rt/aio.h

   1 /* Copyright (C) 1996-2000,2003,2004,2007 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 /*
  20  * ISO/IEC 9945-1:1996 6.7: Asynchronous Input and Output
  21  */
  22
  23 #ifndef _AIO_H
  24 #define _AIO_H  1
  25
  26 #include <features.h>
  27 #include <fcntl.h>
  28 #include <signal.h>
  29 #include <time.h>
  30 #include <sys/types.h>
  31
  32 __BEGIN_DECLS
  33
  34 /* Asynchronous I/O control block.  */
  35 struct aiocb
  36 {
  37   int aio_fildes;               /* File desriptor.  */
  38   int aio_lio_opcode;           /* Operation to be performed.  */
  39   int aio_reqprio;              /* Request priority offset.  */
  40   volatile void *aio_buf;       /* Location of buffer.  */
  41   size_t aio_nbytes;            /* Length of transfer.  */
  42   struct sigevent aio_sigevent; /* Signal number and value.  */
  43
  44   /* Internal members.  */
  45   struct aiocb *__next_prio;
  46   int __abs_prio;
  47   int __policy;
  48   int __error_code;
  49   __ssize_t __return_value;
  50
  51 #ifndef __USE_FILE_OFFSET64
  52   __off_t aio_offset;           /* File offset.  */
  53   char __pad[sizeof (__off64_t) - sizeof (__off_t)];
  54 #else
  55   __off64_t aio_offset;         /* File offset.  */
  56 #endif
  57   char __unused[32];
  58 };
  59
  60 /* The same for the 64bit offsets.  Please note that the members aio_fildes
  61    to __return_value have to be the same in aiocb and aiocb64.  */
  62 #ifdef __USE_LARGEFILE64
  63 struct aiocb64
  64 {
  65   int aio_fildes;               /* File desriptor.  */
  66   int aio_lio_opcode;           /* Operation to be performed.  */
  67   int aio_reqprio;              /* Request priority offset.  */
  68   volatile void *aio_buf;       /* Location of buffer.  */
  69   size_t aio_nbytes;            /* Length of transfer.  */
  70   struct sigevent aio_sigevent; /* Signal number and value.  */
  71
  72   /* Internal members.  */
  73   struct aiocb *__next_prio;
  74   int __abs_prio;
  75   int __policy;
  76   int __error_code;
  77   __ssize_t __return_value;
  78
  79   __off64_t aio_offset;         /* File offset.  */
  80   char __unused[32];
  81 };
  82 #endif
  83
  84
  85 #ifdef __USE_GNU
  86 /* To customize the implementation one can use the following struct.
  87    This implementation follows the one in Irix.  */
  88 struct aioinit
  89   {
  90     int aio_threads;            /* Maximal number of threads.  */
  91     int aio_num;                /* Number of expected simultanious requests. */
  92     int aio_locks;              /* Not used.  */
  93     int aio_usedba;             /* Not used.  */
  94     int aio_debug;              /* Not used.  */
  95     int aio_numusers;           /* Not used.  */
  96     int aio_idle_time;          /* Number of seconds before idle thread
  97                                    terminates.  */
  98     int aio_reserved;
  99   };
 100 #endif
 101
 102
 103 /* Return values of cancelation function.  */
 104 enum
 105 {
 106   AIO_CANCELED,
 107 #define AIO_CANCELED AIO_CANCELED
 108   AIO_NOTCANCELED,
 109 #define AIO_NOTCANCELED AIO_NOTCANCELED
 110   AIO_ALLDONE
 111 #define AIO_ALLDONE AIO_ALLDONE
 112 };
 113
 114
 115 /* Operation codes for `aio_lio_opcode'.  */
 116 enum
 117 {
 118   LIO_READ,
 119 #define LIO_READ LIO_READ
 120   LIO_WRITE,
 121 #define LIO_WRITE LIO_WRITE
 122   LIO_NOP
 123 #define LIO_NOP LIO_NOP
 124 };
 125
 126
 127 /* Synchronization options for `lio_listio' function.  */
 128 enum
 129 {
 130   LIO_WAIT,
 131 #define LIO_WAIT LIO_WAIT
 132   LIO_NOWAIT
 133 #define LIO_NOWAIT LIO_NOWAIT
 134 };
 135
 136
 137 /* Allow user to specify optimization.  */
 138 #ifdef __USE_GNU
 139 extern void aio_init (__const struct aioinit *__init) __THROW __nonnull ((1));
 140 #endif
 141
 142
 143 #ifndef __USE_FILE_OFFSET64
 144 /* Enqueue read request for given number of bytes and the given priority.  */
 145 extern int aio_read (struct aiocb *__aiocbp) __THROW __nonnull ((1));
 146 /* Enqueue write request for given number of bytes and the given priority.  */
 147 extern int aio_write (struct aiocb *__aiocbp) __THROW __nonnull ((1));
 148
 149 /* Initiate list of I/O requests.  */
 150 extern int lio_listio (int __mode,
 151                        struct aiocb *__const __list[__restrict_arr],
 152                        int __nent, struct sigevent *__restrict __sig)
 153   __THROW __nonnull ((2));
 154
 155 /* Retrieve error status associated with AIOCBP.  */
 156 extern int aio_error (__const struct aiocb *__aiocbp) __THROW __nonnull ((1));
 157 /* Return status associated with AIOCBP.  */
 158 extern __ssize_t aio_return (struct aiocb *__aiocbp) __THROW __nonnull ((1));
 159
 160 /* Try to cancel asynchronous I/O requests outstanding against file
 161    descriptor FILDES.  */
 162 extern int aio_cancel (int __fildes, struct aiocb *__aiocbp) __THROW;
 163
 164 /* Suspend calling thread until at least one of the asynchronous I/O
 165    operations referenced by LIST has completed.
 166
 167    This function is a cancellation point and therefore not marked with
 168    __THROW.  */
 169 extern int aio_suspend (__const struct aiocb *__const __list[], int __nent,
 170                         __const struct timespec *__restrict __timeout)
 171   __nonnull ((1));
 172
 173 /* Force all operations associated with file desriptor described by
 174    `aio_fildes' member of AIOCBP.  */
 175 extern int aio_fsync (int __operation, struct aiocb *__aiocbp)
 176   __THROW __nonnull ((2));
 177 #else
 178 # ifdef __REDIRECT_NTH
 179 extern int __REDIRECT_NTH (aio_read, (struct aiocb *__aiocbp), aio_read64)
 180   __nonnull ((1));
 181 extern int __REDIRECT_NTH (aio_write, (struct aiocb *__aiocbp), aio_write64)
 182   __nonnull ((1));
 183
 184 extern int __REDIRECT_NTH (lio_listio,
 185                            (int __mode,
 186                             struct aiocb *__const __list[__restrict_arr],
 187                             int __nent, struct sigevent *__restrict __sig),
 188                            lio_listio64) __nonnull ((2));
 189
 190 extern int __REDIRECT_NTH (aio_error, (__const struct aiocb *__aiocbp),
 191                            aio_error64) __nonnull ((1));
 192 extern __ssize_t __REDIRECT_NTH (aio_return, (struct aiocb *__aiocbp),
 193                                  aio_return64) __nonnull ((1));
 194
 195 extern int __REDIRECT_NTH (aio_cancel,
 196                            (int __fildes, struct aiocb *__aiocbp),
 197                            aio_cancel64);
 198
 199 extern int __REDIRECT_NTH (aio_suspend,
 200                            (__const struct aiocb *__const __list[], int __nent,
 201                             __const struct timespec *__restrict __timeout),
 202                            aio_suspend64) __nonnull ((1));
 203
 204 extern int __REDIRECT_NTH (aio_fsync,
 205                            (int __operation, struct aiocb *__aiocbp),
 206                            aio_fsync64) __nonnull ((2));
 207
 208 # else
 209 #  define aio_read aio_read64
 210 #  define aio_write aio_write64
 211 #  define lio_listio lio_listio64
 212 #  define aio_error aio_error64
 213 #  define aio_return aio_return64
 214 #  define aio_cancel aio_cancel64
 215 #  define aio_suspend aio_suspend64
 216 #  define aio_fsync aio_fsync64
 217 # endif
 218 #endif
 219
 220 #ifdef __USE_LARGEFILE64
 221 extern int aio_read64 (struct aiocb64 *__aiocbp) __THROW __nonnull ((1));
 222 extern int aio_write64 (struct aiocb64 *__aiocbp) __THROW __nonnull ((1));
 223
 224 extern int lio_listio64 (int __mode,
 225                          struct aiocb64 *__const __list[__restrict_arr],
 226                          int __nent, struct sigevent *__restrict __sig)
 227   __THROW __nonnull ((2));
 228
 229 extern int aio_error64 (__const struct aiocb64 *__aiocbp)
 230   __THROW __nonnull ((1));
 231 extern __ssize_t aio_return64 (struct aiocb64 *__aiocbp)
 232   __THROW __nonnull ((1));
 233
 234 extern int aio_cancel64 (int __fildes, struct aiocb64 *__aiocbp) __THROW;
 235
 236 extern int aio_suspend64 (__const struct aiocb64 *__const __list[], int __nent,
 237                           __const struct timespec *__restrict __timeout)
 238   __THROW __nonnull ((1));
 239
 240 extern int aio_fsync64 (int __operation, struct aiocb64 *__aiocbp)
 241   __THROW __nonnull ((2));
 242 #endif
 243
 244 __END_DECLS
 245
 246 #endif /* aio.h */