bsd/sys/aio.h

   1 /*
   2  * Copyright (c) 2003-2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  *      File:   sys/aio.h
  30  *      Author: Umesh Vaishampayan [umeshv@apple.com]
  31  *                      05-Feb-2003     umeshv  Created.
  32  *
  33  *      Header file for POSIX Asynchronous IO APIs
  34  *
  35  */
  36
  37 #ifndef _SYS_AIO_H_
  38 #define _SYS_AIO_H_
  39
  40 #include <sys/signal.h>
  41 #include <sys/_types.h>
  42 #include <sys/cdefs.h>
  43
  44 /*
  45  * [XSI] Inclusion of the <aio.h> header may make visible symbols defined
  46  * in the headers <fcntl.h>, <signal.h>, <sys/types.h>, and <time.h>.
  47  *
  48  * In our case, this is limited to struct timespec, off_t and ssize_t.
  49  */
  50 #include <sys/_types/_timespec.h>
  51 #ifdef KERNEL
  52 #include <sys/_types/_user64_timespec.h>
  53 #include <sys/_types/_user32_timespec.h>
  54 #endif /* KERNEL */
  55
  56 #include <sys/_types/_off_t.h>
  57 #include <sys/_types/_ssize_t.h>
  58
  59 /*
  60  * A aio_fsync() options that the calling thread is to continue execution
  61  * while the lio_listio() operation is being performed, and no notification
  62  * is given when the operation is complete
  63  *
  64  * [XSI] from <fcntl.h>
  65  */
  66 #include <sys/_types/_o_sync.h>
  67 #include <sys/_types/_o_dsync.h>
  68
  69 #ifndef KERNEL
  70 struct aiocb {
  71         int             aio_fildes;             /* File descriptor */
  72         off_t           aio_offset;             /* File offset */
  73         volatile void   *aio_buf;               /* Location of buffer */
  74         size_t          aio_nbytes;             /* Length of transfer */
  75         int             aio_reqprio;            /* Request priority offset */
  76         struct sigevent aio_sigevent;           /* Signal number and value */
  77         int             aio_lio_opcode;         /* Operation to be performed */
  78 };
  79 #endif /* KERNEL */
  80
  81 #ifdef KERNEL
  82
  83 struct user_aiocb {
  84         int             aio_fildes;             /* File descriptor */
  85         off_t           aio_offset; /* File offset */
  86         user_addr_t     aio_buf;                /* Location of buffer */
  87         user_size_t     aio_nbytes;             /* Length of transfer */
  88         int             aio_reqprio;    /* Request priority offset */
  89         struct user_sigevent aio_sigevent;      /* Signal number and value */
  90         int             aio_lio_opcode;         /* Operation to be performed */
  91 };
  92
  93 struct user64_aiocb {
  94         int             aio_fildes;             /* File descriptor */
  95         user64_off_t            aio_offset; /* File offset */
  96         user64_addr_t   aio_buf;                /* Location of buffer */
  97         user64_size_t   aio_nbytes;             /* Length of transfer */
  98         int             aio_reqprio;    /* Request priority offset */
  99         struct user64_sigevent aio_sigevent;    /* Signal number and value */
 100         int             aio_lio_opcode;         /* Operation to be performed */
 101 };
 102
 103 struct user32_aiocb {
 104         int             aio_fildes;             /* File descriptor */
 105         user32_off_t            aio_offset;             /* File offset */
 106         user32_addr_t   aio_buf;                /* Location of buffer */
 107         user32_size_t   aio_nbytes;             /* Length of transfer */
 108         int             aio_reqprio;            /* Request priority offset */
 109         struct user32_sigevent  aio_sigevent;           /* Signal number and value */
 110         int             aio_lio_opcode;         /* Operation to be performed */
 111 };
 112
 113 #endif // KERNEL
 114
 115 /*
 116  * aio_cancel() return values
 117  */
 118
 119 /*
 120  * none of the requested operations could be canceled since they are
 121  * already complete.
 122  */
 123 #define AIO_ALLDONE                     0x1
 124
 125 /* all requested operations have been canceled */
 126 #define AIO_CANCELED            0x2
 127
 128 /*
 129  * some of the requested operations could not be canceled since
 130  * they are in progress
 131  */
 132 #define AIO_NOTCANCELED         0x4
 133
 134
 135 /*
 136  * lio_listio operation options
 137  */
 138
 139 #define LIO_NOP                 0x0     /* option indicating that no transfer is requested */
 140 #define LIO_READ                0x1             /* option requesting a read */
 141 #define LIO_WRITE               0x2             /* option requesting a write */
 142
 143 /*
 144  * lio_listio() modes
 145  */
 146
 147 /*
 148  * A lio_listio() synchronization operation indicating
 149  * that the calling thread is to continue execution while
 150  * the lio_listio() operation is being performed, and no
 151  * notification is given when the operation is complete
 152  */
 153 #define LIO_NOWAIT              0x1
 154
 155 /*
 156  * A lio_listio() synchronization operation indicating
 157  * that the calling thread is to suspend until the
 158  * lio_listio() operation is complete.
 159  */
 160 #define LIO_WAIT                0x2
 161
 162 /*
 163  * Maximum number of operations in single lio_listio call
 164  */
 165 #define AIO_LISTIO_MAX          16
 166
 167
 168 #ifndef KERNEL
 169 /*
 170  * Prototypes
 171  */
 172
 173 __BEGIN_DECLS
 174
 175 /*
 176  * Attempt to cancel one or more asynchronous I/O requests currently outstanding
 177  * against file descriptor fd. The aiocbp argument points to the asynchronous I/O
 178  * control block for a particular request to be canceled.  If aiocbp is NULL, then
 179  * all outstanding cancelable asynchronous I/O requests against fd shall be canceled.
 180  */
 181 int             aio_cancel( int fd,
 182     struct aiocb * aiocbp );
 183
 184 /*
 185  * Return the error status associated with the aiocb structure referenced by the
 186  * aiocbp argument. The error status for an asynchronous I/O operation is the errno
 187  * value that would be set by the corresponding read(), write(),  or fsync()
 188  * operation.  If the operation has not yet completed, then the error status shall
 189  * be equal to [EINPROGRESS].
 190  */
 191 int             aio_error( const struct aiocb * aiocbp );
 192
 193 /*
 194  * Asynchronously force all I/O operations associated with the file indicated by
 195  * the file descriptor aio_fildes member of the aiocb structure referenced by the
 196  * aiocbp argument and queued at the time of the call to aio_fsync() to the
 197  * synchronized I/O completion state.  The function call shall return when the
 198  * synchronization request has been initiated or queued.  op O_SYNC is the only
 199  * supported opertation at this time.
 200  * The aiocbp argument refers to an asynchronous I/O control block. The aiocbp
 201  * value may be used as an argument to aio_error() and aio_return() in order to
 202  * determine the error status and return status, respectively, of the asynchronous
 203  * operation while it is proceeding.  When the request is queued, the error status
 204  * for the operation is [EINPROGRESS]. When all data has been successfully
 205  * transferred, the error status shall be reset to reflect the success or failure
 206  * of the operation.
 207  */
 208 int             aio_fsync( int op,
 209     struct aiocb * aiocbp );
 210
 211 /*
 212  * Read aiocbp->aio_nbytes from the file associated with aiocbp->aio_fildes into
 213  * the buffer pointed to by aiocbp->aio_buf.  The function call shall return when
 214  * the read request has been initiated or queued.
 215  * The aiocbp value may be used as an argument to aio_error() and aio_return() in
 216  * order to determine the error status and return status, respectively, of the
 217  * asynchronous operation while it is proceeding. If an error condition is
 218  * encountered during queuing, the function call shall return without having
 219  * initiated or queued the request. The requested operation takes place at the
 220  * absolute position in the file as given by aio_offset, as if lseek() were called
 221  * immediately prior to the operation with an offset equal to aio_offset and a
 222  * whence equal to SEEK_SET.  After a successful call to enqueue an asynchronous
 223  * I/O operation, the value of the file offset for the file is unspecified.
 224  */
 225 int             aio_read( struct aiocb * aiocbp );
 226
 227 /*
 228  * Return the return status associated with the aiocb structure referenced by
 229  * the aiocbp argument.  The return status for an asynchronous I/O operation is
 230  * the value that would be returned by the corresponding read(), write(), or
 231  * fsync() function call.  If the error status for the operation is equal to
 232  * [EINPROGRESS], then the return status for the operation is undefined.  The
 233  * aio_return() function may be called exactly once to retrieve the return status
 234  * of a given asynchronous operation; thereafter, if the same aiocb structure
 235  * is used in a call to aio_return() or aio_error(), an error may be returned.
 236  * When the aiocb structure referred to by aiocbp is used to submit another
 237  * asynchronous operation, then aio_return() may be successfully used to
 238  * retrieve the return status of that operation.
 239  */
 240 ssize_t aio_return( struct aiocb * aiocbp );
 241
 242 /*
 243  * Suspend the calling thread until at least one of the asynchronous I/O
 244  * operations referenced by the aiocblist argument has completed, until a signal
 245  * interrupts the function, or, if timeout is not NULL, until the time
 246  * interval specified by timeout has passed.  If any of the aiocb structures
 247  * in the aiocblist correspond to completed asynchronous I/O operations (that is,
 248  * the error status for the operation is not equal to [EINPROGRESS]) at the
 249  * time of the call, the function shall return without suspending the calling
 250  * thread.  The aiocblist argument is an array of pointers to asynchronous I/O
 251  * control blocks.  The nent argument indicates the number of elements in the
 252  * array.  Each aiocb structure pointed to has been used in initiating an
 253  * asynchronous I/O request via aio_read(), aio_write(), or lio_listio(). This
 254  * array may contain NULL pointers, which are ignored.
 255  */
 256 int             aio_suspend( const struct aiocb *const aiocblist[],
 257     int nent,
 258     const struct timespec * timeoutp ) __DARWIN_ALIAS_C(aio_suspend);
 259
 260 /*
 261  * Write aiocbp->aio_nbytes to the file associated with aiocbp->aio_fildes from
 262  * the buffer pointed to by aiocbp->aio_buf.  The function shall return when the
 263  * write request has been initiated or, at a minimum, queued.
 264  * The aiocbp argument may be used as an argument to aio_error() and aio_return()
 265  * in order to determine the error status and return status, respectively, of the
 266  * asynchronous operation while it is proceeding.
 267  */
 268 int             aio_write( struct aiocb * aiocbp );
 269
 270 /*
 271  * Initiate a list of I/O requests with a single function call.  The mode
 272  * argument takes one of the values LIO_WAIT or LIO_NOWAIT and determines whether
 273  * the function returns when the I/O operations have been completed, or as soon
 274  * as the operations have been queued.  If the mode argument is LIO_WAIT, the
 275  * function shall wait until all I/O is complete and the sig argument shall be
 276  * ignored.
 277  * If the mode argument is LIO_NOWAIT, the function shall return immediately, and
 278  * asynchronous notification shall occur, according to the sig argument, when all
 279  * the I/O operations complete.  If sig is NULL, then no asynchronous notification
 280  * shall occur.
 281  */
 282 int             lio_listio( int mode,
 283     struct aiocb *const aiocblist[],
 284     int nent,
 285     struct sigevent *sigp );
 286 __END_DECLS
 287
 288 #endif /* KERNEL */
 289 #endif /* _SYS_AIO_H_ */