1 /* $NetBSD: fflush.c,v 1.13 1999/09/20 04:39:26 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)fflush.c 8.1 (Berkeley) 6/4/93"; 43 #else 44 __RCSID("$NetBSD: fflush.c,v 1.13 1999/09/20 04:39:26 lukem Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include <assert.h> 49 #include <errno.h> 50 #include <stdio.h> 51 #include "local.h" 52 #include "reentrant.h" 53 54 #ifdef _REENT 55 extern rwlock_t __sfp_lock; 56 #endif 57 58 /* Flush a single file, or (if fp is NULL) all files. */ 59 int 60 fflush(fp) 61 FILE *fp; 62 { 63 int r; 64 65 if (fp == NULL) { 66 rwlock_rdlock(&__sfp_lock); 67 r = _fwalk(__sflush); 68 rwlock_unlock(&__sfp_lock); 69 return r; 70 } 71 72 FLOCKFILE(fp); 73 if ((fp->_flags & (__SWR | __SRW)) == 0) { 74 errno = EBADF; 75 r = EOF; 76 } else { 77 r = __sflush(fp); 78 } 79 FUNLOCKFILE(fp); 80 return r; 81 } 82 83 int 84 __sflush(fp) 85 FILE *fp; 86 { 87 unsigned char *p; 88 int n, t; 89 90 _DIAGASSERT(fp != NULL); 91 92 t = fp->_flags; 93 if ((t & __SWR) == 0) 94 return (0); 95 96 if ((p = fp->_bf._base) == NULL) 97 return (0); 98 99 n = fp->_p - p; /* write this much */ 100 101 /* 102 * Set these immediately to avoid problems with longjmp and to allow 103 * exchange buffering (via setvbuf) in user write function. 104 */ 105 fp->_p = p; 106 fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size; 107 108 for (; n > 0; n -= t, p += t) { 109 t = (*fp->_write)(fp->_cookie, (char *)p, n); 110 if (t <= 0) { 111 fp->_flags |= __SERR; 112 return (EOF); 113 } 114 } 115 return (0); 116 } 117