/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 1987 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
/*LINTLIBRARY*/
#include <stdio.h>
#include <errno.h>
#include <malloc.h>
#include "iob.h"
#define active(iop) ((iop)->_flag & (_IOREAD|_IOWRT|_IORW))
static unsigned char sbuf[NSTATIC][_SBFSIZ];
unsigned char (*_smbuf)[_SBFSIZ] = sbuf;
static FILE **iobglue;
static FILE **endglue;
/*
* Find a free FILE for fopen et al.
* We have a fixed static array of entries, and in addition
* may allocate additional entries dynamically, up to the kernel
* limit on the number of open files.
* At first just check for a free slot in the fixed static array.
* If none are available, then we allocate a structure to glue together
* the old and new FILE entries, which are then no longer contiguous.
*/
FILE *
_findiop(void)
{
FILE **iov, *iop;
FILE *fp;
if(iobglue == NULL) {
for(iop = _iob; iop < _iob + NSTATIC; iop++)
if(!active(iop))
return(iop);
if(_f_morefiles() == 0) {
errno = ENOMEM;
return(NULL);
}
}
iov = iobglue;
while(*iov != NULL && active(*iov))
if (++iov >= endglue) {
errno = EMFILE;
return(NULL);
}
if(*iov == NULL)
*iov = (FILE *)calloc(1, sizeof **iov);
return(*iov);
}
int
_f_morefiles(void)
{
FILE **iov;
FILE *fp;
unsigned char *cp;
int nfiles;
nfiles = getdtablesize();
iobglue = (FILE **)calloc(nfiles, sizeof *iobglue);
if(iobglue == NULL)
return(0);
if((_smbuf = (unsigned char (*)[_SBFSIZ])malloc(nfiles * sizeof *_smbuf)) == NULL) {
free((char *)iobglue);
iobglue = NULL;
return(0);
}
endglue = iobglue + nfiles;
for(fp = _iob, iov = iobglue; fp < &_iob[NSTATIC]; /* void */)
*iov++ = fp++;
return(1);
}
void
f_prealloc(void)
{
FILE **iov;
FILE *fp;
if(iobglue == NULL && _f_morefiles() == 0)
return;
for(iov = iobglue; iov < endglue; iov++)
if(*iov == NULL)
*iov = (FILE *)calloc(1, sizeof **iov);
}
void
_fwalk(int (*function)(FILE *))
{
FILE **iov;
FILE *fp;
if(function == NULL)
return;
if(iobglue == NULL) {
for(fp = _iob; fp < &_iob[NSTATIC]; fp++)
if(active(fp))
(*function)(fp);
} else {
for(iov = iobglue; iov < endglue; iov++)
if(*iov && active(*iov))
(*function)(*iov);
}
}