[apple/libc.git] / stdio / FreeBSD / findfp.c

/*-
 * 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.
 */

#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: src/lib/libc/stdio/findfp.c,v 1.29 2004/05/22 15:19:41 tjr Exp $");

#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) \
  	{0,0,0,flags,file,{0},0,__sF+file,__sclose,__sread,__sseek,__swrite, \
	 {0}, __sFX + file}
  /*	 p r w flags file _bf z  cookie      close    read    seek    write */
  /*     _ub _extra */
				/* the usual - (stdin + stdout + stderr) */
static FILE usual[FOPEN_MAX - 3];
static struct __sFILEX usual_extra[FOPEN_MAX - 3];
static struct glue uglue = { NULL, FOPEN_MAX - 3, usual };

static struct __sFILEX __sFX[3];

/*
 * We can't make this 'static' until 6.0-current due to binary
 * compatibility concerns.  This also means we cannot change the
 * sizeof(FILE) until that time either and must continue to use the
 * __sFILEX stuff to add to FILE.
 */
FILE __sF[3] = {
	std(__SRD, STDIN_FILENO),
	std(__SWR, STDOUT_FILENO),
	std(__SWR|__SNBF, STDERR_FILENO)
};

/*
 * The following kludge is done to ensure enough binary compatibility
 * with future versions of libc.  Or rather it allows us to work with
 * libraries that have been built with a newer libc that defines these
 * symbols and expects libc to provide them.  We only have need to support
 * i386 and alpha because they are the only "old" systems we have deployed.
 */
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;
	static struct __sFILEX emptyx;
	FILE *p;
	struct __sFILEX *fx;

	g = (struct glue *)malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE) +
	    n * sizeof(struct __sFILEX));
	if (g == NULL)
		return (NULL);
	p = (FILE *)ALIGN(g + 1);
	fx = (struct __sFILEX *)&p[n];
	g->next = NULL;
	g->niobs = n;
	g->iobs = p;
	while (--n >= 0) {
		*p = empty;
		p->_extra = fx;
		*p->_extra = emptyx;
		p++, fx++;
	}
	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->_extra->orientation = 0;
	memset(&fp->_extra->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()
{
	int	i;

	THREAD_LOCK();
	if (__sdidinit == 0) {
		/* Set _extra for the usual suspects. */
		for (i = 0; i < FOPEN_MAX - 3; i++)
			usual[i]._extra = &usual_extra[i];

		/* Make sure we clean up on exit. */
		__cleanup = _cleanup;		/* conservative */
		__sdidinit = 1;
	}
	THREAD_UNLOCK();
}
Commit	Line	Data
9385eb3d	1	/*-
e9ce8d39 A	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. All advertising materials mentioning features or use of this software
	17	* must display the following acknowledgement:
	18	* This product includes software developed by the University of
	19	* California, Berkeley and its contributors.
	20	* 4. Neither the name of the University nor the names of its contributors
	21	* may be used to endorse or promote products derived from this software
	22	* without specific prior written permission.
	23	*
	24	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	* SUCH DAMAGE.
	35	*/
	36
9385eb3d A	37	#if defined(LIBC_SCCS) && !defined(lint)
	38	static char sccsid[] = "@(#)findfp.c 8.2 (Berkeley) 1/4/94";
	39	#endif /* LIBC_SCCS and not lint */
	40	#include <sys/cdefs.h>
3d9156a7	41	__FBSDID("$FreeBSD: src/lib/libc/stdio/findfp.c,v 1.29 2004/05/22 15:19:41 tjr Exp $");
e9ce8d39 A	42
e9ce8d39 A	43	#include <sys/param.h>
9385eb3d	44	#include <machine/atomic.h>
e9ce8d39 A	45	#include <unistd.h>
e9ce8d39 A	46	#include <stdio.h>
e9ce8d39 A	47	#include <stdlib.h>
e9ce8d39 A	48	#include <string.h>
9385eb3d A	49
	50	#include <spinlock.h>
	51
	52	#include "libc_private.h"
e9ce8d39 A	53	#include "local.h"
	54	#include "glue.h"
	55
9385eb3d	56	int __sdidinit;
e9ce8d39 A	57
	58	#define NDYNAMIC 10 /* add ten more whenever necessary */
	59
	60	#define std(flags, file) \
9385eb3d A	61	{0,0,0,flags,file,{0},0,__sF+file,__sclose,__sread,__sseek,__swrite, \
	62	{0}, __sFX + file}
	63	/* p r w flags file _bf z cookie close read seek write */
	64	/* _ub _extra */
e9ce8d39 A	65	/* the usual - (stdin + stdout + stderr) */
e9ce8d39 A	66	static FILE usual[FOPEN_MAX - 3];
9385eb3d A	67	static struct __sFILEX usual_extra[FOPEN_MAX - 3];
9385eb3d A	68	static struct glue uglue = { NULL, FOPEN_MAX - 3, usual };
e9ce8d39	69
9385eb3d A	70	static struct __sFILEX __sFX[3];
	71
	72	/*
	73	* We can't make this 'static' until 6.0-current due to binary
	74	* compatibility concerns. This also means we cannot change the
	75	* sizeof(FILE) until that time either and must continue to use the
	76	* __sFILEX stuff to add to FILE.
	77	*/
e9ce8d39	78	FILE __sF[3] = {
9385eb3d A	79	std(__SRD, STDIN_FILENO),
	80	std(__SWR, STDOUT_FILENO),
	81	std(__SWR\|__SNBF, STDERR_FILENO)
e9ce8d39	82	};
9385eb3d A	83
	84	/*
	85	* The following kludge is done to ensure enough binary compatibility
	86	* with future versions of libc. Or rather it allows us to work with
	87	* libraries that have been built with a newer libc that defines these
	88	* symbols and expects libc to provide them. We only have need to support
	89	* i386 and alpha because they are the only "old" systems we have deployed.
	90	*/
	91	FILE *__stdinp = &__sF[0];
	92	FILE *__stdoutp = &__sF[1];
	93	FILE *__stderrp = &__sF[2];
	94
e9ce8d39	95	struct glue __sglue = { &uglue, 3, __sF };
9385eb3d A	96	static struct glue *lastglue = &uglue;
	97
	98	static struct glue * moreglue(int);
	99
	100	static spinlock_t thread_lock = _SPINLOCK_INITIALIZER;
	101	#define THREAD_LOCK() if (__isthreaded) _SPINLOCK(&thread_lock)
	102	#define THREAD_UNLOCK() if (__isthreaded) _SPINUNLOCK(&thread_lock)
	103
	104	#if NOT_YET
	105	#define SET_GLUE_PTR(ptr, val) atomic_set_rel_ptr(&(ptr), (uintptr_t)(val))
	106	#else
	107	#define SET_GLUE_PTR(ptr, val) ptr = val
	108	#endif
e9ce8d39 A	109
	110	static struct glue *
	111	moreglue(n)
9385eb3d	112	int n;
e9ce8d39	113	{
9385eb3d	114	struct glue *g;
e9ce8d39	115	static FILE empty;
9385eb3d A	116	static struct __sFILEX emptyx;
	117	FILE *p;
	118	struct __sFILEX *fx;
e9ce8d39	119
9385eb3d A	120	g = (struct glue )malloc(sizeof(g) + ALIGNBYTES + n * sizeof(FILE) +
9385eb3d A	121	n * sizeof(struct __sFILEX));
e9ce8d39 A	122	if (g == NULL)
	123	return (NULL);
	124	p = (FILE *)ALIGN(g + 1);
9385eb3d	125	fx = (struct __sFILEX *)&p[n];
e9ce8d39 A	126	g->next = NULL;
	127	g->niobs = n;
	128	g->iobs = p;
9385eb3d A	129	while (--n >= 0) {
	130	*p = empty;
	131	p->_extra = fx;
	132	*p->_extra = emptyx;
	133	p++, fx++;
	134	}
e9ce8d39 A	135	return (g);
	136	}
	137
	138	/*
	139	* Find a free FILE for fopen et al.
	140	*/
	141	FILE *
	142	__sfp()
	143	{
9385eb3d A	144	FILE *fp;
	145	int n;
	146	struct glue *g;
e9ce8d39 A	147
	148	if (!__sdidinit)
	149	__sinit();
9385eb3d A	150	/*
	151	* The list must be locked because a FILE may be updated.
	152	*/
	153	THREAD_LOCK();
	154	for (g = &__sglue; g != NULL; g = g->next) {
e9ce8d39 A	155	for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
	156	if (fp->_flags == 0)
	157	goto found;
e9ce8d39	158	}
9385eb3d A	159	THREAD_UNLOCK(); /* don't hold lock while malloc()ing. */
	160	if ((g = moreglue(NDYNAMIC)) == NULL)
	161	return (NULL);
	162	THREAD_LOCK(); /* reacquire the lock */
	163	SET_GLUE_PTR(lastglue->next, g); /* atomically append glue to list */
	164	lastglue = g; /* not atomic; only accessed when locked */
	165	fp = g->iobs;
e9ce8d39 A	166	found:
e9ce8d39 A	167	fp->_flags = 1; /* reserve this slot; caller sets real flags */
9385eb3d	168	THREAD_UNLOCK();
e9ce8d39 A	169	fp->_p = NULL; /* no current pointer */
	170	fp->_w = 0; /* nothing to read or write */
	171	fp->_r = 0;
	172	fp->_bf._base = NULL; /* no buffer */
	173	fp->_bf._size = 0;
	174	fp->_lbfsize = 0; /* not line buffered */
	175	fp->_file = -1; /* no file */
	176	/* fp->_cookie = <any>; / / caller sets cookie, _read/_write etc */
	177	fp->_ub._base = NULL; /* no ungetc buffer */
	178	fp->_ub._size = 0;
	179	fp->_lb._base = NULL; /* no line buffer */
	180	fp->_lb._size = 0;
9385eb3d A	181	/* fp->_lock = NULL; / / once set always set (reused) */
9385eb3d A	182	fp->_extra->orientation = 0;
3d9156a7	183	memset(&fp->_extra->mbstate, 0, sizeof(mbstate_t));
e9ce8d39 A	184	return (fp);
	185	}
	186
	187	/*
	188	* XXX. Force immediate allocation of internal memory. Not used by stdio,
	189	* but documented historically for certain applications. Bad applications.
	190	*/
9385eb3d A	191	__warn_references(f_prealloc,
	192	"warning: this program uses f_prealloc(), which is not recommended.");
	193
e9ce8d39 A	194	void
	195	f_prealloc()
	196	{
9385eb3d	197	struct glue *g;
e9ce8d39 A	198	int n;
	199
	200	n = getdtablesize() - FOPEN_MAX + 20; /* 20 for slop. */
9385eb3d A	201	/*
	202	* It should be safe to walk the list without locking it;
	203	* new nodes are only added to the end and none are ever
	204	* removed.
	205	*/
e9ce8d39 A	206	for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next)
e9ce8d39 A	207	/* void */;
9385eb3d A	208	if ((n > 0) && ((g = moreglue(n)) != NULL)) {
	209	THREAD_LOCK();
	210	SET_GLUE_PTR(lastglue->next, g);
	211	lastglue = g;
	212	THREAD_UNLOCK();
	213	}
e9ce8d39 A	214	}
	215
	216	/*
	217	* exit() calls _cleanup() through *__cleanup, set whenever we
	218	* open or buffer a file. This chicanery is done so that programs
	219	* that do not use stdio need not link it all in.
	220	*
	221	* The name `_cleanup' is, alas, fairly well known outside stdio.
	222	*/
	223	void
	224	_cleanup()
	225	{
	226	/* (void) _fwalk(fclose); */
	227	(void) _fwalk(__sflush); /* `cheating' */
	228	}
	229
	230	/*
	231	* __sinit() is called whenever stdio's internal variables must be set up.
	232	*/
	233	void
	234	__sinit()
	235	{
9385eb3d A	236	int i;
	237
	238	THREAD_LOCK();
	239	if (__sdidinit == 0) {
	240	/* Set _extra for the usual suspects. */
	241	for (i = 0; i < FOPEN_MAX - 3; i++)
	242	usual[i]._extra = &usual_extra[i];
	243
	244	/* Make sure we clean up on exit. */
	245	__cleanup = _cleanup; /* conservative */
	246	__sdidinit = 1;
	247	}
	248	THREAD_UNLOCK();
e9ce8d39	249	}