resolv/gai_misc.h

   1 /* Copyright (C) 2001-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _GAI_MISC_H
  20 #define _GAI_MISC_H     1
  21
  22 #include <netdb.h>
  23 #include <signal.h>
  24
  25
  26 /* Used to synchronize.  */
  27 struct waitlist
  28   {
  29     struct waitlist *next;
  30
  31 #ifndef DONT_NEED_GAI_MISC_COND
  32     pthread_cond_t *cond;
  33 #endif
  34     volatile unsigned int *counterp;
  35     /* The next field is used in asynchronous `lio_listio' operations.  */
  36     struct sigevent *sigevp;
  37     /* XXX See requestlist, it's used to work around the broken signal
  38        handling in Linux.  */
  39     pid_t caller_pid;
  40   };
  41
  42
  43 /* Used to queue requests..  */
  44 struct requestlist
  45   {
  46     int running;
  47
  48     struct requestlist *next;
  49
  50     /* Pointer to the actual data.  */
  51     struct gaicb *gaicbp;
  52
  53     /* List of waiting processes.  */
  54     struct waitlist *waiting;
  55   };
  56
  57 /* To customize the implementation one can use the following struct.
  58    This implementation follows the one in Irix.  */
  59 struct gaiinit
  60   {
  61     int gai_threads;            /* Maximal number of threads.  */
  62     int gai_num;                /* Number of expected simultanious requests. */
  63     int gai_locks;              /* Not used.  */
  64     int gai_usedba;             /* Not used.  */
  65     int gai_debug;              /* Not used.  */
  66     int gai_numusers;           /* Not used.  */
  67     int gai_idle_time;          /* Number of seconds before idle thread
  68                                    terminates.  */
  69     int gai_reserved;
  70   };
  71
  72
  73 /* Lock for global I/O list of requests.  */
  74 extern pthread_mutex_t __gai_requests_mutex;
  75
  76
  77 /* Enqueue request.  */
  78 extern struct requestlist *__gai_enqueue_request (struct gaicb *gaicbp)
  79      attribute_hidden;
  80
  81 /* Find request on wait list.  */
  82 extern struct requestlist *__gai_find_request (const struct gaicb *gaicbp)
  83      attribute_hidden;
  84
  85 /* Remove request from waitlist.  */
  86 extern int __gai_remove_request (struct gaicb *gaicbp)
  87      attribute_hidden;
  88
  89 /* Notify initiator of request and tell this everybody listening.  */
  90 extern void __gai_notify (struct requestlist *req)
  91      attribute_hidden;
  92
  93 /* Notify initiator of request.  */
  94 extern int __gai_notify_only (struct sigevent *sigev, pid_t caller_pid)
  95      attribute_hidden;
  96
  97 /* Send the signal.  */
  98 extern int __gai_sigqueue (int sig, const union sigval val, pid_t caller_pid);
  99
 100 #endif /* gai_misc.h */