resolv/gai_misc.h

   1 /* Copyright (C) 2001 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _GAI_MISC_H
  21 #define _GAI_MISC_H     1
  22
  23 #include <netdb.h>
  24 #include <signal.h>
  25
  26
  27 /* Used to synchronize.  */
  28 struct waitlist
  29   {
  30     struct waitlist *next;
  31
  32     pthread_cond_t *cond;
  33     volatile 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      internal_function;
  79
  80 /* Find request on wait list.  */
  81 extern struct requestlist *__gai_find_request (const struct gaicb *gaicbp)
  82      internal_function;
  83
  84 /* Remove request from waitlist.  */
  85 extern int __gai_remove_request (struct gaicb *gaicbp)
  86      internal_function;
  87
  88 /* Notify initiator of request and tell this everybody listening.  */
  89 extern void __gai_notify (struct requestlist *req)
  90      internal_function;
  91
  92 /* Notify initiator of request.  */
  93 extern int __gai_notify_only (struct sigevent *sigev, pid_t caller_pid)
  94      internal_function;
  95
  96 /* Send the signal.  */
  97 extern int __gai_sigqueue (int sig, const union sigval val, pid_t caller_pid)
  98      internal_function;
  99
 100 #endif /* gai_misc.h */