sysdeps/generic/aio_misc.h

   1 /* Copyright (C) 1997-2023 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 _AIO_MISC_H
  19 #define _AIO_MISC_H     1
  20
  21 #include <aio.h>
  22 #include <pthread.h>
  23
  24
  25 /* Extend the operation enum.  */
  26 enum
  27 {
  28   LIO_DSYNC = LIO_NOP + 1,
  29   LIO_SYNC,
  30   LIO_READ64 = LIO_READ | 128,
  31   LIO_WRITE64 = LIO_WRITE | 128
  32 };
  33
  34
  35 /* Union of the two request types.  */
  36 typedef union
  37   {
  38     struct aiocb aiocb;
  39     struct aiocb64 aiocb64;
  40   } aiocb_union;
  41
  42
  43 /* Used to synchronize.  */
  44 struct waitlist
  45   {
  46     struct waitlist *next;
  47
  48     /* The next two fields is used in synchronous `lio_listio' operations.  */
  49 #ifndef DONT_NEED_AIO_MISC_COND
  50     pthread_cond_t *cond;
  51 #endif
  52     int *result;
  53
  54     volatile unsigned int *counterp;
  55     /* The next field is used in asynchronous `lio_listio' operations.  */
  56     struct sigevent *sigevp;
  57   };
  58
  59
  60 /* Status of a request.  */
  61 enum
  62 {
  63   no,
  64   queued,
  65   yes,
  66   allocated,
  67   done
  68 };
  69
  70
  71 /* Used to queue requests..  */
  72 struct requestlist
  73   {
  74     int running;
  75
  76     struct requestlist *last_fd;
  77     struct requestlist *next_fd;
  78     struct requestlist *next_prio;
  79     struct requestlist *next_run;
  80
  81     /* Pointer to the actual data.  */
  82     aiocb_union *aiocbp;
  83
  84     /* List of waiting processes.  */
  85     struct waitlist *waiting;
  86   };
  87
  88
  89 /* Lock for global I/O list of requests.  */
  90 extern pthread_mutex_t __aio_requests_mutex attribute_hidden;
  91
  92
  93 /* Enqueue request.  */
  94 extern struct requestlist *__aio_enqueue_request (aiocb_union *aiocbp,
  95                                                   int operation)
  96   attribute_hidden;
  97
  98 /* Find request entry for given AIO control block.  */
  99 extern struct requestlist *__aio_find_req (aiocb_union *elem) attribute_hidden;
 100
 101 /* Find request entry for given file descriptor.  */
 102 extern struct requestlist *__aio_find_req_fd (int fildes) attribute_hidden;
 103
 104 /* Remove request from the list.  */
 105 extern void __aio_remove_request (struct requestlist *last,
 106                                   struct requestlist *req, int all)
 107   attribute_hidden;
 108
 109 /* Release the entry for the request.  */
 110 extern void __aio_free_request (struct requestlist *req) attribute_hidden;
 111
 112 /* Notify initiator of request and tell this everybody listening.  */
 113 extern void __aio_notify (struct requestlist *req) attribute_hidden;
 114
 115 /* Notify initiator of request.  */
 116 extern int __aio_notify_only (struct sigevent *sigev) attribute_hidden;
 117
 118 /* Send the signal.  */
 119 extern int __aio_sigqueue (int sig, const union sigval val, pid_t caller_pid)
 120   attribute_hidden;
 121
 122 #endif /* aio_misc.h */