/* $NetBSD: findfp.c,v 1.19 2003/07/18 21:46:41 nathanw Exp $ */ /*- * 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. */ #include #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char sccsid[] = "@(#)findfp.c 8.2 (Berkeley) 1/4/94"; #else __RCSID("$NetBSD: findfp.c,v 1.19 2003/07/18 21:46:41 nathanw Exp $"); #endif #endif /* LIBC_SCCS and not lint */ #include "namespace.h" #include #include #include #include #include #include #include "reentrant.h" #include "local.h" #include "glue.h" int __sdidinit; #define NDYNAMIC 10 /* add ten more whenever necessary */ #define std(flags, file) \ /* p r w flags file bf lfbsize cookie close */ \ { NULL, 0, 0, flags, file, { NULL, 0 }, 0, __sF + file, __sclose, \ /* read seek write ext up */ \ __sread, __sseek, __swrite, { (void *)(__sFext + file), 0 }, NULL, \ /* ur ubuf, nbuf lb blksize offset */ \ 0, { '\0', '\0', '\0' }, { '\0' }, { NULL, 0 }, 0, (fpos_t)0 } /* the usual - (stdin + stdout + stderr) */ static FILE usual[FOPEN_MAX - 3]; static struct __sfileext usualext[FOPEN_MAX - 3]; static struct glue uglue = { 0, FOPEN_MAX - 3, usual }; #ifdef _REENTRANT #define STDEXT { {0}, {{{0}}}, MUTEX_INITIALIZER, COND_INITIALIZER, NULL, 0, 0} struct __sfileext __sFext[3] = { STDEXT, STDEXT, STDEXT}; #else struct __sfileext __sFext[3]; #endif FILE __sF[3] = { std(__SRD, STDIN_FILENO), /* stdin */ std(__SWR, STDOUT_FILENO), /* stdout */ std(__SWR|__SNBF, STDERR_FILENO) /* stderr */ }; struct glue __sglue = { &uglue, 3, __sF }; static struct glue *moreglue __P((int)); void f_prealloc __P((void)); #ifdef _REENTRANT rwlock_t __sfp_lock = RWLOCK_INITIALIZER; #endif static struct glue * moreglue(n) int n; { struct glue *g; FILE *p; struct __sfileext *pext; static FILE empty; g = (struct glue *)malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE) + n * sizeof(struct __sfileext)); if (g == NULL) return (NULL); p = (FILE *)ALIGN((u_long)(g + 1)); g->next = NULL; g->niobs = n; g->iobs = p; pext = (void *)(p + n); while (--n >= 0) { *p = empty; _FILEEXT_SETUP(p, pext); p++; pext++; } return (g); } /* * Find a free FILE for fopen et al. */ FILE * __sfp() { FILE *fp; int n; struct glue *g; if (!__sdidinit) __sinit(); rwlock_wrlock(&__sfp_lock); 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; } rwlock_unlock(&__sfp_lock); 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 = ; */ /* caller sets cookie, _read/_write etc */ _UB(fp)._base = NULL; /* no ungetc buffer */ _UB(fp)._size = 0; fp->_lb._base = NULL; /* no line buffer */ fp->_lb._size = 0; memset(WCIO_GET(fp), 0, sizeof(struct wchar_io_data)); rwlock_unlock(&__sfp_lock); return (fp); } /* * XXX. Force immediate allocation of internal memory. Not used by stdio, * but documented historically for certain applications. Bad applications. */ void f_prealloc() { struct glue *g; int n; n = (int)sysconf(_SC_OPEN_MAX) - 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) fflush(NULL); /* `cheating' */ } /* * __sinit() is called whenever stdio's internal variables must be set up. */ void __sinit() { int i; for (i = 0; i < FOPEN_MAX - 3; i++) _FILEEXT_SETUP(&usual[i], &usualext[i]); /* make sure we clean up on exit */ __cleanup = _cleanup; /* conservative */ __sdidinit = 1; }