close_on_fork.c

   1 /*
   2  * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file close_on_fork.c manage a list of fds that should be closed on fork */
   8 #include "para.h"
   9 #include "list.h"
  10 #include "string.h"
  11
  12 static struct list_head close_on_fork_list;
  13 static int initialized;
  14
  15 /**
  16  * describes an element of the close-on-fork list
  17  *
  18  * \sa list.h
  19  */
  20 struct close_on_fork {
  21         /** the file descriptor which should be closed after fork() */
  22         int fd;
  23         /** the position in the close-on-fork list */
  24         struct list_head node;
  25 };
  26
  27 /**
  28  * add one file descriptor to the close-on-fork list
  29  *
  30  * \param fd the file descriptor to add
  31  */
  32 void add_close_on_fork_list(int fd)
  33 {
  34         struct close_on_fork *cof = para_malloc(sizeof(struct close_on_fork));
  35
  36         if (!initialized) {
  37                 INIT_LIST_HEAD(&close_on_fork_list);
  38                 initialized = 1;
  39         }
  40         cof->fd = fd;
  41         para_list_add(&cof->node, &close_on_fork_list);
  42 }
  43
  44
  45 /**
  46  * delete one file descriptor from the close-on-fork list
  47  *
  48  * \param fd the file descriptor to delete
  49  *
  50  * Noop if \a fd does not belong to the close-on-fork list.
  51  */
  52 void del_close_on_fork_list(int fd)
  53 {
  54         struct close_on_fork *cof, *tmp;
  55
  56         if (!initialized)
  57                 return;
  58         list_for_each_entry_safe(cof, tmp, &close_on_fork_list, node) {
  59                 if (fd != cof->fd)
  60                         continue;
  61                 list_del(&cof->node);
  62                 free(cof);
  63         }
  64 }
  65
  66 /**
  67  * call close(3) for each fd in the close-on-fork list
  68  */
  69 void close_listed_fds(void)
  70 {
  71         struct close_on_fork *cof;
  72
  73         if (!initialized)
  74                 return;
  75         list_for_each_entry(cof, &close_on_fork_list, node) {
  76                 PARA_DEBUG_LOG("closing fd %d\n", cof->fd);
  77                 close(cof->fd);
  78         }
  79 }