Date: Fri, 10 Apr 1998 18:58:19 -0500 (EST) From: "John S. Dyson" <toor@dyson.iquest.net> To: alex@cs.wustl.edu (Alexander Babu Arulanthu) Cc: freebsd-questions@FreeBSD.ORG Subject: Re: aio calls in FreeBSD Message-ID: <199804102358.SAA04215@dyson.iquest.net> In-Reply-To: <352EAD31.EBD3689E@cs.wustl.edu> from Alexander Babu Arulanthu at "Apr 10, 98 06:37:21 pm"
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> Hi,
>
> Does any of the FreeBSD versions support asynchronous system calls such
> as aio_read (), aio_write () etc.
>
I am missing aio_error, but I can fix that ASAP, if you need it. It
is a work in progress (I work in a squeaky-wheel mode most of the time.)
FreeBSD-current supports the other important ones, here is the aio.h
header file:
#ifndef _AIO_H_
#define _AIO_H_
/*
* Copyright (c) 1997 John S. Dyson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. John S. Dyson's name may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* DISCLAIMER: This code isn't warranted to do anything useful. Anything
* bad that happens because of using this software isn't the responsibility
* of the author. This software is distributed AS-IS.
*
* $Id: aio.h,v 1.7 1998/03/28 11:50:34 dufault Exp $
*/
#include <sys/types.h>
#include <sys/signal.h>
/*
* Returned by aio_cancel:
* (Note that FreeBSD's aio is not cancellable -- yet.)
*/
#define AIO_CANCELED 0x1
#define AIO_NOTCANCELED 0x2
#define AIO_ALLDONE 0x3
/*
* LIO opcodes
*/
#define LIO_NOP 0x0
#define LIO_WRITE 0x1
#define LIO_READ 0x2
/*
* LIO modes
*/
#define LIO_NOWAIT 0x0
#define LIO_WAIT 0x1
/*
* Maximum number of allowed LIO operations
*/
#define AIO_LISTIO_MAX 16
/*
* Private mode bit for aio.
* (This bit is set by the library routine
* to allow the kernel to support sync
* or async operations in the future.)
*/
#define AIO_PMODE_SYNC 0x1
#define AIO_PMODE_DONE 0x2
#define AIO_PMODE_SUSPEND 0x4
#define AIO_PMODE_ACTIVE 0x2357c0de
/*
* Private members for aiocb -- don't access
* directly.
*/
struct __aiocb_private {
int status;
int error;
int privatemodes;
int active;
int tid;
int threadinfo;
void *userinfo;
void *kernelinfo;
};
/*
* I/O control block
*/
typedef struct aiocb {
int aio_fildes; /* File descriptor */
off_t aio_offset; /* File offset for I/O */
volatile void *aio_buf; /* I/O buffer in process space */
size_t aio_nbytes; /* Number of bytes for I/O */
struct sigevent aio_sigevent; /* Signal to deliver */
int aio_lio_opcode; /* LIO opcode */
int aio_reqprio; /* Request priority -- ignored */
struct __aiocb_private _aiocb_private;
} aiocb_t;
#ifndef KERNEL
/*
* Asynchronously read from a file
*/
int aio_read( struct aiocb *iocb);
/*
* Asynchronously write to file
*/
int aio_write( struct aiocb *iocb);
/*
* List I/O Asynchronously/synchronously read/write to/from file
* "lio_mode" specifies whether or not the I/O is synchronous.
* "acb_list" is an array of "nacb_listent" I/O control blocks.
* when all I/Os are complete, the optional signal "sig" is sent.
*/
int lio_listio( int lio_mode, struct aiocb * const acb_list[],
int nacb_listent, struct sigevent *sig);
/*
* Get completion status
* returns EINPROGRESS until I/O is complete.
* this routine does not block.
*/
int aio_error( const struct aiocb *iocb);
/*
* Finish up I/O, releasing I/O resources and returns the value
* that would have been associated with a synchronous I/O request.
* This routine must be called once and only once for each
* I/O control block who has had I/O associated with it.
*/
ssize_t aio_return( struct aiocb *iocb);
/*
* Cancel I/O -- implemented only to return AIO_NOTCANCELLED or
* AIO_ALLDONE. No cancellation operation will occur.
*/
int aio_cancel( int fd, struct aiocb *iocb);
/*
* Suspend until all specified I/O or timeout is complete.
*/
int aio_suspend( const struct aiocb * const acb_list[], int nacb_listent,
const struct timespec *tm);
#else
void aio_proc_rundown( struct proc *p);
#endif
#endif
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