-/*
- * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <inttypes.h>
-
-#include <urcu-qsbr.h> /* QSBR RCU flavor */
-#include <urcu/rculist.h> /* List example */
-#include <urcu/compiler.h> /* For CAA_ARRAY_SIZE */
-
-/*
- * This is a mock-up example where updates and RCU traversals are
- * performed by the same thread to keep things simple on purpose.
- */
-
-static CDS_LIST_HEAD(mylist);
-
-struct mynode {
- uint64_t value;
- struct cds_list_head node; /* linked-list chaining */
- struct rcu_head rcu_head; /* for call_rcu() */
-};
-
-static
-int add_node(uint64_t v)
-{
- struct mynode *node;
-
- node = calloc(sizeof(*node), 1);
- if (!node)
- return -1;
- node->value = v;
- cds_list_add_rcu(&node->node, &mylist);
- return 0;
-}
-
-static
-void rcu_free_node(struct rcu_head *rh)
-{
- struct mynode *node = caa_container_of(rh, struct mynode, rcu_head);
-
- free(node);
-}
-
-int main(int argc, char **argv)
-{
- uint64_t values[] = { 42, 36, 24, };
- unsigned int i;
- int ret;
- struct mynode *node, *n;
-
- /*
- * Each thread need using RCU read-side need to be explicitly
- * registered.
- */
- rcu_register_thread();
-
- /*
- * Adding nodes to the linked-list. Safe against concurrent
- * RCU traversals, require mutual exclusion with list updates.
- */
- for (i = 0; i < CAA_ARRAY_SIZE(values); i++) {
- ret = add_node(values[i]);
- if (ret)
- goto end;
- }
-
- /*
- * For all RCU flavors except QSBR, we need to explicitly mark
- * RCU read-side critical sections with rcu_read_lock() and
- * rcu_read_unlock(). They can be nested. Those are no-ops for
- * the QSBR flavor.
- */
- rcu_read_lock();
-
- /*
- * RCU traversal of the linked list.
- */
- cds_list_for_each_entry_rcu(node, &mylist, node) {
- printf("Value: %" PRIu64 "\n", node->value);
- }
- rcu_read_unlock();
-
- /*
- * Removing nodes from linked list. Safe against concurrent RCU
- * traversals, require mutual exclusion with list updates.
- */
- cds_list_for_each_entry_safe(node, n, &mylist, node) {
- cds_list_del_rcu(&node->node);
- call_rcu(&node->rcu_head, rcu_free_node);
- }
-
- /*
- * For QSBR flavor, we need to explicitly announce quiescent
- * states. Here is how it is done. This should be performed by
- * every online registered RCU threads in the program
- * periodically.
- */
- rcu_quiescent_state();
-
- /*
- * For QSBR flavor, when a thread needs to be in a quiescent
- * state for a long period of time, we use rcu_thread_offline()
- * and rcu_thread_online().
- */
- rcu_thread_offline();
-
- sleep(1);
-
- rcu_thread_online();
-
- /*
- * Waiting for previously called call_rcu handlers to complete
- * before program exits, or in library destructors, is a good
- * practice.
- */
- rcu_barrier();
-
-end:
- rcu_unregister_thread();
- return ret;
-}