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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.
* 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)findfp.c 8.2 (Berkeley) 1/4/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <machine/atomic.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <spinlock.h>
#include "libc_private.h"
#include "local.h"
#include "glue.h"
int __sdidinit;
#define NDYNAMIC 10 /* add ten more whenever necessary */
#define std(flags, file) { \
._flags = (flags), \
._file = (file), \
._cookie = __sF + (file), \
._close = __sclose, \
._read = __sread, \
._seek = __sseek, \
._write = __swrite, \
}
/* the usual - (stdin + stdout + stderr) */
static FILE usual[FOPEN_MAX - 3];
static struct glue uglue = { NULL, FOPEN_MAX - 3, usual };
static FILE __sF[3] = {
std(__SRD, STDIN_FILENO),
std(__SWR, STDOUT_FILENO),
std(__SWR|__SNBF, STDERR_FILENO)
};
FILE *__stdinp = &__sF[0];
FILE *__stdoutp = &__sF[1];
FILE *__stderrp = &__sF[2];
struct glue __sglue = { &uglue, 3, __sF };
static struct glue *lastglue = &uglue;
static struct glue * moreglue(int);
static spinlock_t thread_lock = _SPINLOCK_INITIALIZER;
#define THREAD_LOCK() if (__isthreaded) _SPINLOCK(&thread_lock)
#define THREAD_UNLOCK() if (__isthreaded) _SPINUNLOCK(&thread_lock)
#if NOT_YET
#define SET_GLUE_PTR(ptr, val) atomic_set_rel_ptr(&(ptr), (uintptr_t)(val))
#else
#define SET_GLUE_PTR(ptr, val) ptr = val
#endif
static struct glue *
moreglue(n)
int n;
{
struct glue *g;
static FILE empty;
FILE *p;
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;
return (g);
}
/*
* Find a free FILE for fopen et al.
*/
FILE *
__sfp()
{
FILE *fp;
int n;
struct glue *g;
if (!__sdidinit)
__sinit();
/*
* The list must be locked because a FILE may be updated.
*/
THREAD_LOCK();
for (g = &__sglue; g != NULL; g = g->next) {
for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
if (fp->_flags == 0)
goto found;
}
THREAD_UNLOCK(); /* don't hold lock while malloc()ing. */
if ((g = moreglue(NDYNAMIC)) == NULL)
return (NULL);
THREAD_LOCK(); /* reacquire the lock */
SET_GLUE_PTR(lastglue->next, g); /* atomically append glue to list */
lastglue = g; /* not atomic; only accessed when locked */
fp = g->iobs;
found:
fp->_flags = 1; /* reserve this slot; caller sets real flags */
THREAD_UNLOCK();
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;
/* fp->_lock = NULL; */ /* once set always set (reused) */
fp->_orientation = 0;
memset(&fp->_mbstate, 0, sizeof(mbstate_t));
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 not recommended.");
void
f_prealloc()
{
struct glue *g;
int n;
n = getdtablesize() - FOPEN_MAX + 20; /* 20 for slop. */
/*
* It should be safe to walk the list without locking it;
* new nodes are only added to the end and none are ever
* removed.
*/
for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next)
/* void */;
if ((n > 0) && ((g = moreglue(n)) != NULL)) {
THREAD_LOCK();
SET_GLUE_PTR(lastglue->next, g);
lastglue = g;
THREAD_UNLOCK();
}
}
/*
* 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()
{
/* Make sure we clean up on exit. */
__cleanup = _cleanup; /* conservative */
__sdidinit = 1;
}
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