doc/examples/wfstack/cds_wfs_pop_all_blocking.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 all 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(int argc, char **argv)
  31 {
  32         int values[] = { -5, 42, 36, 24, };
  33         struct cds_wfs_stack mystack;   /* Stack */
  34         unsigned int i;
  35         int ret = 0;
  36         struct cds_wfs_node *snode, *sn;
  37         struct cds_wfs_head *shead;
  38
  39         cds_wfs_init(&mystack);
  40
  41         /*
  42          * Push nodes.
  43          */
  44         for (i = 0; i < CAA_ARRAY_SIZE(values); i++) {
  45                 struct mynode *node;
  46
  47                 node = malloc(sizeof(*node));
  48                 if (!node) {
  49                         ret = -1;
  50                         goto end;
  51                 }
  52
  53                 cds_wfs_node_init(&node->node);
  54                 node->value = values[i];
  55                 cds_wfs_push(&mystack, &node->node);
  56         }
  57
  58         /*
  59          * Pop all nodes from mystack into shead. The head can the be
  60          * used for iteration.
  61          */
  62         shead = cds_wfs_pop_all_blocking(&mystack);
  63
  64         /*
  65          * Show the stack content, iterate in reverse order of push,
  66          * from newest to oldest. Use cds_wfs_for_each_blocking_safe()
  67          * so we can free the nodes as we iterate.
  68          */
  69         printf("mystack content:");
  70         cds_wfs_for_each_blocking_safe(shead, snode, sn) {
  71                 struct mynode *node =
  72                         caa_container_of(snode, struct mynode, node);
  73                 printf(" %d", node->value);
  74                 free(node);
  75         }
  76         printf("\n");
  77 end:
  78         return ret;
  79 }