newlib/libc/stdio/fwalk.c

   1 /*
   2  * Copyright (c) 1990 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms are permitted
   6  * provided that the above copyright notice and this paragraph are
   7  * duplicated in all such forms and that any documentation,
   8  * and/or other materials related to such
   9  * distribution and use acknowledge that the software was developed
  10  * by the University of California, Berkeley.  The name of the
  11  * University may not be used to endorse or promote products derived
  12  * from this software without specific prior written permission.
  13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  16  */
  17 /* No user fns here.  Pesch 15apr92. */
  18
  19 #if defined(LIBC_SCCS) && !defined(lint)
  20 static char sccsid[] = "%W% (Berkeley) %G%";
  21 #endif /* LIBC_SCCS and not lint */
  22
  23 #include <_ansi.h>
  24 #include <reent.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <errno.h>
  28
  29 int
  30 _fwalk_sglue (struct _reent *ptr, int (*func) (struct _reent *, FILE *),
  31     struct _glue *g)
  32 {
  33   FILE *fp;
  34   int n, ret = 0;
  35
  36   /*
  37    * It should be safe to walk the list without locking it;
  38    * new nodes are only added to the end and none are ever
  39    * removed.
  40    *
  41    * Avoid locking this list while walking it or else you will
  42    * introduce a potential deadlock in [at least] refill.c.
  43    */
  44   do {
  45     for (fp = g->_iobs, n = g->_niobs; --n >= 0; fp++)
  46       if (fp->_flags != 0 && fp->_flags != 1 && fp->_file != -1)
  47         ret |= (*func) (ptr, fp);
  48     g = g->_next;
  49   } while (g != NULL);
  50
  51   return ret;
  52 }