linuxthreads/ptfork.c

   1 /* Linuxthreads - a simple clone()-based implementation of Posix        */
   2 /* threads for Linux.                                                   */
   3 /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */
   4 /*                                                                      */
   5 /* This program is free software; you can redistribute it and/or        */
   6 /* modify it under the terms of the GNU Library General Public License  */
   7 /* as published by the Free Software Foundation; either version 2       */
   8 /* of the License, or (at your option) any later version.               */
   9 /*                                                                      */
  10 /* This program is distributed in the hope that it will be useful,      */
  11 /* but WITHOUT ANY WARRANTY; without even the implied warranty of       */
  12 /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        */
  13 /* GNU Library General Public License for more details.                 */
  14
  15 /* The "atfork" stuff */
  16
  17 #include <errno.h>
  18 #include <stddef.h>
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21 #include "pthread.h"
  22 #include "internals.h"
  23 #include <bits/libc-lock.h>
  24 #include "fork.h"
  25
  26 extern int __libc_fork (void);
  27
  28 pid_t __pthread_fork (struct fork_block *b)
  29 {
  30   pid_t pid;
  31   list_t *runp;
  32
  33   __libc_lock_lock (b->lock);
  34
  35   /* Run all the registered preparation handlers.  In reverse order.  */
  36   list_for_each_prev (runp, &b->prepare_list)
  37     {
  38       struct fork_handler *curp;
  39       curp = list_entry (runp, struct fork_handler, list);
  40       curp->handler ();
  41     }
  42
  43   __pthread_once_fork_prepare();
  44   __flockfilelist();
  45
  46   pid = ARCH_FORK ();
  47
  48   if (pid == 0) {
  49     __pthread_reset_main_thread();
  50
  51     __fresetlockfiles();
  52     __pthread_once_fork_child();
  53
  54     /* Run the handlers registered for the child.  */
  55     list_for_each (runp, &b->child_list)
  56       {
  57         struct fork_handler *curp;
  58         curp = list_entry (runp, struct fork_handler, list);
  59         curp->handler ();
  60       }
  61
  62     __libc_lock_init (b->lock);
  63   } else {
  64     __funlockfilelist();
  65     __pthread_once_fork_parent();
  66
  67     /* Run the handlers registered for the parent.  */
  68     list_for_each (runp, &b->parent_list)
  69       {
  70         struct fork_handler *curp;
  71         curp = list_entry (runp, struct fork_handler, list);
  72         curp->handler ();
  73       }
  74
  75     __libc_lock_unlock (b->lock);
  76   }
  77
  78   return pid;
  79 }
  80
  81 #ifdef SHARED
  82 pid_t __fork (void)
  83 {
  84   return __libc_fork ();
  85 }
  86 weak_alias (__fork, fork);
  87
  88 pid_t __vfork(void)
  89 {
  90   return __libc_fork ();
  91 }
  92 weak_alias (__vfork, vfork);
  93 #endif