/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.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.
 *
 * $FreeBSD$
 */
#ifndef _BSD_SYS_EVENT_H_
#define _BSD_SYS_EVENT_H_

#include <features.h>

#ifdef _DEFAULT_SOURCE

#include <stdint.h>


#define EVFILT_READ                     (-1)
#define EVFILT_WRITE            (-2)
#define EVFILT_PROC                     (-5)

#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
#define EV_SET(kevp_, a, b, c, d, e, f) do {    \
        *(kevp_) = (struct kevent){             \
                .ident = (a),                   \
                .filter = (b),                  \
                .flags = (c),                   \
                .fflags = (d),                  \
                .data = (e),                    \
                .udata = (f),                   \
                .ext = {0},                             \
        };                                      \
} while (0)
#else /* Pre-C99 or not STDC (e.g., C++) */
/*
 * The definition of the local variable kevp could possibly conflict
 * with a user-defined value passed in parameters a-f.
 */
#define EV_SET(kevp_, a, b, c, d, e, f) do {    \
        struct kevent *kevp = (kevp_);          \
        (kevp)->ident = (a);                    \
        (kevp)->filter = (b);                   \
        (kevp)->flags = (c);                    \
        (kevp)->fflags = (d);                   \
        (kevp)->data = (e);                     \
        (kevp)->udata = (f);                    \
        (kevp)->ext[0] = 0;                     \
        (kevp)->ext[1] = 0;                     \
        (kevp)->ext[2] = 0;                     \
        (kevp)->ext[3] = 0;                     \
} while (0)
#endif

struct kevent {
        uintptr_t       ident;          /* identifier for this event */
        short           filter;         /* filter for event */
        unsigned short  flags;          /* action flags for kqueue */
        unsigned int    fflags;         /* filter flag value */
        int64_t data;           /* filter data value */
        void            *udata;         /* opaque user data identifier */
        uint64_t        ext[4];         /* extensions */
};

/* actions */
#define EV_ADD          0x0001          /* add event to kq (implies enable) */
#define EV_DELETE       0x0002          /* delete event from kq */
#define EV_ENABLE       (0)                     /* (not needed) */

/* flags */
#define EV_ONESHOT      0x0010          /* only report one occurrence */
#define EV_CLEAR        0x0020          /* clear event state after reporting */

/* returned values */
#define EV_EOF          0x8000          /* EOF detected */
#define EV_ERROR        0x4000          /* error, data contains errno */

/* data/hint flags for EVFILT_PROC */
#define NOTE_EXIT       0x80000000              /* process exited */


#ifdef __cplusplus
extern "C" {
#endif

int     kqueue(void);
int     kevent(int kq, const struct kevent *changelist, int nchanges,
                        struct kevent *eventlist, int nevents,
                        const struct timespec *timeout);

#ifdef __cplusplus
}
#endif


#endif  /* _DEFAULT_SOURCE */

#endif  /* _BSD_SYS_EVENT_H_ */