, };
  26         struct cds_wfcq_head myqueue_head;      /* Queue head */
  27         struct cds_wfcq_tail myqueue_tail;      /* Queue tail */
  28         unsigned int i;
  29         int ret = 0;
  30         struct cds_wfcq_node *qnode;
  31
  32         cds_wfcq_init(&myqueue_head, &myqueue_tail);
  33
  34         /*
  35          * Enqueue nodes.
  36          */
  37         for (i = 0; i < CAA_ARRAY_SIZE(values); i++) {
  38                 struct mynode *node;
  39
  40                 node = malloc(sizeof(*node));
  41                 if (!node) {
  42                         ret = -1;
  43                         goto end;
  44                 }
  45
  46                 cds_wfcq_node_init(&node->node);
  47                 node->value = values[i];
  48                 cds_wfcq_enqueue(&myqueue_head, &myqueue_tail,
  49                                 &node->node);
  50         }
  51
  52         /*
  53          * Show the queue content, iterate in the same order nodes were
  54          * enqueued, from oldest to newest.
  55          */
  56         printf("myqueue content:");
  57         __cds_wfcq_for_each_blocking(&myqueue_head, &myqueue_tail, qnode) {
  58                 struct mynode *node =
  59                         caa_container_of(qnode, struct mynode, node);
  60                 printf(" %d", node->value);
  61         }
  62         printf("\n");
  63 end:
  64         cds_wfcq_destroy(&myqueue_head, &myqueue_tail);
  65         return ret;
  66 }