FreeBSD/Linux Kernel Cross Reference
sys/sys/sema.h

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (C) 2001 Jason Evans <jasone@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(s), this list of conditions and the following disclaimer as
     *    the first lines of this file unmodified other than the possible
     *    addition of one or more copyright notices.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice(s), 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 COPYRIGHT HOLDER(S) ``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 COPYRIGHT HOLDER(S) 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 _SYS_SEMA_H_
    #define _SYS_SEMA_H_
    
    #include <sys/queue.h>
    #include <sys/_lock.h>
    #include <sys/_mutex.h>
    #include <sys/condvar.h>
    
    struct sema {
            struct mtx      sema_mtx;       /* General protection lock. */
            struct cv       sema_cv;        /* Waiters. */
            int             sema_waiters;   /* Number of waiters. */
            int             sema_value;     /* Semaphore value. */
    };
    
    #ifdef _KERNEL
    void    sema_init(struct sema *sema, int value, const char *description);
    void    sema_destroy(struct sema *sema);
    void    _sema_post(struct sema *sema, const char *file, int line);
    void    _sema_wait(struct sema *sema, const char *file, int line);
    int     _sema_timedwait(struct sema *sema, int timo, const char *file, int
        line);
    int     _sema_trywait(struct sema *sema, const char *file, int line);
    int     sema_value(struct sema *sema);
    
    #define sema_post(sema)         _sema_post((sema), LOCK_FILE, LOCK_LINE)
    #define sema_wait(sema)         _sema_wait((sema), LOCK_FILE, LOCK_LINE)
    #define sema_timedwait(sema, timo)                                      \
            _sema_timedwait((sema), (timo), LOCK_FILE, LOCK_LINE)
    #define sema_trywait(sema)      _sema_trywait((sema), LOCK_FILE, LOCK_LINE)
    
    #endif  /* _KERNEL */
    #endif  /* _SYS_SEMA_H_ */

Cache object: ef46aa9136a88130add1822ead35bc69