tests/test_urcu_fork.c

   1 /*
   2  * test_urcu_fork.c
   3  *
   4  * Userspace RCU library - test program (fork)
   5  *
   6  * Copyright February 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #define _GNU_SOURCE
  24 #include "../config.h"
  25 #include <stdio.h>
  26 #include <pthread.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/types.h>
  30 #include <sys/wait.h>
  31 #include <unistd.h>
  32 #include <stdio.h>
  33 #include <assert.h>
  34 #include <sched.h>
  35 #include <errno.h>
  36
  37 #include <urcu/arch.h>
  38
  39 #ifndef DYNAMIC_LINK_TEST
  40 #define _LGPL_SOURCE
  41 #else
  42 #define rcu_debug_yield_read()
  43 #endif
  44 #include <urcu.h>
  45
  46 struct test_node {
  47         int somedata;
  48         struct rcu_head head;
  49 };
  50
  51 static void cb(struct rcu_head *head)
  52 {
  53         struct test_node *node;
  54
  55         fprintf(stderr, "rcu callback invoked in pid: %d\n",
  56                 (int) getpid());
  57         node = caa_container_of(head, struct test_node, head);
  58         free(node);
  59 }
  60
  61 static void test_rcu(void)
  62 {
  63         struct test_node *node;
  64
  65         rcu_register_thread();
  66
  67         synchronize_rcu();
  68
  69         rcu_read_lock();
  70         rcu_read_unlock();
  71
  72         node = malloc(sizeof(*node));
  73         assert(node);
  74
  75         call_rcu(&node->head, cb);
  76
  77         synchronize_rcu();
  78
  79         rcu_unregister_thread();
  80 }
  81
  82 int main(int argc, char **argv)
  83 {
  84         pid_t pid;
  85         int ret;
  86
  87 #if 0
  88         /* pthread_atfork does not work with malloc/free in callbacks */
  89         ret = pthread_atfork(call_rcu_before_fork,
  90                 call_rcu_after_fork_parent,
  91                 call_rcu_after_fork_child);
  92         if (ret) {
  93                 errno = ret;
  94                 perror("pthread_atfork");
  95                 exit(EXIT_FAILURE);
  96         }
  97 #endif
  98
  99         test_rcu();
 100
 101         synchronize_rcu();
 102
 103         fprintf(stderr, "%s parent pid: %d, before fork\n",
 104                 argv[0], (int) getpid());
 105
 106         call_rcu_before_fork();
 107         pid = fork();
 108
 109         if (pid == 0) {
 110                 /* child */
 111                 call_rcu_after_fork_child();
 112                 fprintf(stderr, "%s child pid: %d, after fork\n",
 113                         argv[0], (int) getpid());
 114                 test_rcu();
 115                 fprintf(stderr, "%s child pid: %d, after rcu test\n",
 116                         argv[0], (int) getpid());
 117         } else if (pid > 0) {
 118                 int status;
 119
 120                 /* parent */
 121                 call_rcu_after_fork_parent();
 122                 fprintf(stderr, "%s parent pid: %d, after fork\n",
 123                         argv[0], (int) getpid());
 124                 test_rcu();
 125                 fprintf(stderr, "%s parent pid: %d, after rcu test\n",
 126                         argv[0], (int) getpid());
 127                 for (;;) {
 128                         pid = wait(&status);
 129                         if (WIFEXITED(status)) {
 130                                 fprintf(stderr, "child %u exited normally with status %u\n",
 131                                         pid, WEXITSTATUS(status));
 132                                 break;
 133                         } else if (WIFSIGNALED(status)) {
 134                                 fprintf(stderr, "child %u was terminated by signal %u\n",
 135                                         pid, WTERMSIG(status));
 136                                 break;
 137                         } else {
 138                                 continue;
 139                         }
 140                 }
 141         } else {
 142                 perror("fork");
 143                 exit(EXIT_FAILURE);
 144         }
 145         exit(EXIT_SUCCESS);
 146 }