tests/regression/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 #include <urcu/tls-compat.h>
  39
  40 #ifndef DYNAMIC_LINK_TEST
  41 #define _LGPL_SOURCE
  42 #else
  43 #define rcu_debug_yield_read()
  44 #endif
  45 #include <urcu.h>
  46
  47 /* We generate children 3 levels deep */
  48 #define FORK_DEPTH      3
  49 /* Each generation spawns 10 children */
  50 #define NR_FORK         10
  51
  52 static int fork_generation;
  53
  54 struct test_node {
  55         int somedata;
  56         struct rcu_head head;
  57 };
  58
  59 static void cb(struct rcu_head *head)
  60 {
  61         struct test_node *node;
  62
  63         fprintf(stderr, "rcu callback invoked in pid: %d\n",
  64                 (int) getpid());
  65         node = caa_container_of(head, struct test_node, head);
  66         free(node);
  67 }
  68
  69 static void test_rcu(void)
  70 {
  71         struct test_node *node;
  72
  73         rcu_register_thread();
  74
  75         synchronize_rcu();
  76
  77         rcu_read_lock();
  78         rcu_read_unlock();
  79
  80         node = malloc(sizeof(*node));
  81         assert(node);
  82
  83         call_rcu(&node->head, cb);
  84
  85         synchronize_rcu();
  86
  87         rcu_unregister_thread();
  88 }
  89
  90 /*
  91  * Return 0 if child, > 0 if parent, < 0 on error.
  92  */
  93 static int do_fork(const char *execname)
  94 {
  95         pid_t pid;
  96
  97         fprintf(stderr, "%s parent pid: %d, before fork\n",
  98                 execname, (int) getpid());
  99
 100         call_rcu_before_fork();
 101         pid = fork();
 102         if (pid == 0) {
 103                 /* child */
 104                 fork_generation++;
 105
 106                 call_rcu_after_fork_child();
 107                 fprintf(stderr, "%s child pid: %d, after fork\n",
 108                         execname, (int) getpid());
 109                 test_rcu();
 110                 fprintf(stderr, "%s child pid: %d, after rcu test\n",
 111                         execname, (int) getpid());
 112                 if (fork_generation >= FORK_DEPTH)
 113                         exit(EXIT_SUCCESS);
 114                 return 0;
 115         } else if (pid > 0) {
 116                 int status;
 117
 118                 /* parent */
 119                 call_rcu_after_fork_parent();
 120                 fprintf(stderr, "%s parent pid: %d, after fork\n",
 121                         execname, (int) getpid());
 122                 test_rcu();
 123                 fprintf(stderr, "%s parent pid: %d, after rcu test\n",
 124                         execname, (int) getpid());
 125                 for (;;) {
 126                         pid = wait(&status);
 127                         if (pid < 0) {
 128                                 perror("wait");
 129                                 return -1;
 130                         }
 131                         if (WIFEXITED(status)) {
 132                                 fprintf(stderr, "child %u exited normally with status %u\n",
 133                                         pid, WEXITSTATUS(status));
 134                                 if (WEXITSTATUS(status))
 135                                         return -1;
 136                                 break;
 137                         } else if (WIFSIGNALED(status)) {
 138                                 fprintf(stderr, "child %u was terminated by signal %u\n",
 139                                         pid, WTERMSIG(status));
 140                                 return -1;
 141                         } else {
 142                                 continue;
 143                         }
 144                 }
 145                 return 1;
 146         } else {
 147                 perror("fork");
 148                 return -1;
 149         }
 150 }
 151
 152 int main(int argc, char **argv)
 153 {
 154         unsigned int i;
 155
 156 #if 0
 157         /* pthread_atfork does not work with malloc/free in callbacks */
 158         ret = pthread_atfork(call_rcu_before_fork,
 159                 call_rcu_after_fork_parent,
 160                 call_rcu_after_fork_child);
 161         if (ret) {
 162                 errno = ret;
 163                 perror("pthread_atfork");
 164                 exit(EXIT_FAILURE);
 165         }
 166 #endif
 167
 168 restart:
 169         for (i = 0; i < NR_FORK; i++) {
 170                 int ret;
 171
 172                 test_rcu();
 173                 synchronize_rcu();
 174                 ret = do_fork(argv[0]);
 175                 if (ret == 0)           /* child */
 176                         goto restart;
 177                 else if (ret < 0)
 178                         goto error;
 179                 /* else parent, continue. */
 180         }
 181         exit(EXIT_SUCCESS);
 182
 183 error:
 184         exit(EXIT_FAILURE);
 185 }