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/*-
 * Copyright (c) 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * 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, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 */

/* MODIFIED:
 * -- added _THREAD_SAFE an all similar stuff
 * -- modified initialization and termination
 */

#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)findfp.c    8.2 (Berkeley) 1/4/94";
#endif
static const char rcsid[] =
                "$\Id: findfp.c,v 1.3 1996/06/22 10:33:12 jraynard Exp $";
#endif /* LIBC_SCCS and not lint */

#ifdef _THREAD_SAFE
#include <kernel/func.h>
#include <kernel/model.h>
static NOPM_mutexattr_t mutexattr=NOPM_MUTEXATTR_INITIALIZER;
#endif

#include <sys/param.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "local.h"
#include "glue.h"

/* MG (added =0) */
int     __sdidinit=0;

#define NDYNAMIC 10             /* add ten more whenever necessary */

#define std(flags, file) \
        {0,0,0,flags,file,{0},0,__sF+file,__sclose,__sread,__sseek,__swrite}
/*       p r w flags file _bf z  cookie      close    read    seek    write */

                                /* the usual - (stdin + stdout + stderr) */
static FILE usual[FOPEN_MAX - 3];
static struct glue uglue = { 0, FOPEN_MAX - 3, usual };

FILE __sF[3] = {
        std(__SRD|__SLBF, STDIN_FILENO),        /* stdin */
        std(__SWR|__SLBF, STDOUT_FILENO),       /* stdout */
        std(__SWR|__SNBF, STDERR_FILENO)        /* stderr */
};
struct glue __sglue = { &uglue, 3, __sF };

static struct glue *    moreglue __P((int));

static struct glue *
moreglue(n)
        register int n;
{
        register struct glue *g;
        register FILE *p;
        static FILE empty;

        g = (struct glue *)malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE));
        if (g == NULL)
                return (NULL);
        p = (FILE *)ALIGN(g + 1);
        g->next = NULL;
        g->niobs = n;
        g->iobs = p;
        while (--n >= 0) {
                *p = empty;
#ifdef _THREAD_SAFE
                mutex_init(&p->_mutex,&mutexattr);             
#endif
                p++;
        }
        return (g);
}

/*
 * Find a free FILE for fopen et al.
 */
FILE *
__sfp()
{
        register FILE *fp;
        register int n;
        register struct glue *g;

        if (!__sdidinit)
                __sinit();
        for (g = &__sglue;; g = g->next) {
                for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
                        if (fp->_flags == 0)
                                goto found;
                if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL)
                        break;
        }
        return (NULL);
found:
        fp->_flags = 1;         /* reserve this slot; caller sets real flags */
        fp->_p = NULL;          /* no current pointer */
        fp->_w = 0;             /* nothing to read or write */
        fp->_r = 0;
        fp->_bf._base = NULL;   /* no buffer */
        fp->_bf._size = 0;
        fp->_lbfsize = 0;       /* not line buffered */
        fp->_file = -1;         /* no file */
/*      fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */
        fp->_ub._base = NULL;   /* no ungetc buffer */
        fp->_ub._size = 0;
        fp->_lb._base = NULL;   /* no line buffer */
        fp->_lb._size = 0;

        return (fp);
}

/*
 * XXX.  Force immediate allocation of internal memory.  Not used by stdio,
 * but documented historically for certain applications.  Bad applications.
 */
__warn_references(f_prealloc,
        "warning: this program uses f_prealloc(), which is stupid.");

void
f_prealloc()
{
        register struct glue *g;
        int n;

        n = getdtablesize() - FOPEN_MAX + 20;           /* 20 for slop. */
        for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next)
                /* void */;
        if (n > 0)
                g->next = moreglue(n);
}

/*
 * exit() calls _cleanup() through *__cleanup, set whenever we
 * open or buffer a file.  This chicanery is done so that programs
 * that do not use stdio need not link it all in.
 *
 * The name `_cleanup' is, alas, fairly well known outside stdio.
 */
void
_cleanup()
{
        /* (void) _fwalk(fclose); */
        (void) _fwalk(__sflush);                /* `cheating' */
}

/*
 * __sinit() is called whenever stdio's internal variables must be set up.
 */
void
__sinit()
{
#ifdef _THREAD_SAFE
  register FILE *fp;
  register int n;
  register struct glue *g;
#endif
 
  /* make sure we clean up on exit */
  __cleanup = _cleanup;         /* conservative */
  __sdidinit = 1;

#ifdef _THREAD_SAFE
  for (g = &__sglue;; g = g->next) {
    for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
      mutex_init(&fp->_mutex,&mutexattr);
    if (g->next == NULL) break;
  }
#endif
 
}