xref: /freebsd/sys/sys/aio.h (revision 0f606585b82cdc5e5f433c2706394164f7b5ec55)

#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 1.1 1997/05/22 00:19:44 toor Exp $
 */

#include <sys/types.h>

/**************************************************************************/
/* Additions to signal.h -- hack alert.                                   */
/**************************************************************************/
/*
 * sigval structure:
 */
union sigval {
	int	sival_int;
	void	*sival_ptr;
};

/*
 * this is the sigevent structure:
 */
struct sigevent {
	int	sigev_notify;		/* Notification */
	int	sigev_signo;		/* Signal number */
	union sigval sigev_value;	/* Not used yet in FreeBSD */
};

/*
 * values for sigev_notify:
 */
#define	SIGEV_NONE	0		/* Don't post a signal */
#define	SIGEV_SIGNAL	1		/* Post specified signal */

/**************************************************************************/
/* Actual AIO header                                                      */
/**************************************************************************/
/*
 * Returned by aio_cancel:
 *  (Note that FreeBSD's aio is not cancellable -- yet.)
 */
#define	AIO_CANCELED		0x1
#define AIO_NOTCANCELLED	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

/*
 * I/O active flag -- used for compat
 * with kernel.
 */
#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 */
	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( 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.
 */
int 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( struct aiocb * const acb_list[], int nacb_listent,
		 struct timespec *tm);

#endif
#endif