close_on_fork.c

   1 /*
   2  * Copyright (C) 2005-2009 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
   9 #include <regex.h>
  10
  11 #include "para.h"
  12 #include "list.h"
  13 #include "string.h"
  14
  15 static struct list_head close_on_fork_list;
  16 static int initialized;
  17
  18 /**
  19  * Describes an element of the close-on-fork list.
  20  *
  21  * \sa list.h
  22  */
  23 struct close_on_fork {
  24         /** The file descriptor which should be closed after fork(). */
  25         int fd;
  26         /** The position in the close-on-fork list. */
  27         struct list_head node;
  28 };
  29
  30 /**
  31  * Add one file descriptor to the close-on-fork list.
  32  *
  33  * \param fd The file descriptor to add.
  34  */
  35 void add_close_on_fork_list(int fd)
  36 {
  37         struct close_on_fork *cof = para_malloc(sizeof(struct close_on_fork));
  38
  39         if (!initialized) {
  40                 INIT_LIST_HEAD(&close_on_fork_list);
  41                 initialized = 1;
  42         }
  43         cof->fd = fd;
  44         para_list_add(&cof->node, &close_on_fork_list);
  45 }
  46
  47 /**
  48  * Delete one file descriptor from the close-on-fork list.
  49  *
  50  * \param fd The file descriptor to delete.
  51  *
  52  * Noop if \a fd does not belong to the close-on-fork list.
  53  */
  54 void del_close_on_fork_list(int fd)
  55 {
  56         struct close_on_fork *cof, *tmp;
  57
  58         if (!initialized)
  59                 return;
  60         list_for_each_entry_safe(cof, tmp, &close_on_fork_list, node) {
  61                 if (fd != cof->fd)
  62                         continue;
  63                 list_del(&cof->node);
  64                 free(cof);
  65         }
  66 }
  67
  68 /**
  69  * Close all fds in the list and destroy all list entries.
  70  *
  71  * This function calls close(3) for each fd in the close-on-fork list
  72  * and empties the list afterwards.
  73  */
  74 void close_listed_fds(void)
  75 {
  76         struct close_on_fork *cof, *tmp;
  77
  78         if (!initialized)
  79                 return;
  80         list_for_each_entry_safe(cof, tmp, &close_on_fork_list, node) {
  81                 PARA_DEBUG_LOG("closing fd %d\n", cof->fd);
  82                 close(cof->fd);
  83                 list_del(&cof->node);
  84                 free(cof);
  85         }
  86 }