--- /dev/null
+/*-
+ * 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 1.28 2002/11/14 14:06:14 imp 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;
+#ifdef notdef
+ /* Stateful encoding/decoding is not yet supported. */
+ memset(&fp->_extra->wstate, 0, sizeof(mbstate_t));
+ memset(&fp->_extra->rstate, 0, sizeof(mbstate_t));
+#endif
+ 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();
+}
projects / apple / libc.git / blobdiff