LCOM1920-T02G10

/*        $NetBSD: aio.h,v 1.12 2012/01/07 19:48:19 christos Exp $        */

/*

 * Copyright (c) 2007, Mindaugas Rasiukevicius <rmind at NetBSD org>

 * 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. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

#ifndef _SYS_AIO_H_

#define _SYS_AIO_H_

#include <sys/types.h>

#include <sys/signal.h>

/* Returned by aio_cancel() */

#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

/*

 * Asynchronous I/O structure.

 * Defined in the Base Definitions volume of IEEE Std 1003.1-2001 .

 */

struct aiocb {

        off_t aio_offset;                /* File offset */

        volatile void *aio_buf;                /* I/O buffer in process space */

        size_t aio_nbytes;                /* Length of transfer */

        int aio_fildes;                        /* File descriptor */

        int aio_lio_opcode;                /* LIO opcode */

        int aio_reqprio;                /* Request priority offset */

        struct sigevent aio_sigevent;        /* Signal to deliver */

        /* Internal kernel variables */

        int _state;                        /* State of the job */

        int _errno;                        /* Error value */

        ssize_t _retval;                /* Return value */

};

/* Internal kernel data */

#ifdef _KERNEL

/* Default limits of allowed AIO operations */

#define AIO_LISTIO_MAX                512

#define AIO_MAX                        AIO_LISTIO_MAX * 16

#include <sys/condvar.h>

#include <sys/lwp.h>

#include <sys/mutex.h>

#include <sys/pool.h>

#include <sys/queue.h>

/* Operations (as flags) */

#define AIO_LIO                        0x00

#define AIO_READ                0x01

#define AIO_WRITE                0x02

#define AIO_SYNC                0x04

#define AIO_DSYNC                0x08

/* Job states */

#define JOB_NONE                0x0

#define JOB_WIP                        0x1

#define JOB_DONE                0x2

/* Structure of AIO job */

struct aio_job {

        int aio_op;                /* Operation code */

        struct aiocb aiocbp;        /* AIO data structure */

        void *aiocb_uptr;        /* User-space pointer for identification of job */

        TAILQ_ENTRY(aio_job) list;

        struct lio_req *lio;

};

/* LIO structure */

struct lio_req {

        u_int refcnt;                /* Reference counter */

        struct sigevent sig;        /* Signal of lio_listio() calls */

};

/* Structure of AIO data for process */

struct aioproc {

        kmutex_t aio_mtx;                /* Protects the entire structure */

        kcondvar_t aio_worker_cv;        /* Signals on a new job */

        kcondvar_t done_cv;                /* Signals when the job is done */

        struct aio_job *curjob;                /* Currently processing AIO job */

        unsigned int jobs_count;        /* Count of the jobs */

        TAILQ_HEAD(, aio_job) jobs_queue;/* Queue of the AIO jobs */

        struct lwp *aio_worker;                /* AIO worker thread */

};

extern u_int aio_listio_max;

/* Prototypes */

void        aio_print_jobs(void (*)(const char *, ...) __printflike(1, 2));

int        aio_suspend1(struct lwp *, struct aiocb **, int, struct timespec *);

#endif /* _KERNEL */

#endif /* _SYS_AIO_H_ */