doc/examples/wfstack/cds_wfs_pop.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 pop nodes from a wfstack.
   7  */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11
  12 #include <urcu/wfstack.h>       /* Wait-free stack */
  13 #include <urcu/compiler.h>      /* For CAA_ARRAY_SIZE */
  14
  15 /*
  16  * Nodes populated into the stack.
  17  */
  18 struct mynode {
  19         int value;                      /* Node content */
  20         struct cds_wfs_node node;       /* Chaining in stack */
  21 };
  22
  23 int main(void)
  24 {
  25         int values[] = { -5, 42, 36, 24, };
  26         struct cds_wfs_stack mystack;   /* Stack */
  27         unsigned int i;
  28         int ret = 0;
  29
  30         cds_wfs_init(&mystack);
  31
  32         /*
  33          * Push nodes.
  34          */
  35         for (i = 0; i < CAA_ARRAY_SIZE(values); i++) {
  36                 struct mynode *node;
  37
  38                 node = malloc(sizeof(*node));
  39                 if (!node) {
  40                         ret = -1;
  41                         goto end;
  42                 }
  43
  44                 cds_wfs_node_init(&node->node);
  45                 node->value = values[i];
  46                 cds_wfs_push(&mystack, &node->node);
  47         }
  48
  49         /*
  50          * Pop nodes from the stack, one by one, from newest to oldest.
  51          */
  52         printf("pop each mystack node:");
  53         for (;;) {
  54                 struct cds_wfs_node *snode;
  55                 struct mynode *node;
  56
  57                 snode = cds_wfs_pop_blocking(&mystack);
  58                 if (!snode) {
  59                         break;
  60                 }
  61                 node = caa_container_of(snode, struct mynode, node);
  62                 printf(" %d", node->value);
  63                 free(node);
  64         }
  65         printf("\n");
  66 end:
  67         cds_wfs_destroy(&mystack);
  68         return ret;
  69 }