doc/examples/wfstack/cds_wfs_pop.c

   1 /*
   2  * Copyright (C) 2013  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   3  *
   4  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   5  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   6  *
   7  * Permission is hereby granted to use or copy this program for any
   8  * purpose,  provided the above notices are retained on all copies.
   9  * Permission to modify the code and to distribute modified code is
  10  * granted, provided the above notices are retained, and a notice that
  11  * the code was modified is included with the above copyright notice.
  12  *
  13  * This example shows how to pop nodes from a wfstack.
  14  */
  15
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18
  19 #include <urcu/wfstack.h>       /* Wait-free stack */
  20 #include <urcu/compiler.h>      /* For CAA_ARRAY_SIZE */
  21
  22 /*
  23  * Nodes populated into the stack.
  24  */
  25 struct mynode {
  26         int value;                      /* Node content */
  27         struct cds_wfs_node node;       /* Chaining in stack */
  28 };
  29
  30 int main(void)
  31 {
  32         int values[] = { -5, 42, 36, 24, };
  33         struct cds_wfs_stack mystack;   /* Stack */
  34         unsigned int i;
  35         int ret = 0;
  36
  37         cds_wfs_init(&mystack);
  38
  39         /*
  40          * Push nodes.
  41          */
  42         for (i = 0; i < CAA_ARRAY_SIZE(values); i++) {
  43                 struct mynode *node;
  44
  45                 node = malloc(sizeof(*node));
  46                 if (!node) {
  47                         ret = -1;
  48                         goto end;
  49                 }
  50
  51                 cds_wfs_node_init(&node->node);
  52                 node->value = values[i];
  53                 cds_wfs_push(&mystack, &node->node);
  54         }
  55
  56         /*
  57          * Pop nodes from the stack, one by one, from newest to oldest.
  58          */
  59         printf("pop each mystack node:");
  60         for (;;) {
  61                 struct cds_wfs_node *snode;
  62                 struct mynode *node;
  63
  64                 snode = cds_wfs_pop_blocking(&mystack);
  65                 if (!snode) {
  66                         break;
  67                 }
  68                 node = caa_container_of(snode, struct mynode, node);
  69                 printf(" %d", node->value);
  70                 free(node);
  71         }
  72         printf("\n");
  73 end:
  74         cds_wfs_destroy(&mystack);
  75         return ret;
  76 }