/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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_SELINFO_H_
#define _SYS_SELINFO_H_

#include <sys/event.h>          /* for struct klist */

struct selfd;
TAILQ_HEAD(selfdlist, selfd);

/*
 * Used to maintain information about processes that wish to be
 * notified when I/O becomes possible.
 */
struct selinfo {
        struct selfdlist        si_tdlist;      /* List of sleeping threads. */
        struct knlist           si_note;        /* kernel note list */
        struct mtx              *si_mtx;        /* Lock for tdlist. */
};

#define SEL_WAITING(si)         (!TAILQ_EMPTY(&(si)->si_tdlist))

#ifdef _KERNEL
void    seldrain(struct selinfo *sip);
void    selrecord(struct thread *selector, struct selinfo *sip);
void    selwakeup(struct selinfo *sip);
void    selwakeuppri(struct selinfo *sip, int pri);
void    seltdfini(struct thread *td);
#endif

#endif /* !_SYS_SELINFO_H_ */