lib/libc/stdio/fwalk.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Chris Torek.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * @(#)fwalk.c  8.1 (Berkeley) 6/4/93
  33  * $FreeBSD: src/lib/libc/stdio/fwalk.c,v 1.10 2007/01/09 00:28:06 imp Exp $
  34  */
  35
  36 #include <sys/types.h>
  37 #include <machine/atomic.h>
  38 #include <stdio.h>
  39 #include "local.h"
  40
  41 int
  42 _fwalk(int (*function)(FILE *))
  43 {
  44         FILE *fp;
  45         int n, ret;
  46         struct glue *g;
  47
  48         ret = 0;
  49         /*
  50          * It should be safe to walk the list without locking it;
  51          * new nodes are only added to the end and none are ever
  52          * removed.
  53          *
  54          * Avoid locking this list while walking it or else you will
  55          * introduce a potential deadlock in [at least] refill.c.
  56          */
  57         for (g = &__sglue; g != NULL; g = g->next)
  58                 for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
  59                         if ((fp->pub._flags != 0) &&
  60                             ((fp->pub._flags & __SIGN) == 0))
  61                                 ret |= (*function)(fp);
  62         return (ret);
  63 }