/*      $NetBSD: ksem.h,v 1.17 2023/07/11 11:37:29 riastradh Exp $      */

/*
 * Copyright (c) 2002 Alfred Perlstein <alfred@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.
 */

#ifndef _SYS_KSEM_H_
#define _SYS_KSEM_H_

#include <sys/cdefs.h>

#include <sys/types.h>

struct timespec;

#ifdef _KERNEL

#include <sys/condvar.h>
#include <sys/mutex.h>
#include <sys/queue.h>

#ifndef _KMEMUSER               /* XXX hack for fstat(8) */
#include <sys/systm.h>
#endif

struct lwp;
struct proc;

#define KSEM_MAX        128

typedef struct ksem {
        LIST_ENTRY(ksem)        ks_entry;       /* global list entry */
        struct proc *           ks_pshared_proc;/* owner of pshared sem */
        intptr_t                ks_pshared_id;  /* global id for pshared sem */
        kmutex_t                ks_lock;        /* lock on this ksem */
        kcondvar_t              ks_cv;          /* condition variable */
        u_int                   ks_pshared_fd;  /* fd in owning proc */
        u_int                   ks_ref;         /* number of references */
        u_int                   ks_value;       /* current value */
        u_int                   ks_waiters;     /* number of waiters */
        char *                  ks_name;        /* name, if named */
        size_t                  ks_namelen;     /* length of name */
        int                     ks_flags;       /* for KS_UNLINKED */
        mode_t                  ks_mode;        /* protection bits */
        uid_t                   ks_uid;         /* creator uid */
        gid_t                   ks_gid;         /* creator gid */
} ksem_t;

int do_ksem_init(struct lwp *, unsigned int, intptr_t *, copyin_t, copyout_t);
int do_ksem_open(struct lwp *, const char *, int, mode_t, unsigned int,
    intptr_t *, copyout_t);
int do_ksem_wait(struct lwp *, intptr_t, bool, struct timespec *);

extern int      ksem_max;
#endif /* _KERNEL */

#if defined(_KERNEL) || defined(_LIBC)
#define KSEM_PSHARED            0x50535244U     /* 'PSRD' */

#define KSEM_MARKER_MASK        0xff000001U
#define KSEM_MARKER_MIN         0x01000001U
#define KSEM_PSHARED_MARKER     0x70000001U     /* 'p' << 24 | 1 */
#endif /* _KERNEL || _LIBC */

#ifdef _LIBC
__BEGIN_DECLS
int _ksem_close(intptr_t);
int _ksem_destroy(intptr_t);
int _ksem_getvalue(intptr_t, int *);
int _ksem_init(unsigned int, intptr_t *);
int _ksem_open(const char *, int, mode_t, unsigned int, intptr_t *);
int _ksem_post(intptr_t);
int _ksem_timedwait(intptr_t, const struct timespec * __restrict);
int _ksem_trywait(intptr_t);
int _ksem_unlink(const char *);
int _ksem_wait(intptr_t);
__END_DECLS
#endif /* _LIBC */

#endif /* _SYS_KSEM_H_ */