resolv/gai_misc.h

   1 /* Copyright (C) 2001-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _GAI_MISC_H
  19 #define _GAI_MISC_H     1
  20
  21 #include <netdb.h>
  22 #include <signal.h>
  23
  24
  25 /* Used to synchronize.  */
  26 struct waitlist
  27   {
  28     struct waitlist *next;
  29
  30 #ifndef DONT_NEED_GAI_MISC_COND
  31     pthread_cond_t *cond;
  32 #endif
  33     volatile unsigned int *counterp;
  34     /* The next field is used in asynchronous `lio_listio' operations.  */
  35     struct sigevent *sigevp;
  36     /* XXX See requestlist, it's used to work around the broken signal
  37        handling in Linux.  */
  38     pid_t caller_pid;
  39   };
  40
  41
  42 /* Used to queue requests..  */
  43 struct requestlist
  44   {
  45     int running;
  46
  47     struct requestlist *next;
  48
  49     /* Pointer to the actual data.  */
  50     struct gaicb *gaicbp;
  51
  52     /* List of waiting processes.  */
  53     struct waitlist *waiting;
  54   };
  55
  56 /* To customize the implementation one can use the following struct.
  57    This implementation follows the one in Irix.  */
  58 struct gaiinit
  59   {
  60     int gai_threads;            /* Maximal number of threads.  */
  61     int gai_num;                /* Number of expected simultanious requests. */
  62     int gai_locks;              /* Not used.  */
  63     int gai_usedba;             /* Not used.  */
  64     int gai_debug;              /* Not used.  */
  65     int gai_numusers;           /* Not used.  */
  66     int gai_idle_time;          /* Number of seconds before idle thread
  67                                    terminates.  */
  68     int gai_reserved;
  69   };
  70
  71
  72 /* Lock for global I/O list of requests.  */
  73 extern pthread_mutex_t __gai_requests_mutex;
  74
  75
  76 /* Enqueue request.  */
  77 extern struct requestlist *__gai_enqueue_request (struct gaicb *gaicbp)
  78      attribute_hidden;
  79
  80 /* Find request on wait list.  */
  81 extern struct requestlist *__gai_find_request (const struct gaicb *gaicbp)
  82      attribute_hidden;
  83
  84 /* Remove request from waitlist.  */
  85 extern int __gai_remove_request (struct gaicb *gaicbp)
  86      attribute_hidden;
  87
  88 /* Notify initiator of request and tell this everybody listening.  */
  89 extern void __gai_notify (struct requestlist *req)
  90      attribute_hidden;
  91
  92 /* Notify initiator of request.  */
  93 extern int __gai_notify_only (struct sigevent *sigev, pid_t caller_pid)
  94      attribute_hidden;
  95
  96 /* Send the signal.  */
  97 extern int __gai_sigqueue (int sig, const union sigval val, pid_t caller_pid);
  98 libc_hidden_proto (__gai_sigqueue)
  99
 100 #endif /* gai_misc.h */