close_on_fork.c

   1 /*
   2  * Copyright (C) 2005-2014 Andre Noll <maan@tuebingen.mpg.de>
   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 #include "close_on_fork.h"
  15
  16 static struct list_head close_on_fork_list;
  17 static int initialized;
  18
  19 /**
  20  * Describes an element of the close-on-fork list.
  21  *
  22  * \sa list.h
  23  */
  24 struct close_on_fork {
  25         /** The file descriptor which should be closed after fork(). */
  26         int fd;
  27         /** The position in the close-on-fork list. */
  28         struct list_head node;
  29 };
  30
  31 /**
  32  * Add one file descriptor to the close-on-fork list.
  33  *
  34  * \param fd The file descriptor to add.
  35  */
  36 void add_close_on_fork_list(int fd)
  37 {
  38         struct close_on_fork *cof = para_malloc(sizeof(struct close_on_fork));
  39
  40         if (!initialized) {
  41                 INIT_LIST_HEAD(&close_on_fork_list);
  42                 initialized = 1;
  43         }
  44         cof->fd = fd;
  45         para_list_add(&cof->node, &close_on_fork_list);
  46 }
  47
  48 /**
  49  * Delete one file descriptor from the close-on-fork list.
  50  *
  51  * \param fd The file descriptor to delete.
  52  *
  53  * Noop if \a fd does not belong to the close-on-fork list.
  54  */
  55 void del_close_on_fork_list(int fd)
  56 {
  57         struct close_on_fork *cof, *tmp;
  58
  59         if (!initialized)
  60                 return;
  61         list_for_each_entry_safe(cof, tmp, &close_on_fork_list, node) {
  62                 if (fd != cof->fd)
  63                         continue;
  64                 list_del(&cof->node);
  65                 free(cof);
  66         }
  67 }
  68
  69 /**
  70  * Close all fds in the list and destroy all list entries.
  71  *
  72  * This function calls close(3) for each fd in the close-on-fork list
  73  * and empties the list afterwards.
  74  */
  75 void close_listed_fds(void)
  76 {
  77         struct close_on_fork *cof, *tmp;
  78
  79         if (!initialized)
  80                 return;
  81         list_for_each_entry_safe(cof, tmp, &close_on_fork_list, node) {
  82                 PARA_DEBUG_LOG("closing fd %d\n", cof->fd);
  83                 close(cof->fd);
  84                 list_del(&cof->node);
  85                 free(cof);
  86         }
  87 }