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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 
     22 /*
     23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
     28 /* All Rights Reserved */
     29 
     30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     31 
     32 #include "lint.h"
     33 #include "mtlib.h"
     34 #include "file64.h"
     35 #include <stdio.h>
     36 #include <thread.h>
     37 #include <synch.h>
     38 #include <stdlib.h>
     39 #include <errno.h>
     40 #include <stdio_ext.h>
     41 #include "stdiom.h"
     42 
     43 #define	_iob	__iob
     44 
     45 /*
     46  * _flockget and _flockrel are only called by the
     47  * FLOCKFILE/FUNLOCKFILE macros in mtlib.h.
     48  */
     49 
     50 /*
     51  * compute the lock's position, acquire it and return its pointer
     52  */
     53 
     54 rmutex_t *
     55 _flockget(FILE *iop)
     56 {
     57 	rmutex_t *rl = IOB_LCK(iop);
     58 
     59 	if (rl != NULL)
     60 		cancel_safe_mutex_lock(rl);
     61 	return (rl);
     62 }
     63 
     64 int
     65 ftrylockfile(FILE *iop)
     66 {
     67 	rmutex_t *rl = IOB_LCK(iop);
     68 
     69 	if (rl != NULL)
     70 		return (mutex_trylock(rl));
     71 	return (0);	/* can't happen? */
     72 }
     73 
     74 void
     75 flockfile(FILE *iop)
     76 {
     77 	rmutex_t *rl = IOB_LCK(iop);
     78 
     79 	if (rl != NULL)
     80 		(void) mutex_lock(rl);
     81 }
     82 
     83 void
     84 funlockfile(FILE *iop)
     85 {
     86 	rmutex_t *rl = IOB_LCK(iop);
     87 
     88 	if (rl != NULL)
     89 		(void) mutex_unlock(rl);
     90 }
     91 
     92 int
     93 __fsetlocking(FILE *iop, int type)
     94 {
     95 	int	ret = 0;
     96 
     97 	ret = GET_IONOLOCK(iop) ? FSETLOCKING_BYCALLER : FSETLOCKING_INTERNAL;
     98 
     99 	switch (type) {
    100 
    101 	case FSETLOCKING_QUERY:
    102 		break;
    103 
    104 	case FSETLOCKING_INTERNAL:
    105 		CLEAR_IONOLOCK(iop);
    106 		break;
    107 
    108 	case FSETLOCKING_BYCALLER:
    109 		SET_IONOLOCK(iop);
    110 		break;
    111 
    112 	default:
    113 		errno = EINVAL;
    114 		return (-1);
    115 	}
    116 
    117 	return (ret);
    118 }
    119