--- /dev/null
+/*
+ * test_urcu_fork.c
+ *
+ * Userspace RCU library - test program (fork)
+ *
+ * Copyright February 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _GNU_SOURCE
+#include "config.h"
+#include <stdio.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <assert.h>
+#include <sched.h>
+#include <errno.h>
+
+#include <urcu/arch.h>
+#include <urcu/tls-compat.h>
+
+#ifndef DYNAMIC_LINK_TEST
+#define _LGPL_SOURCE
+#else
+#define rcu_debug_yield_read()
+#endif
+#include <urcu.h>
+
+/* We generate children 3 levels deep */
+#define FORK_DEPTH 3
+/* Each generation spawns 10 children */
+#define NR_FORK 10
+
+static int fork_generation;
+
+struct test_node {
+ int somedata;
+ struct rcu_head head;
+};
+
+static void cb(struct rcu_head *head)
+{
+ struct test_node *node;
+
+ fprintf(stderr, "rcu callback invoked in pid: %d\n",
+ (int) getpid());
+ node = caa_container_of(head, struct test_node, head);
+ free(node);
+}
+
+static void test_rcu(void)
+{
+ struct test_node *node;
+
+ rcu_register_thread();
+
+ synchronize_rcu();
+
+ rcu_read_lock();
+ rcu_read_unlock();
+
+ node = malloc(sizeof(*node));
+ assert(node);
+
+ call_rcu(&node->head, cb);
+
+ synchronize_rcu();
+
+ rcu_unregister_thread();
+}
+
+/*
+ * Return 0 if child, > 0 if parent, < 0 on error.
+ */
+static int do_fork(const char *execname)
+{
+ pid_t pid;
+
+ fprintf(stderr, "%s parent pid: %d, before fork\n",
+ execname, (int) getpid());
+
+ call_rcu_before_fork();
+ pid = fork();
+ if (pid == 0) {
+ /* child */
+ fork_generation++;
+
+ call_rcu_after_fork_child();
+ fprintf(stderr, "%s child pid: %d, after fork\n",
+ execname, (int) getpid());
+ test_rcu();
+ fprintf(stderr, "%s child pid: %d, after rcu test\n",
+ execname, (int) getpid());
+ if (fork_generation >= FORK_DEPTH)
+ exit(EXIT_SUCCESS);
+ return 0;
+ } else if (pid > 0) {
+ int status;
+
+ /* parent */
+ call_rcu_after_fork_parent();
+ fprintf(stderr, "%s parent pid: %d, after fork\n",
+ execname, (int) getpid());
+ test_rcu();
+ fprintf(stderr, "%s parent pid: %d, after rcu test\n",
+ execname, (int) getpid());
+ for (;;) {
+ pid = wait(&status);
+ if (pid < 0) {
+ perror("wait");
+ return -1;
+ }
+ if (WIFEXITED(status)) {
+ fprintf(stderr, "child %u exited normally with status %u\n",
+ pid, WEXITSTATUS(status));
+ if (WEXITSTATUS(status))
+ return -1;
+ break;
+ } else if (WIFSIGNALED(status)) {
+ fprintf(stderr, "child %u was terminated by signal %u\n",
+ pid, WTERMSIG(status));
+ return -1;
+ } else {
+ continue;
+ }
+ }
+ return 1;
+ } else {
+ perror("fork");
+ return -1;
+ }
+}
+
+int main(int argc, char **argv)
+{
+ unsigned int i;
+
+#if 0
+ /* pthread_atfork does not work with malloc/free in callbacks */
+ ret = pthread_atfork(call_rcu_before_fork,
+ call_rcu_after_fork_parent,
+ call_rcu_after_fork_child);
+ if (ret) {
+ errno = ret;
+ perror("pthread_atfork");
+ exit(EXIT_FAILURE);
+ }
+#endif
+
+restart:
+ for (i = 0; i < NR_FORK; i++) {
+ int ret;
+
+ test_rcu();
+ synchronize_rcu();
+ ret = do_fork(argv[0]);
+ if (ret == 0) /* child */
+ goto restart;
+ else if (ret < 0)
+ goto error;
+ /* else parent, continue. */
+ }
+ exit(EXIT_SUCCESS);
+
+error:
+ exit(EXIT_FAILURE);
+}