rt/aio.h

   1 /* Copyright (C) 1996-2019 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 /*
  19  * ISO/IEC 9945-1:1996 6.7: Asynchronous Input and Output
  20  */
  21
  22 #ifndef _AIO_H
  23 #define _AIO_H  1
  24
  25 #include <features.h>
  26 #include <sys/types.h>
  27 #include <bits/types/sigevent_t.h>
  28 #include <bits/sigevent-consts.h>
  29 #include <bits/types/struct_timespec.h>
  30
  31 __BEGIN_DECLS
  32
  33 /* Asynchronous I/O control block.  */
  34 struct aiocb
  35 {
  36   int aio_fildes;               /* File desriptor.  */
  37   int aio_lio_opcode;           /* Operation to be performed.  */
  38   int aio_reqprio;              /* Request priority offset.  */
  39   volatile void *aio_buf;       /* Location of buffer.  */
  40   size_t aio_nbytes;            /* Length of transfer.  */
  41   struct sigevent aio_sigevent; /* Signal number and value.  */
  42
  43   /* Internal members.  */
  44   struct aiocb *__next_prio;
  45   int __abs_prio;
  46   int __policy;
  47   int __error_code;
  48   __ssize_t __return_value;
  49
  50 #ifndef __USE_FILE_OFFSET64
  51   __off_t aio_offset;           /* File offset.  */
  52   char __pad[sizeof (__off64_t) - sizeof (__off_t)];
  53 #else
  54   __off64_t aio_offset;         /* File offset.  */
  55 #endif
  56   char __glibc_reserved[32];
  57 };
  58
  59 /* The same for the 64bit offsets.  Please note that the members aio_fildes
  60    to __return_value have to be the same in aiocb and aiocb64.  */
  61 #ifdef __USE_LARGEFILE64
  62 struct aiocb64
  63 {
  64   int aio_fildes;               /* File desriptor.  */
  65   int aio_lio_opcode;           /* Operation to be performed.  */
  66   int aio_reqprio;              /* Request priority offset.  */
  67   volatile void *aio_buf;       /* Location of buffer.  */
  68   size_t aio_nbytes;            /* Length of transfer.  */
  69   struct sigevent aio_sigevent; /* Signal number and value.  */
  70
  71   /* Internal members.  */
  72   struct aiocb *__next_prio;
  73   int __abs_prio;
  74   int __policy;
  75   int __error_code;
  76   __ssize_t __return_value;
  77
  78   __off64_t aio_offset;         /* File offset.  */
  79   char __glibc_reserved[32];
  80 };
  81 #endif
  82
  83
  84 #ifdef __USE_GNU
  85 /* To customize the implementation one can use the following struct.
  86    This implementation follows the one in Irix.  */
  87 struct aioinit
  88   {
  89     int aio_threads;            /* Maximal number of threads.  */
  90     int aio_num;                /* Number of expected simultanious requests. */
  91     int aio_locks;              /* Not used.  */
  92     int aio_usedba;             /* Not used.  */
  93     int aio_debug;              /* Not used.  */
  94     int aio_numusers;           /* Not used.  */
  95     int aio_idle_time;          /* Number of seconds before idle thread
  96                                    terminates.  */
  97     int aio_reserved;
  98   };
  99 #endif
 100
 101
 102 /* Return values of cancelation function.  */
 103 enum
 104 {
 105   AIO_CANCELED,
 106 #define AIO_CANCELED AIO_CANCELED
 107   AIO_NOTCANCELED,
 108 #define AIO_NOTCANCELED AIO_NOTCANCELED
 109   AIO_ALLDONE
 110 #define AIO_ALLDONE AIO_ALLDONE
 111 };
 112
 113
 114 /* Operation codes for `aio_lio_opcode'.  */
 115 enum
 116 {
 117   LIO_READ,
 118 #define LIO_READ LIO_READ
 119   LIO_WRITE,
 120 #define LIO_WRITE LIO_WRITE
 121   LIO_NOP
 122 #define LIO_NOP LIO_NOP
 123 };
 124
 125
 126 /* Synchronization options for `lio_listio' function.  */
 127 enum
 128 {
 129   LIO_WAIT,
 130 #define LIO_WAIT LIO_WAIT
 131   LIO_NOWAIT
 132 #define LIO_NOWAIT LIO_NOWAIT
 133 };
 134
 135
 136 /* Allow user to specify optimization.  */
 137 #ifdef __USE_GNU
 138 extern void aio_init (const struct aioinit *__init) __THROW __nonnull ((1));
 139 #endif
 140
 141
 142 #ifndef __USE_FILE_OFFSET64
 143 /* Enqueue read request for given number of bytes and the given priority.  */
 144 extern int aio_read (struct aiocb *__aiocbp) __THROW __nonnull ((1));
 145 /* Enqueue write request for given number of bytes and the given priority.  */
 146 extern int aio_write (struct aiocb *__aiocbp) __THROW __nonnull ((1));
 147
 148 /* Initiate list of I/O requests.  */
 149 extern int lio_listio (int __mode,
 150                        struct aiocb *const __list[__restrict_arr],
 151                        int __nent, struct sigevent *__restrict __sig)
 152   __THROW __nonnull ((2));
 153
 154 /* Retrieve error status associated with AIOCBP.  */
 155 extern int aio_error (const struct aiocb *__aiocbp) __THROW __nonnull ((1));
 156 /* Return status associated with AIOCBP.  */
 157 extern __ssize_t aio_return (struct aiocb *__aiocbp) __THROW __nonnull ((1));
 158
 159 /* Try to cancel asynchronous I/O requests outstanding against file
 160    descriptor FILDES.  */
 161 extern int aio_cancel (int __fildes, struct aiocb *__aiocbp) __THROW;
 162
 163 /* Suspend calling thread until at least one of the asynchronous I/O
 164    operations referenced by LIST has completed.
 165
 166    This function is a cancellation point and therefore not marked with
 167    __THROW.  */
 168 extern int aio_suspend (const struct aiocb *const __list[], int __nent,
 169                         const struct timespec *__restrict __timeout)
 170   __nonnull ((1));
 171
 172 /* Force all operations associated with file desriptor described by
 173    `aio_fildes' member of AIOCBP.  */
 174 extern int aio_fsync (int __operation, struct aiocb *__aiocbp)
 175   __THROW __nonnull ((2));
 176 #else
 177 # ifdef __REDIRECT_NTH
 178 extern int __REDIRECT_NTH (aio_read, (struct aiocb *__aiocbp), aio_read64)
 179   __nonnull ((1));
 180 extern int __REDIRECT_NTH (aio_write, (struct aiocb *__aiocbp), aio_write64)
 181   __nonnull ((1));
 182
 183 extern int __REDIRECT_NTH (lio_listio,
 184                            (int __mode,
 185                             struct aiocb *const __list[__restrict_arr],
 186                             int __nent, struct sigevent *__restrict __sig),
 187                            lio_listio64) __nonnull ((2));
 188
 189 extern int __REDIRECT_NTH (aio_error, (const struct aiocb *__aiocbp),
 190                            aio_error64) __nonnull ((1));
 191 extern __ssize_t __REDIRECT_NTH (aio_return, (struct aiocb *__aiocbp),
 192                                  aio_return64) __nonnull ((1));
 193
 194 extern int __REDIRECT_NTH (aio_cancel,
 195                            (int __fildes, struct aiocb *__aiocbp),
 196                            aio_cancel64);
 197
 198 extern int __REDIRECT_NTH (aio_suspend,
 199                            (const struct aiocb *const __list[], int __nent,
 200                             const struct timespec *__restrict __timeout),
 201                            aio_suspend64) __nonnull ((1));
 202
 203 extern int __REDIRECT_NTH (aio_fsync,
 204                            (int __operation, struct aiocb *__aiocbp),
 205                            aio_fsync64) __nonnull ((2));
 206
 207 # else
 208 #  define aio_read aio_read64
 209 #  define aio_write aio_write64
 210 #  define lio_listio lio_listio64
 211 #  define aio_error aio_error64
 212 #  define aio_return aio_return64
 213 #  define aio_cancel aio_cancel64
 214 #  define aio_suspend aio_suspend64
 215 #  define aio_fsync aio_fsync64
 216 # endif
 217 #endif
 218
 219 #ifdef __USE_LARGEFILE64
 220 extern int aio_read64 (struct aiocb64 *__aiocbp) __THROW __nonnull ((1));
 221 extern int aio_write64 (struct aiocb64 *__aiocbp) __THROW __nonnull ((1));
 222
 223 extern int lio_listio64 (int __mode,
 224                          struct aiocb64 *const __list[__restrict_arr],
 225                          int __nent, struct sigevent *__restrict __sig)
 226   __THROW __nonnull ((2));
 227
 228 extern int aio_error64 (const struct aiocb64 *__aiocbp)
 229   __THROW __nonnull ((1));
 230 extern __ssize_t aio_return64 (struct aiocb64 *__aiocbp)
 231   __THROW __nonnull ((1));
 232
 233 extern int aio_cancel64 (int __fildes, struct aiocb64 *__aiocbp) __THROW;
 234
 235 extern int aio_suspend64 (const struct aiocb64 *const __list[], int __nent,
 236                           const struct timespec *__restrict __timeout)
 237   __THROW __nonnull ((1));
 238
 239 extern int aio_fsync64 (int __operation, struct aiocb64 *__aiocbp)
 240   __THROW __nonnull ((2));
 241 #endif
 242
 243 __END_DECLS
 244
 245 #endif /* aio.h */